WO2017205939A1 - Vitamin d formulations and therapeutic uses thereof - Google Patents

Abstract

The present invention provides a formulation comprising: Vitamin D, or a salt, derivative or metabolite thereof; one or more polyethylene glycols having a molecular weight of about 1000- 4000 Da; and one or more polyethylene glycols having a molecular weight of about 500-800 Da. The formulation may be configured to be administered by retention in the buccal cavity, and particularly in the sublingual region of the buccal cavity. Also provides are methods of treating or preventing a condition associated with a deficiency in or resistance to Vitamin D or a derivative or a metabolite thereof, comprising the step of administering to a subject the present formulations. The condition associated with a deficiency in or resistance to Vitamin D, or a derivative or a metabolite thereof may be a bone mineralisation disorder or a bone remodelling disorder, or a mineral metabolism disorder.

Description

VITAMIN D FORMULATIONS AND THERAPEUTIC USES THEREOF

FIELD OF THE INVENTION

The present invention relates generally to oral formulations, and in particular to peroral formulations for the delivery of Vitamin D. The present invention further provides methods and uses of the said formulations in the treatment and/or prevention of conditions associated with Vitamin D deficiency and for Vitamin D supplementation.

BACKGROUND TO THE INVENTION

The term "Vitamin D" collectively refers to a group of fat-soluble secosteroids which are primarily involved for intestinal absorption of calcium and phosphate. But it is typically understood that metabolites of Vitamin D₂ (ergocalciferol) and Vitamin D₃ (cholecalciferol) directly contribute to the maintenance of normal levels of calcium and phosphorus in the bloodstream. These Vitamin D metabolites known as 25- hydroxyvitamin D₂ and 25-hydroxy vitamin D₃ (collectively referred to as "25- hydroxyvitamin D" yet 25-hydroxyvitamin D₃ is also known as calcifediol, calcidiol, 25- hydroxy cholecalciferol; also abbreviated as 25(OH)D), are prohormones that are produced in the liver by hydroxylation of Vitamin D₂ and Vitamin D₃ respectively. Calcifediol is the main metabolite measured by physicians worldwide to determine a patient's Vitamin D status.

25-hydroxyvitamin D may be further metabolised in the kidneys into potent hormones, such as la,25-dihydroxyvitamin D₃ (from 25-hydroxyvitamin D₂) and la,25- dihydroxyvitamin D₃ (calcitriol) (from 25-hydroxyvitamin D₃)).

The human health effects of Vitamin D are mediated by intracellular Vitamin D receptors (VDR). Vitamin D hormones regulate blood calcium levels by controlling the absorption of dietary calcium by the small intestine and the reabsorption of calcium by the kidneys. Excessive hormone levels, whether transient or prolonged, can lead to abnormally elevated urine calcium (hypercalciuria), blood calcium (hypercalcemia) and blood phosphorus (hyperphosphatemia). The Vitamin D hormones also participate in the regulation of cellular differentiation and growth, PTH secretion by the parathyroid glands, and normal bone formation and metabolism. Further, Vitamin D hormones are required for the normal functioning of the musculoskeletal, immune and renin-angiotensin systems.

The actions of Vitamin D hormones on specific tissues depend on the degree to which they bind to (or occupy) the intracellular VDR in those tissues.

Surges in blood or intracellular prohormone concentrations can promote excessive extrarenal hormone production, leading to local adverse effects on calcium and phosphorus metabolism. They also can inhibit hepatic prohormone production from Vitamin D, and promote catabolism of both Vitamin D and 25-hydroxyvitamin D in the kidney and/or other tissues.

Production of 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃ declines when Vitamin D is in short supply, as in conditions such as Vitamin D insufficiency or Vitamin D deficiency (alternatively, hypo vitamino sis D). Low production of 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃ leads to low blood levels of 25-hydroxyvitamin D.

Inadequate Vitamin D supply often develops in individuals who are infrequently exposed to sunlight without protective sunscreens, have chronically inadequate intakes of Vitamin D, or suffer from conditions that reduce the intestinal absorption of fat soluble vitamins (such as Vitamin D). Inadequate Vitamin D supply can cause serious bone disorders, including rickets and osteomalacia, and may contribute to the development of many other disorders including osteoporosis, non-traumatic fractures of the spine and hip, obesity, diabetes, muscle weakness, immune deficiencies, hypertension, psoriasis, and various cancers.

One condition for which vitamin D plays an important role is chronic kidney disease (CKD). CKD results in a cascade of changes in mineral metabolism, which leads to a rise in circulating parathyroid hormone (PTH) and the characteristic abnormalities of secondary hyperparathyroidism (SHPT). Management of elevated PTH levels has been a focus of therapy in CKD for over 40 years. SHPT is associated with morbidity and mortality in patients with CKD stages 3-5D, and observational studies consistently report an increased relative risk of death in dialysis patients who have PTH values at the extremes (less than two or greater than nine times the upper normal limit of the assay). Once developed, severe SHPT may be resistant to medical/pharmacological therapy, and marked parathyroid hyperplasia when associated with hypercalcaemia necessitates treatment with a parathyroidectomy.

CKD is characterised by low levels of 25-hydroxyvitamin D (25(OH)D or calcidiol) and 1,25-dihydroxycholecalciferol (l,25(OH)2D or calcitriol), as well as vitamin D resistance, all contributing to SHPT. Treatment with 'active' vitamin D, either calcitriol or vitamin D receptor analogues (VDRAs), has been the cornerstone for the prevention and management of SHPT in patients with CKD. Observational data suggests a mortality benefit with the use of VDRAs in dialysis populations.

Emerging literature suggests that adherence to daily vitamin D supplementation may be an important factor influencing vitamin D status, and compliance with therapies for bone health (like other asymptomatic conditions) is a major challenge. Chronic diseases, such as poor bone health, as well as suboptimal vitamin D status, have been associated with reduced quality of life. Despite the potential for improved functional ability and independence, only 50-69% of individuals prescribed osteoporosis medications (e.g. bisphosphonates, vitamin D and calcium) comply to them regularly (e.g. consume 80% of the time), and only 25-35% are compliant for more than one year. This suggests that current modes of vitamin D supplementation, particularly low dose daily administration (<1,000 IU/d), may be ineffective at optimising vitamin D status.

Currently available oral Vitamin D supplements are far from ideal for achieving and maintaining optimal blood 25-hydroxyvitamin D levels. Vitamin D and its metabolites are highly water insoluble and the formulations to date have concentrated on insoluble excipients which often give the resultant formulation a gritty feel after, for instance, disintegration in the oral cavity. This in turn causes problems with palatability which ultimately leads to non-compliance issues, as mentioned supra with reference to CKD. Other potential problems with prior art formulations include excessively long disintegration times and inadequate mechanical resistance.

Alternative approaches to Vitamin D delivery and supplementation is needed given the problems encountered with both currently available oral Vitamin D supplements, and with previously used oral 25-hydroxyvitamin D₃. The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

SUMMARY OF THE INVENTION

After considering this description it will be apparent to one skilled in the art how the invention is implemented in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention. Furthermore, statements of advantages or other aspects apply to specific exemplary embodiments, and not necessarily to all embodiments covered by the claims.

Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may.

It is not represented that all embodiments of the invention have all advantages disclosed herein. Some embodiments may have a single advantage while other embodiments may have no advantage and are merely useful alternatives to the prior art.

In a first aspect, but not necessarily the broadest aspect, the present invention comprises a formulation comprising:

(i) Vitamin D, or a salt, derivative or metabolite thereof; (ii) one or more polyethylene glycols having a molecular weight of about 1000-4000; and

(iii) one or more polyethylene glycols having a molecular weight of about 500-800.

In one embodiment of the first aspect, the formulation comprises one or more bio adhesive agents selected from the group consisting of polyvinylpyrrolidone, carbomers, acacia powder, guar gum, gum karaya, hydro xypropyl cellulose, hydro xypropyl methylcellulose, polycarbophils, corn starch, chitosan and derivative thereof, and sodium alginate.

In one embodiment of the first aspect, the formulation comprises:

(i) one or more lubricants; and/or

(ii) one or more disintegrating agents; and/or

(iii) one or more binding agents; and/or

(iv) one or more taste masking agents.

In one embodiment of the first aspect, the formulation is in the form of a direct compression tablet.

In one embodiment of the first aspect, the Vitamin D is a metabolite.

In one embodiment of the first aspect, the metabolite is cholecalciferol (Vitamin D3), calcifediol or calcitriol.

In one embodiment of the first aspect, the metabolite is calcifediol.

In one embodiment of the first aspect, the calcifediol is present in an amount of between about 500 IU and about 1500 IU, or between about 600 IU and about 1400 IU, or between about 700 IU and about 1300 IU, or between about 800 IU and about 1200 IU, or between about 900 IU and about 1100 IU, or about 1000 IU.

In one embodiment of the first aspect, the disintegration time of the formulation is less than about 3 minutes, or less than about 2 minutes or less than about 1 minute.

In a second aspect, the present invention provides a method of treating or preventing a condition associated with a deficiency in or resistance to Vitamin D or a derivative or a metabolite thereof, the method comprising the steps of administering to a subject in need thereof the formulation of any one of claims 1 to 7.

In one embodiment of the second aspect, the condition associated with a deficiency in or resistance to Vitamin D, or a derivative or a metabolite thereof is a bone mineralisation disorder or a bone remodelling disorder or a mineral metabolism disorder.

In one embodiment of the second aspect, the condition associated with a deficiency in or resistance to Vitamin D, or a derivative or a metabolite thereof is secondary hyperparathyroidism.

In one embodiment of the second aspect, the formulation is disposed in and retained in the buccal cavity or sublingual region thereof until most or substantially all of the formulation disintegrates.

In one embodiment of the second aspect, the disintegration time is less than about 3 minutes, or less than about 2 minutes or less than about 1 minute.

In one embodiment of the second aspect, the Vitamin D, or a derivative or a metabolite thereof is selected from the group consisting of cholecalciferol, calcifediol and calcitriol.

In one embodiment of the second aspect, the Vitamin D, or a derivative or a metabolite thereof is calcifediol.

In one embodiment of the second aspect, the calcifediol administered to the subject at a rate of between about 500 IU and about 1500 IU, or between about 600 IU and about 1400 IU, or between about 700 IU and about 1300 IU, or between about 800 IU and about 1200 IU, or between about 900 IU and about 1100 IU, or about 1000 IU per day.

In one embodiment of the second aspect, the formulation is administered at a maximum rate of once per day.

In a third aspect, the present invention provides a method of preparing a formulation according comprising Vitamin D, or a salt, derivative or metabolite thereof, said method including the steps of: a) dissolving the Vitamin D, or a salt, derivative or metabolite thereof in a quantity of one or more polyethylene glycols having a molecular weight about 500-800; and

b) melting a quantity of one or more polyethylene glycols having a molecular weight of about 1000-4000 and adding the resultant melt to the mixture obtained from a).

In one embodiment of the third aspect, the resultant mixture from step b) is cooled to produce a solid.

In one embodiment of the third aspect, the solid is mixed with the remaining ingredients and subjected to direct compression.

In one embodiment, the present invention provides methods for effectively and safely restoring blood 25-hydroxyvitamin D levels to optimal levels (defined for patients as >30 ng/mL 25-hydroxyvitamin D) and maintaining blood 25-hydroxyvitamin D levels at such optimal levels. The method includes dosing a subject, an animal or a human patient, with sufficient 25-hydroxyvitamin D₂ or 25-hydroxyvitamin D₃ or any combination of these two prohormones. In an embodiment, the active is a Vitamin D metabolite which is cholecalciferol (Vitamin D3). In another embodiment the active is a Vitamin D metabolite and which is calcifediol.

In an embodiment, the one or more polyethylene glycol having a molecular weight of about 1000-4000 is selected from one or more of the group consisting of PEG 1500, PEG 1450, and PEG 3350.

In an embodiment (ii) is one or more polyethylene glycols having a molecular weight of about 1000-2000.

In an embodiment the total amount of the one or more polyethylene glycol having a molecular weight of about 1000-4000, for instance, 1000-2000, is about 0.5-15.0 % wt/wt of the total formulations, such as about 0.5 % wt/wt, 0.6 % wt/wt, 0.7 % wt/wt, 0.8 % wt/wt, 0.9 % wt/wt, 1.0 % wt/wt, 1.1 % wt/wt, 1.2 % wt/wt, 1.3 % wt/wt, 1.4 % wt/wt, 1.5 % wt/wt, 1.6 % wt/wt, 1.7 % wt/wt, 1.8 % wt/wt, 1.9 % wt/wt, 2.0 % wt/wt, 2.1 % wt/wt, 2.2 % wt/wt, 2.3 % wt/wt, 2.4 % wt/wt, 2.5 % wt/wt, 2.6 % wt/wt, 2.7 % wt/wt, 2.8 % wt/wt, 2.9 % wt/wt, 3.0 % wt/wt, 3.1% wt/wt, 3.2% wt/wt, 3.3% wt/wt, 3.4% wt/wt, 3.5% wt/wt, 3.6% wt/wt, 3.7 % wt/wt, 3.8% wt/wt, 3.9% wt/wt, 4.0% wt/wt, 4.1% wt/wt, 4.2% wt/wt, 4.3% wt/wt, 4.4% wt/wt, 4.5% wt/wt, 4.6% wt/wt, 4.7% wt/wt, 4.8% wt/wt, 4.9% wt/wt, 5.0% wt/wt, 5.1% wt/wt, 5.2% wt/wt, 5.3% wt/wt, 5.4% wt/wt, 5.5% wt/wt, 5.6% wt/wt, 5.7% wt/wt, 5.8% wt/wt, 5.9% wt/wt, 6.0% wt/wt, 6.1% wt/wt, 6.2% wt/wt, 6.3% wt/wt, 6.4% wt/wt, 6.5% wt/wt, 6.6% wt/wt, 6.7% wt/wt, 6.8% wt/wt, 6.9% wt/wt, 7.0% wt/wt, 7.1% wt/wt, 7.2% wt/wt, 7.3% wt/wt, 7.4% wt/wt, 7.5% wt/wt, 7.6% wt/wt, 7.7% wt/wt, 7.8% wt/wt, 7.9% wt/wt, 8.0% wt/wt, 8.1% wt/wt, 8.2% wt/wt, 8.3% wt/wt, 8.4% wt/wt, 8.5% wt/wt, 8.6% wt/wt, 8.7% wt/wt, 8.8% wt/wt, 8.9% wt/wt, 9.0% wt/wt, 9.1% wt/wt, 9.2% wt/wt, 9.3% wt/wt, 9.4% wt/wt, 9.5% wt/wt, 9.6% wt/wt, 9.7% wt/wt, 9.8% wt/wt, 9.9% wt/wt, 10.00% wt/wt, 10.1% wt/wt, 10.2% wt/wt, 10.3% wt/wt, 10.4% wt/wt, 10.5% wt/wt, 10.6% wt/wt, 10.7% wt/wt, 10.8% wt/wt, 10.9% wt/wt, 11.0% wt/wt, 11.1% wt/wt, 11.2% wt/wt, 11.3% wt/wt, 11.4% wt/wt, 11.5% wt/wt, 11.6% wt/wt, 11.7% wt/wt, 11.8% wt/wt, 11.9% wt/wt, 12.0% wt/wt, 12.1% wt/wt, 12.2% wt/wt, 12.3% wt/wt, 12.4% wt/wt, 12.5% wt/wt, 12.6% wt/wt, 12.7% wt/wt, 12.8% wt/wt, 12.9% wt/wt, 13.0% wt/wt, 13.1% wt/wt, 13.2% wt/wt, 13.3% wt/wt, 13.4% wt/wt, 13.5% wt/wt, 13.6% wt/wt, 13.7% wt/wt, 13.8% wt/wt, 13.9% wt/wt, 14.0% wt/wt, 14.1% wt/wt, 14.2% wt/wt, 14.3% wt/wt, 14.4% wt/wt, 14.5% wt/wt, 14.6% wt/wt, 14.7% wt/wt, 14.8% wt/wt, 14.9% wt/wt and 15.0% wt/wt.

In an embodiment, the one or more polyethylene glycol having a molecular weight of about 500-800 is selected from one or more of the groups consisting of PEG570, PEG600, and PEG700.

In an embodiment the total amount of the one or more polyethylene glycol having a molecular weight of about 500-800 is about 0.5-5.0 % wt/wt of the total formulations, such as about 0.5 % wt/wt, 0.6 % wt/wt, 0.7 % wt/wt, 0.8 % wt/wt, 0.9 % wt/wt, 1.0 % wt/wt, 1.1 % wt/wt, 1.2 % wt/wt, 1.3 % wt/wt, 1.4 % wt/wt, 1.5 % wt/wt, 1.6 % wt/wt, 1.7 % wt/wt, 1.8 % wt/wt, 1.9 % wt/wt, 2.0 % wt/wt, 2.1 % wt/wt, 2.2 % wt/wt, 2.3 % wt/wt, 2.4 % wt/wt, 2.5 % wt/wt, 2.6 % wt/wt, 2.7 % wt/wt, 2.8 % wt/wt, 2.9 % wt/wt, 3.0 % wt/wt, 3.1% wt/wt, 3.2% wt/wt, 3.3% wt/wt, 3.4% wt/wt, 3.5% wt/wt, 3.6% wt/wt, 3.7 % wt/wt, 3.8% wt/wt, 3.9% wt/wt, 4.0% wt/wt, 4.1% wt/wt, 4.2% wt/wt, 4.3% wt/wt, 4.4% wt/wt, 4.5% wt/wt, 4.6% wt/wt, 4.7% wt/wt, 4.8% wt/wt, 4.9% wt/wt and 5.0% wt/wt.

In an embodiment the one or more bio adhesive is selected from one or more of the group consisting of polyvinylpyrrolidone (PVP, e.g. Povidone K25^®), acacia powder, corn starch, chitosan and derivative thereof, sodium alginate, polycarbophils, hydroxy ethyl cellulose, guar gum, gum karaya, carboxymethyl cellulose, hydroxy propyl methyl cellulose (and other non-ionic polymer bio adhesives), and carbomers (i.e., polymers of acrylic acid) but may also include any material which allows the formulation to adhere to the surface of a biological tissue, such as the mucin layer of a mucosal tissue, for an extended period of time.

In an embodiment the one or more bio adhesive is about 2.0-6.0 % wt/wt of the total formulations, such as about 2.0 % wt/wt, 2.1 % wt/wt, 2.2 % wt/wt, 2.3 % wt/wt, 2.4 % wt/wt, 2.5 % wt/wt, 2.6 % wt/wt, 2.7 % wt/wt, 2.8 % wt/wt, 2.9 % wt/wt, 3.0 % wt/wt, 3.1 % wt/wt, 3.2 % wt/wt, 3.3 % wt/wt, 3.4 % wt/wt, 3.5 % wt/wt, 3.6 % wt/wt, 3.7 % wt/wt, 3.8 % wt/wt, 3.9 % wt/wt, 4.0 % wt/wt, 4.1 % wt/wt, 4.2 % wt/wt, 4.3 % wt/wt, 4.4 % wt/wt, 4.5 % wt/wt, 4.6 % wt/wt, 4.7 % wt/wt, 4.8 % wt/wt, 4.9 % wt/wt, 5.0 % wt/wt, 5.1 % wt/wt, 5.2 % wt/wt, 5.3 % wt/wt, 5.4 % wt/wt, 5.5 % wt/wt, 5.6 % wt/wt, 5.7 % wt/wt, 5.8 % wt/wt, 5.9 % wt/wt and 6.0 % wt/wt.

In an embodiment, the one or more lubricant is selected from one or more of the group consisting of stearic acid, magnesium stearate, calcium stearate, zinc stearate, talc, polyethylene glycol, sodium benzoate, sodium n-dodecyl sulphate, mineral oil and polyoxyethylene monostearate. In a preferred embodiment, the one or more lubricant is magnesium stearate.

In an embodiment the one or more lubricant is present in an amount of about 1.0-4.0 % wt/wt of the total formulations, such as about 1.0 % wt/wt, 1.1 % wt/wt, 1.2 % wt/wt, 1.3 % wt/wt, 1.4 % wt/wt, 1.5 % wt/wt, 1.6 % wt/wt, 1.7 % wt/wt, 1.8 % wt/wt, 1.9 % wt/wt, 2.0 % wt/wt, 2.1 % wt/wt, 2.2 % wt/wt, 2.3 % wt/wt, 2.4 % wt/wt, 2.5 % wt/wt, 2.6 % wt/wt, 2.7 % wt/wt, 2.8 % wt/wt, 2.9 % wt/wt, 3.0 % wt/wt, 3.1 % wt/wt, 3.2 % wt/wt, 3.3 % wt/wt, 3.4 % wt/wt, 3.5 % wt/wt, 3.6 % wt/wt, 3.7 % wt/wt, 3.8 % wt/wt, 3.9 % wt/wt, and 4.0 % wt/wt.

In an embodiment the one or more disintegrating agent is selected from one or more of the group consisting of i) natural starches, such as maize starch, potato starch, and the like, directly compressible starches, e. g. Sta-rx^® 1500, modified starches, e.g. carboxymethyl starches and sodium starch glycolate, available as Primojel^®, Explotab^® and Exp lo sol^®, and starch derivatives, such as amylose; (ii) crosslinked sodium carboxymethyl cellulose (croscarmellose sodium), e.g. Ac-di-sol^®, Primellose^®, Pharmacel^® XL, Explocel^® and Nymcel^® ZSX; (iii) alginic acid and alginates, e.g. sodium alginate; (iv) methacrylic acid- divinylbenzene copolymer salts, e.g. Amberlite^® IRP-88; (v) polymers of vinylpyrrolidone, e.g. crosslinked polyvinylpyrrolidones, such as crospovidones, Polyplasdone^® XL and Kollidon^® CL; and (vi) magnesium aluminium silicate and bentonite. In a preferred embodiment, the one or more disintegrating agent is starch.

In an embodiment the one or more disintegrating agent is about 7.0-12.0 % wt/wt of the total formulations, such as 7.1 % wt/wt, 7.2 % wt/wt, 7.3 % wt/wt, 7.4 % wt/wt, 7.5 % wt/wt, 7.6 % wt/wt, 7.7 % wt/wt, 7.8 % wt/wt, 7.9 % wt/wt, 8.0 % wt/wt, 8.1 % wt/wt, 8.2 % wt/wt, 8.3 % wt/wt, 8.4 % wt/wt, 8.5 % wt/wt, 8.6 % wt/wt, 8.7 % wt/wt, 8.8 % wt/wt, 8.9 % wt/wt, 9.0 % wt/wt, 9.1 % wt/wt, 9.2 % wt/wt, 9.3 % wt/wt, 9.4 % wt/wt, 9.5 % wt/wt, 9.6 % wt/wt, 9.7 % wt/wt, 9.8 % wt/wt, 9.9 % wt/wt, 10.0 % wt/wt, 10.1 % wt/wt, 10.2 % wt/wt, 10.3 % wt/wt, 10.4 % wt/wt, 10.5 % wt/wt, 10.6 % wt/wt, 10.7 % wt/wt, 10.8 % wt/wt, 10.9 % wt/wt, 11.0 % wt/wt, 11.1 % wt/wt, 11.2 % wt/wt, 11.3 % wt/wt, 11.4 % wt/wt, 11.5 % wt/wt, 11.6 % wt/wt, 11.7 % wt/wt, 11.8 % wt/wt, 11.9 % wt/wt and 12.0 % wt/wt.

In another aspect, the invention provides methods for preparing a dry powder formulation of Vitamin D, or a salt derivative or metabolite thereof, in the form of a direct compression tablet. Therefore, the formulations described herein may be prepared by direct compression tabletting techniques.

In another aspect, the invention provides a method of preparing a formulation comprising Vitamin D, or a salt, derivative or metabolite thereof, said method including the steps of: a) dissolving the Vitamin D, or a salt, derivative or metabolite thereof in a quantity of one or more polyethylene glycols having a molecular weight of about 500-800; and b) melting a quantity of one or more polyethylene glycols having a molecular weight of about 1000-4000 and adding the resultant melt to the mixture obtained from a). In an embodiment, the formulation has a friability of below about 0.5%, such as below about 0.4%, 0.3% or 0.2%. In an embodiment, the friability of the formulation is about 0.1%. These friability values enable packaging in any kind of package using conventional machinery which means that special care need not be taken in the intermediate bulk storage of the tablets (or other dry compressed forms).

In an embodiment, the formulation is characterised with hardness of about 2-5 KP, for instance, about 2 KP, about 3 KP, about 4 KP or about 5 KP.

In an embodiment, the formulation is characterised with an oral disintegration time of less than about 2 minutes, such as less than 1 minute 40 second, less than 1 minute 30 seconds, less than 1 minute 20 seconds, less than 1 minute 10 seconds, less than 1 minutes, less than 50 seconds, less than 40 seconds, less than 30 seconds, less than 20 seconds, less than 10 seconds, once the formulation comes into contact with saliva in the oral cavity.

The rapid disintegration times means that the formulation (for instance, in the form of a tablet) can be administered without the need for water. It is also postulated that the formulation may also serve to deliver quantities of the active by absorption through the buccal mucosal lining. This would be an advantage as it relates to direct systemic delivery such that the active bypasses the stomach and first pass metabolism of the liver.

It is proposed that the present formulations are useful in the improvement in bone health of CKD patients. The use of sublingual administration by way of the present formulations may improve compliance in dosing strategies and adequacy of overall vitamin D status, particularly in those populations at high risk for vitamin D insufficiency and suboptimal bone health such as in patients with CKD.

Sublingual (or buccal) delivery is where a drug is administered through the mucosal membranes lining the cheeks (buccal mucosa). The buccal mucosa is an area of the oral cavity that is richly vascularized and more accessible for the administration and removal of a dosage form. Deficiency of, and resistance to, vitamin D, are common in CKD and thus constitute a major part of the skeletal consequences of chronic uraemia. Calcitriol and VDRAs are effective in managing SHPT however concerns about adverse effects of hypercalcemia and potential exacerbating vascular calcification limit their widespread use. Despite its weaker effect on PTH suppression than calcitriol or VDRAs, nutritional vitamin D is also associated with fewer adverse effects of hypercalcemia and hyperphosphatasemia. Treatment with sublingual vitamin D at earlier stages of CKD may prevent renal, cardiac and skeletal complications associated with CKD. Calcifediol, a vitamin D3 analogue, offers the opportunity to safely and effectively manage SHPT in CKD patients, increasing 25(OH)D levels and lowering PTH (more effectively than nutritional vitamin D and without the toxicity of calcitriol/VDRAs), and potentially improve BMD to significantly reduce fracture risk in this population.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", are understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

NON-LIMITING EXAMPLES

Example 1 - Formulation 1

Example 2 - Formulation 2

Method of Manufacturing for Formulation 2:

1. Dissolve vitamin D3 into PEG 600.

2. Melt PEG 1500 at 45°C and add into the above step.

3. Cool down the mixture up to 25°C and pass through 40 mesh s.s Screen.

4. Triturate the above material with lactose and pass through 30 mesh s.s screen.

5. Sieve the remaining excipients i.e., Sorbitol Powder, starch and povidone via 20 mesh screen and mix with the above step 4. For 15 minutes.

6. Add magnesium stearate in step 5 and mix for 5 minutes and compress the tablet. Example 3 - Formulation 3

Example 4- Formulation 4

Example 5 - Formulation 5

i Weigh 51 mg/tab

ii Friability 0.1%

iii Hardness 2 - 3 KP

iv Disintegration 30 seconds

Example 6 - Formulation 6

Characterisation of tablets:

Hardness (N):

This is determined in a Schleuniger 6D durometer using the resistance to crushing method set forth in en Ph. Eur. 2.9.8. The average value range of the determinations are detailed.

Friability (%):

This is determined in a Pharma test friability tester using the method set forth in Ph. Eur. 2.9.7. Example 7: Formulation No.7 (without antioxidant)

s # In redient Qh/Tal) ( ing) Role of Inured ien 1

1 Vitamin D3 * 0.029 Active

2 PEG 600 2.5 Surface active agent

3 PEG 1500 2.5 Penetration enhancer

4 Sorbitol powder 44.271 Sweetener

5 Acacia 0.3 Bio adhesive

6 Starch 0.3 Disintegrating agent

7 Mg. Stearate 0.1 Lubricant

Total 50

Manufacturing Method:

1. Accurately weigh PEG 600 and PEG 1500 in a glass beaker & melt them in water bath/hot plate above at 80 °C and maintain the temperature. Add vitamin D3 in molten wax and dissolve for 5 minutes with continuous stirring.

2. The system is then put into freezer at - 2 °C for 2 hrs

3. Crush the freeze mass and ground gently with sorbitol powder with the help mortar and pestle and pass through 20 mesh ss screen.

4. Triturate the above material with Sorbitol powder with the help of mortar and pestle.

5. Add other excipients and blend them for five minutes.

6. Compress the tablets according to the following specification:

Targeted Specifications are i Weight 50 mg/Tablet

ii Friability Less then 1 %

iv Disintegration Less then 2 minutes Example 8: Formulation No.8 (with antioxidant) s # Ingredient Qty/TalX nig) Role of Ingredient

1 Vitamin D3 * 0.029 Active

2 PEG 600 2.5 Surface active agent

3 PEG 1500 2.5 Penetration enhancer

Butylated Antioxidant

Hydroxytoluene

4 (BHT) 0.1

5 Sorbitol powder 43.806 Sweetener

6 Acacia 0.3 Bio adhesive

7 Starch 0.3 Disintegrating agent

8 Silicon Dioxide 0.1 Glidden

9 Sodium Ascorbate 0.365 Antioxidant

Total 50

Method of Manufacturing:

1. Weigh PEG - 1500 and PEG - 600 accurately in a glass beaker at 80 °C and maintain temperature for 5 minutes now add BHT and dissolve in the molten wax.

2. Heat under nitrogen cover

3. Add Cholecalciferol and dissolve for 20 minutes.

4. Cool down the wax and add silicon dioxide and mix.

5. Triturate the step 4 with sorbitol powder and other excipients.

6. Add other excipients and blend them for five minutes.

7. Compress the tablets according to the following specification:

Targeted Specifications are

In the above examples Vitamin D3 refers to cholecalciferol. Example 9 Clinical Study for assessing the efficacy of sublingual Vitamin D formulation to improve bone health in Chronic Kidney Disease (CKD).

Rationale:

This randomized controlled trial (RCT) of vitamin D in CKD addresses whether vitamin D (and particularly sublingual vitamin D) affects clinical health outcomes in this patient population. Applicant proposes an RCT of vitamin in CKD to assess bone health is justified because the large potential benefits and cost savings that may be achieved.

Current treatment of SHPT in patients with CKD has significant limitations, especially with regard to the potential for increased calcification risk. Newer therapy with calcifediol has been demonstrated in CKD patients with SHPT to improve biochemical parameters of low 25(0 H) D and high PTH levels and may improve bone health without the increased risk of hypercalcemia and concern about adverse cardiovascular health.

Hypothesis:

Vitamin D deficiency in patients with CKD contributes to SHPT and subsequent low BMD and increased fracture risk, and the use of calcifediol to better manage SHPT will improve bone health in this population. Compliance and the bioavailability of calcifediol is improved by the use of sublingual formulations.

Aim:

To assess the efficacy of sublingual calcifediol in patients with CKD stages 3b - 5 to improve SHPT and subsequently improve BMD as determined by DXA.

Study Design:

This study is a double-blinded, placebo-controlled, parallel-arm study, over 24 months with 1: 1 randomization of participants to calcifediol or matched placebo daily. Participants are stratified according to age, gender and CKD stage.

Inclusion criteria:

1. CKD stages 3b-5 (eGFR <45ml/min/1.72m²)

2. Age 50 years

3. SHPT (PTH above the upper limit of the normal range)

4. Serum calcium level <2.60mmol/L Exclusion criteria:

1. Transplantation or dialysis (or anticipated requirement for dialysis or transplant in the next 12 months)

2. Recent hospitalization for acute illness (within last month)

3. Allergy to calcifediol

4. Current use of bisphospho nates

5. Current use of glucocorticoids

6. Primary hyperparathyroidism

7. History of previous or anticipated parathyroidectomy

8. Pregnancy

9. Life expectancy less than two years as judged by primary physician Primary outcome:

Change in hip and femoral neck BMD (as measured by DXA) after 24 months (0 and 24 months).

Secondary outcomes:

1. Biochemical parameters: Local laboratory - calcium, phosphate, magnesium, albumin, alkaline phosphatase (ALP), PTH, bicarbonate, 25(OH)D (0, 6, 12, 18, 24 months); Central laboratory - l,25(OH)2D, FGF23, klotho, sclerostin, BMP-7, bone-specific ALP, vitamin D binding protein (0, 12, 24 months)

2. Lumbar and distal radius BMD, determined by DXA (0, 24 months)

3. Trabecular bone score (TBS), determined by DXA (0, 24 months) in a random sample where the DXA software is available for this measurement

4. Renal parameters: serum creatinine, eGFR, progression of CKD to ESKD, change in proteinuria (urinary albumin: creatinine ratio) (0, 12, 24 months)

5. Cardiovascular parameters: clinic blood pressure, vascular calcification (aortic calcification determined by lateral DXA image, 0, 24 months)

6. Bone turnover markers: Central laboratory - P1NP (procollagen type 1 N propeptide), TRAPSb (tartrate-resistant acid phosphatase 5b) (0, 12, 24 months)

7. Markers of anaemia: haemoglobin (Hb), iron (Fe) stores, erythropoietin resistance index (ERI) if receiving erythropoiesis-stimulating agent (ESA) (0, 12, 24 months)

8. 24-hour urinary calcium and phosphate excretion (0, 12, 24 months) on a random sample of participants 9. Health-related quality of life assessment (SF36 questionnaire) (0, 12, 24 months)

10, Bone pain symptom score (0, 12, 24 months)

11. Muscle strength assessment (hand- grip strength and 6-minute walk test) (0,

12, 24 months)

12. Medication changes: phosphate-lowering agents, calcium or nutritional vitamin D supplementation, calcitriol or VDRAs, bisphospho nates

13. Adverse events: hypercalcemia, study medication side effects, medication suspension or cessation

14. Other outcomes: fracture, cardiovascular, events, hospitalisations, parathyroidectomy, mortality

Procedures:

DXA

BMD are measured at baseline and 24 months using DXA. DXA scans of the lumbar spine (L1-L4, both antero -posterior [AP] and lateral images), left total hip (including femoral neck) and left ultra-distal radius are conducted at local sites.

Study medication:

Calcifediol or matched placebo will be administered sublingually (absorbed via the buccal mucosa). The active medication contains calcifediol (1000 IU, equivalent to 25mcg of calcidiol) formulated according to the present invention for sublingual administration. Participants will take one tablet daily (total 25mcg/day) and the dose are titrated to 50mcg daily if PTH levels remain elevated above the normal range. These tablets are <10mm circular tablets with a disintegration time less than 2 minutes.

There is known variations in the bioavailability of nutritional vitamin D (cholecalciferol) capsules when swallowed. It is known that liquid versions of the drug are absorbed more easily than powdered capsules or cholecalciferol administered as a tablet. The use of the sublingual formulations having polyethylene glycols as disclosed herein with calcifediol in this study will avoid problems with first-pass metabolism and potentially help lower the amount of drug having to be administered to the patient to achieve a similar increase in serum 25(OH)D.

During the study if participants develop PTH levels persistently abnormally low or serum calcium levels consistently above the normal range, study medication are suspended. Study medication are recommenced when the serum laboratory values have normalized.

Study participants on calcium or nutritional vitamin D supplementation at randomization will have these medications ceased. Should treating clinicians wish to recommence either of these medications at any stage during the 24-month study period, no more than a maximum dose of two tablets daily of either (calcium carbonate 1000-1200mg daily or cholecalciferol 2000 units daily) should be administered.

Data linkage:

All patients will provide a Medicare number for future linkage to hospitalisations records and the death registry, and linkage to ANZDATA will also enable future assessment of patients who develop ESKD requiring dialysis or transplantation. This linkage will enable future determination of hospitalized fractures, parathyroidectomy rates and overall survival outcomes in the study patient cohort beyond the 24-month study period

Statistical Analysis

Predicted baseline hip BMD 1.0+/-0.3 g/cm² in both groups with an expected +5,0 (+/1) % increase after 24 months in the calcifediol group and an expected -5.0 (+/-1) % decrease in those on placebo.

A difference of 0.102g/cm² lower femoral neck BMD in patients with CKD is associated with increased fracture as reported in a recent systematic review assessing BMD and fracture risk in the CKD population.⁷⁸

A sample size of 368 participants is required for 90% power to detect this difference. The aim is to recruit 442 patients to allow 10% loss to follow-up per year.

Example 10 - Expanded Clinical Study for assessing the efficacy of sublingual Vitamin D formulation to improve bone health in Chronic Kidney Disease (CKD).

AIMS AND HYPOTHESIS

Primary aim: To test the hypothesis that vitamin D therapy with calcifediol in patients with CKD stages 3-4 will result in significant improvement in bone mineral density (BMD) as measured by dual- energy x-ray absorptiometry (DXA).

Secondary aims: To test the hypotheses that calcifediol treatment of patients with CKD stages 3-4:

a. results in reduction in serum parathyroid hormone (PTH) concentration;

b. has no influence on levels of calcium and phosphate, or increases risk of hypercalcemia;

c. results in reduction in markers of bone remodeling;

d. improves quality of life; and

e. is cost-effective.

BACKGROUND AND RATIONALE

Abnormalities of mineral metabolism in CKD are a major problem: CKD (estimated glomerular filtration rate [eGFR] <60mL/min/1.73 m and/or proteinuria for at least 3 months) is a major public health problem affecting between 11.5% and 13.4% of Australian adults (equivalent to 1.4-1.6 million individuals). CKD is associated with increased risks of cardiovascular and all-cause mortality. The excess cardiovascular disease burden and mortality in CKD is largely due to the presence of 'non- traditional' risk-factors, and has been associated with hyperparathyroidism, hyperphosphatasemia, and arterial medial calcification, which are highly prevalent in CKD patients. CKD is complicated by a systemic disorder known as Chronic Kidney Disease - Mineral and Bone Disorder (CKD-MBD), which includes (i) abnormal homeostasis of calcium, phosphate, 1,25-dihydroxycholecalciferol (l,25[OH]2D3), PTH and fibroblast growth factor 23 (FGF23); (ii) disturbances in bone volume, remodeling, mineralization and linear growth, including a heightened risk of fracture; (iii) extra- skeletal calcification in arteries and soft tissues leading to cardiovascular disease; and (iv) other systemic manifestations.

Vitamin D insufficiency and deficiency and secondary hyperparathyroidism (SHPT) are common in CKD: Serum PTH levels are increased in many CKD patients, even with modest decreases in GFR. SHPT affects 40% and 82% of patients with CKD stages 3 and 4 respectively. SHPT is associated with greater risks of osteitis fibrosa, fractures, bone pain and mortality. Hypertrophy and hyperplasia of parathyroid glands progresses with worsening renal function leading to a state of treatment-resistant hyperparathyroidism (also known as tertiary hyperparathyroidism) necessitating parathyroidectomy.

Vitamin D deficiency (25[OH]D level <25 nmol/L) or insufficiency (25-50 nmol/L) is common in CKD with only 15-30% patients with CKD stages 3 to 5 having sufficient levels greater than 75 nmol/L. Lower levels of 25(OH)D are related to decreased sunlight exposure, nutritional deficiency, loss of vitamin D binding protein in the urine, decreased hepatic synthesis of 25(OH)D and increased catabolism of 25(OH)D to 24,25(OH)2D. Low 25(OH)D levels are associated with increased risks of mortality, rapid decline of kidney function, and lower bone formation rate and trabecular mineralization surface with increased fractures in CKD patients.

Bone disease and fracture risk in CKD are a maior problem: CKD-MBD is characterized by disturbances in bone modelling and remodeling. These abnormalities include impaired bone turnover and mineralization and deterioration in microarchitecture, loss of bone mass, cortical thinning, increased cortical porosity, trabecular thinning, perforation and disintegration. These abnormalities affect the majority of patients with CKD stages 3-5, worsening with declining kidney function. CKD-MBD adversely affects bone strength, a composite of bone quantity and quality and is associated with high risk of fractures. Hip fractures are common across the spectrum of CKD and are associated with additional hospitalisations, excess morbidity and mortality.

The risk of fracture is 4-14 times higher in patients on dialysis relative to individuals without kidney disease, and fracture incidence is similar to individuals 10-15 years older in the general population. This excess risk also extends to pre-dialysis CKD patients, where an cGFR 15- 60ml/min per 1 .7 rrr may confer a 1.5-3 times greater risk of fracture compared to the non-CKD population. In a Canadian cohort of 679,114 adults, the 3-year cumulative incidence of fractures of the hip, forearm, pelvis, or proximal humerus in eGFR groups of 45-59, 30-44, 15-29, and <15m!/min per 1 .73ητ were 5.8%, 6.5%, 7.8%, and 9.6%, respectively.

Assessment of fracture prediction in CKD: Complexity of bone abnormalities, the potential unreliability of available serum bio markers of bone and mineral metabolism, and the infrequent use of bone biopsy in CKD patients pose substantial challenges to the diagnosis and management of renal bone disease. DXA in CKD predicts fracture risk: In the general population, BMD measurement by DXA is a strong predictor of fracture risk. The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) CKD-MBD Clinical Guidelines recommended DXA to assess fracture risk in patients with CKD stages 1-3, but not in CKD stages 4-5 given the lack of definitive data at that time. More recent prospective studies have reported significant associations between DXA BMD and fracture risk in CKD 3-5 patients. In a study involving 2,754 well- functioning community-living older individuals with CKD (83%, 13% and 3% with CKD stages 3a, 3b and 4 respectively) and without CKD (mean eGFR

72.7ml/min/1.73m ), 10% were found to have BMD T-scores < -2.5; consistent with osteoporosis. Over 11 years, 17% and 11% of individuals from the CKD and non-CKD groups respectively, suffered a non-spine fragility fracture. Low femoral neck BMD was associated with increased risk of fracture (HR for each SD lower BMD: CKD group 2.74, 95%CI 1.99-3.77; non- CKD group 2.15, 95%CI 1.80-2.57). In a study involving 131 patients with CKD stage 3-5, those with incident fractures had lower baseline hip BMD than those without fractures (0.77 g/cm², 95%CI 0.73-0.80 vs. 0.95 g/cm², 95%CI 0.92- 0.98). Further, the annual decrease in BMD in patients with fractures was greater than those without fractures (2.6%, 95%CI 1.6-3.7 vs. 1.2%, 95%CI 0.6- 1.7). Therefore, the revised 2017 KDIGO CKD-MBD Clinical Guidelines recommend DXA to assess fracture risk in all stages of CKD.

High-resolution imaging of bone can assess microarchitecture: DXA lacks the ability to determine bone micro structure and therefore bone strength. High-resolution peripheral quantitative computed tomography (HR-pQCT) and high-resolution magnetic resonance imaging (HR-MRI or micro-MRI) provide accurate noninvasive quantification of bone microarchitecture and facilitate assessment of bone geometry, correlating with skeletal fragility. Finite element analysis (FEA) can be applied to three-dimensional HR-pQCT and micro-MRI data to measure strength either of whole bone or its compartments. Most research in high-resolution imaging of bone has focused on populations without CKD, and very few imaging studies have targeted the added complexities of bone pathology unique to the CKD population. HR-pQCT and micro-MRI, in conjunction with accurate and appropriate bone turnover markers, can potentially be used to assess fracture risk, although further research is needed to validate these tools in the CKD population. PTH and vitamin D are associated with BMD: SHPT is an important mediator of cortical bone loss in patients with CKD, and PTH is an independent predictor of BMD. Two longitudinal studies reported high serum PTH levels were associated with greater decrease in BMD over time. In addition, there is a significant positive relationship between serum 25(OH)D levels and BMD in the general population. There has been reported a positive relationship between serum 25(OH)D and BMD in dialysis patients. There has also been reported a similar relationship between serum 25(OH)D levels and BMD in patients with CKD stage 5, 85% of whom were on dialysis.

Data relating to vitamin D treatment to improve fracture risk/BMD: Meta-analysis of cholecalciferol (700-800 IU/day) in ambulating and institutionalized subjects reported reduced risk of hip or any nonvertebral fractures, and calcitriol monotherapy may slow the rate of bone loss but at increased risk of hypercalcemia.

Problems with current treatment of SHPT in CKD: 'Active' vitamin D therapy, either as calcitriol or a vitamin D analogue (VDRA, such as paricalcitol, doxercalciferol and alfacalcidol), is the most often used treatment for SHPT in CKD. These agents act via the vitamin D receptor (VDR) on parathyroid glands exerting a direct effect on PTH secretion by inhibition of its mRNA synthesis. Despite the potent PTH-lowering effect of calcitriol/VRDAs, the potential benefit of vitamin D therapy in CKD remains unproven. A meta-analysis of 76 trials showed that vitamin D compounds did not reduce the risk for death, bone pain or vascular calcification. Skeletal effects of vitamin D compounds have not been systematically studied. These agents, when compared with placebo, increased the risk of hypercalcemia, with a potential for worsening of vascular calcification. The KDIGO CKD-MBD Work Group have recently revised clinical guidelines to state that "calcitriol and VRDAs should not be routinely used in patients with CKD stages 3-5 not on dialysis (evidence level 2C). Instead it is reasonable to reserve these agents for only severe and progressive SHPT (evidence not graded). The Guidelines suggest that patients with PTH levels progressively rising or persistently above the upper normal limit for the assay be evaluated for modifiable factors, such as vitamin D deficiency. 'Nutritional' vitamin D (cholecalciferol and ergocalciferol) corrects vitamin D deficiency in CKD patients, but is ineffective as a treatment of SHPT with advancing renal impairment. On the other hand, 'active' vitamin D (calcitriol or VRDAs) has a potent PTH- lowering effect, but does not correct serum 25(OH)D levels. Moreover, calcitriol and VRDAs are not subject to physiologic feedback regulation; as a result, these agents can cause toxicity, and also accelerate vitamin D catabolism by inducing CYP24A1 (25-hydroxylase) and FGF23 leading to exacerbation of vitamin D deficiency. Therefore, a novel treatment that (a) reduces bone loss, pain and fracture rates; (b) corrects vitamin D deficiency; and (c) does not cause hypercalcemia, would be an ideal treatment of CKD-MBD.

Calcifediol is a useful treatment for SHPT: Calcifediol (25[OH]D) is a prohormone of the active form of vitamin D3 that is converted to calcitriol by CYP27B1 (la- hydroxylase) primarily in the kidney. Since calcifediol requires la- hydro xylation for activation, it remains under physiologic feedback regulation and does not cause over- suppression of PTH and hypercalcemia. In a placebo- controlled randomized trial of patients with CKD stages 3 and 4 (n=78), modified-release calcifediol (30, 60 or 90 μg daily over 6 weeks) had minimal effect on CYP24Aland FGF23. Significantly more participants in the calcifediol group achieved serum 25(OH)D levels >75 nmol/L than the placebo group (90% vs. 3%) with only one instance of hypercalcemia (>2.62 mmol/L) in a subject in the 60 μg group. Percent reduction in PTH in the 30, 60 and 90 μg groups were 21, 33 and 39%, respectively. In another placebo-controlled randomized trial of patients with CKD stages 3 and 4 (n=429) assessing modified-release calcifediol (30 μg daily over 26 weeks), 81% and 7% participants in the calcifediol and placebo groups achieved serum 25(OH)D levels >75 nmol/L with only one instance of hypercalcemia (>2.57 mmol/L) in a subject in the calcifediol group. Significantly more participants in the calcifediol group achieved >30% reduction in PTH levels (34% vs. 7%). Applicant proposes calcifediol is a safe and effective treatment for vitamin D deficiency and SHPT in pre-dialysis CKD patients without any major toxicity. Therefore, calcifediol is an attractive agent to study effects on bone loss, pain and fracture risk in CKD.

Summary: CKD-MBD is a highly prevalent systemic disorder even in non-dialysis CKD patients, characterized by SHPT and a huge burden of bone and cardiovascular disease. Effective treatment in earlier stages of CKD has potential to prevent severe complications in later CKD stages. Currently used vitamin D compounds are limited by their inability to simultaneously correct both SHPT and vitamin D deficiency, and adverse effects of hypercalcemia and potential treatment-resistance. Evidence for using any therapeutic intervention to reduce the bone loss and fractures in CKD is lacking. Consequently, most CKD patients continue to suffer from bone pain, fractures and associated morbidity and mortality. Calcifediol is a novel medication that can both correct SHPT and vitamin D deficiency in CKD without the risk of hypercalcemia. It holds promise for improving bone strength and reducing fracture risk. An adequately powered randomized trial is required to demonstrate the effects of calcifediol on the quantitative and qualitative markers of bone strength, and patient-reported outcomes such as bone pain and quality of life.

RESEARCH PLAN

The trial is an investigator-initiated, international, multi-centre, double-blind, randomized, placebo-controlled phase 3 trial (see Figure 1 for study schema).

Study design: Prospective randomized double-blind placebo-controlled trial

Setting: Nephrology Departments in teaching hospitals

Study population

To be eligible to participate in this trial, patients need to satisfy ALL of these inclusion criteria:

1. CKD stages 3-4 (eGFR 15-60 ml/min/1.72m²)

2. Age > 18 years

3. SHPT (PTH above the upper limit of the normal range)

4. 25(OH)D level <50 nmol/L (within 12 months prior to enrolment)

5. Serum calcium level <2.60 mmol/L

6. Able to provide informed consent

In addition, potential participants must have NONE of the following exclusion criteria:

1. Kidney transplant

2. Anticipated requirement for transplantation or dialysis in the next 12 months

3. Recent hospitalisations for acute illness (within last month)

4. Allergy to calcifediol

5. Current use of bisphosphonates; and/or current use of glucocorticoids

6. Primary hyperparathyroidism

7. History of previous or anticipated parathyroidectomy

8. Life expectancy less than two years as judged by primary physician

Justification of the study population:

Disorders of mineral metabolism (including SHPT and vitamin D deficiency) are not only highly prevalent in the CKD population, but also associated with poor clinical outcomes. To achieve maximum impact to reduce fracture burden, treatments targeting bone health need to be instituted early in the CKD-MBD trajectory. Therefore, the choice of eGFR between 15 and 60 mL/min/1.73m in this study is the ideal stage of CKD, and targeting patients with SHPT and vitamin D insufficiency will involve individuals at increased risk of bone disease and fracture.

Study interventions

Experimental intervention: Participants in the experimental arm will receive calcifediol 1000 IU daily (equivalent to 25mcg of calcidiol), developed using the sublingual formulations subject the present invention (absorbed via the buccal mucosa). These tablets are <10mm circular tablets with a disintegration time less than 2 minutes.

Calcifediol is a novel vitamin D prohormone demonstrated to correct low serum 25(OH)D and improve SHPT. In one randomized controlled trial of 429 patients with CKD stages 3-4, 72% of participants had at least a 10% reduction of PTH levels after 12 months, with no significant impact on calcium, phosphate or FGF23 levels. Calcifediol is a safe and effective treatment for SHPT without the increased calcification risk of calcitriol/VDRAs.

Justification of the experimental intervention: There are known variations in the bioavailability of nutritional vitamin D (cholecalciferol) capsules when swallowed. Liquid versions of the drug are absorbed more easily than powdered capsules or cholecalciferol tablets. The use of sublingual administration with calcifediol according to the formulations described herein in this study will avoid problems with first-pass metabolism and potentially help lower the amount of drug to be administered to achieve a similar increase in serum 25(OH)D. Adherence to daily vitamin D therapy is an important factor influencing vitamin D status, and compliance with therapies for bone health is a major challenge. Despite the potential for improved functional ability and independence, adherence to osteoporosis medications (e.g. bisphosphonates, vitamin D and calcium) is only 50-70%, and falls further to 25-35% beyond the first year. The use of other forms of administration such as a sublingual mode, need to be explored for improved adherence to dosing strategies and adequacy of overall vitamin D status, particularly in high risk populations such as patients with CKD. Table 1. Differences between vitamin D therapies for managing SHPT in moderate to advanced CKD

Control intervention: Participants in this arm will receive matched placebo.

Justification of the control intervention: Currently there is insufficient evidence to recommend widespread use of nutritional vitamin D supplementation in vitamin D deficient/insufficient CKD patients. The 2017 KDIGO CKD-MBD Guidelines removed the previous suggestion of treatment of vitamin D deficiency due to the absence of evidence. Hence, use of placebo in this trial is justified. Dose of the study medication: All participants will be asked to take one tablet of study medication once daily. The dose of the study medication will not be titrated against serum levels of vitamin D, PTH, or calcium due to (i) the absence of evidence; (ii) modest PTH elevations may be an appropriate adaptive response to declining kidney function; and (iii) titrating study medication will threaten trial blinding. If a participant develops hypercalcemia (serum calcium >2.61 mmol/L) on at least two occasions 4 weeks apart, study medication will be suspended. Study medication will be recommenced after normalization of serum calcium levels.

Concurrent management

All participants will receive appropriate management of CKD-related issues as per the current standard of care at the treating centre. The use of calcium (maximum dose 500- 600mg/day) and/or cholecalciferol (maximum dose lOOOunits/day) will be permitted. Since calcitriol and VDRAs are not subject to physiologic feedback regulation, their use will not be permitted.

Blinding: Participants, investigators and outcome assessors will be blinded to the treatment allocation.

Outcomes Measures

Primary outcome measure:

The primary outcome measure of this study is femoral neck BMD. Left femoral neck BMD will be measured by DXA at baseline and 24 months at local study sites. BMD assessment by DXA has good reproducibility (<l-2% coefficient of variation), reliable reference ranges for age, gender and race, and can predict fracture risk in patients with CKD. DXA is an inexpensive, widely available technique that can be easily standardised across sites. Given this reliability, DXA is a good tool in longitudinal CKD research studies for serial assessment of BMD in response to interventions.

Secondary outcome measures:

1. PTH levels: Venous blood samples will be collected at specified study periods as described in Table 2. The proportion of participants who have varying degrees of SHPT will be compared between study groups.

2. BMD: DXA images of the total hip, lumbar spine (L1-L4, both antero-posterior [AP] and lateral images) and non-dominant ultra-distal radius will also be performed.

3. Bone turnover markers (BTMs): Bone-specific alkaline phosphatase (bsALP), fasting procollagen type 1 N propeptide (P1NP) and tartrate-resistant acid phosphatase 5b (TRAP5b) will be measured at baseline and 12-monthly. bsALP and P1NP are markers of bone formation and TRAP5b is a marker of resorptive activity. Studies correlating these BTMs with BMD, as well as the prospective prediction of fractures, in CKD patients are lacking. There is a potential role for a combination of biomarkers such as BTMs in association with imaging for better fracture prediction in CKD.

4. Incident fractures (any site). Vertebral fracture assessment (VFA) will also be determined on lateral vertebral DXA image (reported centrally).

5. Renal function: Serum creatinine (eGFR), progression of CKD to dialysis, and change in proteinuria will be recorded.

6. Health-related quality of life: Assessment of quality of life (using the SF36 questionnaire) as well as a bone pain symptom score and muscle strength assessment (hand-grip strength and 6-minute walk test) will be performed 12- monthly. 7. Other outcomes: Medication changes, side effects of study medication, hospitalisations, parathyroidectomy, and mortality will be recorded.

Exploratory outcome measure:

Bone microarchitecture: High-resolution imaging at the radius and distal tibia will be performed at baseline and 24 months using (a) high-resolution peripheral quantitative computed tomography (HR- pQCT) in a sample of participants (n=50, using Scanco HR- pQCT and Strax analysis) and (b) high-resolution magnetic resonance imaging (HR-MRI or micro-MRI) in a second sample of participants (n=50).

Sample Size Calculation

Assuming a baseline femoral neck BMD 1.0+0.3 g/cm , an expected +2.5+1% in the calcifediol group and an expected -2.5+1% decrease in the placebo group over 24 months, correlation of r=0.7 between baseline and 24-month BMD, and loss to follow-up 10%, 430 participants per arm or 860 participants in total will have 90% power to demonstrate a difference of 0.05g/cm in femoral neck BMD. This difference is associated with increased fracture risk in CKD, and thus clinically meaningful. No provision has been made for drop-ins (administration of calcifediol to patients in placebo arm of the study) given calcifediol is not available in Australia, New Zealand or Malaysia.

Assessment of participants: Study visits are scheduled as described in Table 2.

Table 2. The Trial-CKD Study visit schedule

Assessment Baselin Visits 24- e month

(End of study)

History, consent

Concomitant medications, adverse events 6 monthly

DXA (femoral neck, total hip, radius, spine) 24-monthly

Ca, P, PTH, ALP, Mg, albumin, 25(OH)D, 6-monthly

bicarbonate

l,25(OH)2D3, FGF23, bsALP and other 12-monthly

BTMs, sex hormones

eGFR, uACR 12-monthly

SF-36, bone pain score, muscle strength testing 12-monthly

HR-pQCT (n=50), micro-MRI (n=50) 24-monthly Abbreviations: Ca, calcium; P, phosphate; ALP, alkaline phosphatase; Mg, magnesium; bsALP, bone-specific ALP; BTMs, bone turnover markers; uACR, urinary albumin/creatinine ratio

Analysis

Statistical analysis: The treatment effect will be estimated by comparing the end of the study values of the outcome measures (taken at 24 months), using analysis of covariance (ANCOVA) to adjust for their baseline values. Subgroup analyses will be performed according to the stages of CKD, age groups, gender and administration of nutritional vitamin D. Differences in other continuous variables between the calcifediol and placebo groups will be analysed by ANCOVA adjusting for baseline measurements. Categorical variables will be analysed using the chi-square test with frequencies and percentages per treatment arm.

Economic analysis: A trial based economic evaluation will be conducted to determine the incremental costs and health outcomes of vitamin D therapy in maintaining BMD. A healthcare funder perspective will be used; costs will include all intervention costs, all health care resource use over the trial duration, and outpatient resource use (MBS and PBS costs). Quality adjusted life years (QALYs), will be calculated using the SF-36 via the SF6D. Both costs and health will be discounted at 5%. An incremental cost per additional patient achieving a clinically meaningful improvement in femoral neck BMD, and incremental cost per QALY gained in the vitamin D group, compared to control group will be calculated with results plotted on a cost-effectiveness plane. One-way and multi- way sensitivity analysis will be conducted around key variables. A cost- effectiveness acceptability curve will be plotted to provide information about the probability that the intervention is cost- effective, given willingness to pay for each additional health outcome achieved.

OUTCOMES AND SIGNIFICANCE

CKD is a growing major public health problem in Australia and worldwide. CKD-MBD, a highly prevalent systemic disorder is characterized by vitamin D deficiency, SHPT, arterial medial calcification, left ventricular hypertrophy, bone loss, bone pain and high fracture rates. As a result, among all chronic diseases, the combined burden of cardiovascular disease, skeletal complications, inferior survival and poor quality of life is largest among CKD patients. There is very little clinical research however investigating novel therapeutic agents for CKD-related complications, including CKD-MBD. The absence of specific evidence-based guidelines on the management of CKD-MBD among non-dialysis CKD patients is highlighted by the 2017 revised KDIGO CKD-MBD Guidelines Working Group. The currently available therapeutic armamentarium to treat vitamin D deficiency and SHPT is limited to nutritional vitamin D, calcitriol and VDRAs. These agents are only partially effective and associated with complications. Data on their effects on patient- related skeletal outcomes, such as bone strength and quality, bone pain and fractures are currently lacking. Adequately powered, high quality, randomized placebo-controlled trials are required to evaluate the benefits and risks of novel agents to improve bone strength and quality. Calcifediol, a prohormone of the active form vitamin D3, effectively corrects vitamin D deficiency and lowers serum PTH levels without causing hypercalcemia in CKD. There is now a sufficient body of clinical evidence to justify a randomized trial evaluating the effects of calcifediol on the quantitative and qualitative markers of bone strength, and patient-reported outcomes. Demonstration of a significant improvement in bone strength will provide clinicians with an important, effective and safe treatment to reduce the burden of skeletal complications and disability suffered by patients with CKD.

Claims

CLAIMS:

1. A formulation comprising:

(i) Vitamin D, or a salt, derivative or metabolite thereof;

(ii) one or more polyethylene glycols having a molecular weight of about 1000- 4000; and

(iii) one or more polyethylene glycols having a molecular weight of about 500- 800.

2. The formulation of claim 1 comprising one or more bio adhesive agents selected from the group consisting of polyvinylpyrrolidone, carbomers, acacia powder, guar gum, gum karaya, hydroxypropylcellulose, hydroxypropylmethylcellulose, polycarbophils, corn starch, chitosan and derivative thereof, and sodium alginate.

3. The formulation of any one of claims 1 to 3 comprising:

(i) one or more lubricants; and/or

(ii) one or more disintegrating agents; and/or

(iii) one or more binding agents; and/or

(iv) one or more taste masking agents.

4. The formulation of claim 1 or claim 2 in the form of a direct compression tablet.

5. The formulation of any one of claims 1 to 4 wherein the Vitamin D is a metabolite.

6. The formulation of claim 5 wherein the metabolite is cholecalciferol (Vitamin D3), calcifediol or calcitriol.

7. The formulation of claim 5 wherein the metabolite is calcifediol.

8. The formulation of claim 7, wherein the calcifediol is present in an amount of between about 500 IU and about 1500 IU, or between about 600 IU and about 1400 IU, or between about 700 IU and about 1300 IU, or between about 800 IU and about 1200 IU, or between about 900 IU and about 1100 IU, or about 1000 IU.

8. The formulation of any one of claims 1 to 7, wherein the disintegration time is less than about 3 minutes, or less than about 2 minutes or less than about 1 minute.

9. A method of treating or preventing a condition associated with a deficiency in or resistance to Vitamin D or a derivative or a metabolite thereof, the method comprising the step of administering to a subject in need thereof the formulation of any one of claims 1 to 8.

10. The method of claim 9 wherein the condition associated with a deficiency in or resistance to Vitamin D, or a derivative or a metabolite thereof is a bone mineralisation disorder or a bone remodelling disorder, or a mineral metabolism disorder.

11. The method of claim 9 wherein the condition associated with a deficiency in or resistance to Vitamin D, or a derivative or a metabolite thereof is secondary hyperparathyroidism.

12. The method of any one of claims 9 to 11 wherein the formulation is disposed in and retained in the buccal cavity or sublingual region thereof until most or substantially all of the formulation disintegrates.

13. The method of claim 12 wherein the disintegration time is less than about 3 minutes, or less than about 2 minutes or less than about 1 minute.

14. The method of any one of claims 9 to 13 wherein the Vitamin D, or a derivative or a metabolite thereof is selected from the group consisting of cholecalciferol, calcifediol and calcitriol.

15. The method of any one of claims 9 to 13 wherein the Vitamin D, or a derivative or a metabolite thereof is calcifediol.

16. The method of claim 15 wherein the calcifediol administered to the subject at a rate of between about 500 IU and about 1500 IU, or between about 600 IU and about 1400 IU, or between about 700 IU and about 1300 IU, or between about 800 IU and about 1200 IU, or between about 900 IU and about 1100 IU, or about 1000 IU per day.

17. The method of one of claims 9 to 16 wherein the formulation is administered at a maximum rate of once per day.

18. A method of preparing a formulation according to claims any one of claims 1 to 8 comprising Vitamin D, or a salt, derivative or metabolite thereof, said method including the steps of: a) dissolving the Vitamin D, or a salt, derivative or metabolite thereof in a quantity of one or more polyethylene glycols having a molecular weight of about 500-800; and b) melting a quantity of one or more polyethylene glycols having a molecular weight of about 1000-4000 and adding the resultant melt to the mixture obtained from a).