Cytochroma has announced the positive results from the Phase 2b clinical trial of its drug product, CTAP101 capsules, used for the treatment of patients with secondary hyperparathyroidism (SHPT), stage 3 or 4 chronic kidney disease (CKD) and vitamin D insufficiency.

CTAP101 is a first-in-class treatment that is designed to reliably correct vitamin D insufficiency by increasing serum vitamin D pro-hormone (25D) concentrations to adequate levels and controlling elevated plasma intact parathyroid hormone (iPTH).

The Phase 2b study was a randomised, double-blind, placebo-controlled study that enrolled 78 subjects with SHPT, stage 3 or 4 CKD and vitamin D insufficiency across 17 sites in the US.

In the study, subjects were treated daily with one of three doses of CTAP101 capsules (30mcg, 60mcg, or 90mcg) or a matching placebo for six weeks and monitored for serum total 25-hydroxyvitamin D (25D), plasma iPTH and serum calcium and phosphorus levels.

"CTAP101 capsules performed well above the company’s expectations in the Phase 2b study."

CTAP101 capsules increased serum total 25D and reduced plasma iPTH by =30% from pre-treatment baseline in 39%, 65% and 63% of intent-to-treat subjects treated with doses of 30mcg, 60mcg and 90mcg, respectively.

Cytochroma president and CEO Charles Bishop said CTAP101 capsules performed well above the company’s expectations in the Phase 2b study.

"No marketed therapy both effectively controls elevated serum parathyroid hormone levels and corrects the underlying vitamin D insufficiency in CKD patients," Bishop added.

"These strong data indicate that CTAP101 capsules are a highly differentiated product compared to current treatment options. We look forward to initiating Phase 3 trials later in 2012."

CKD, a progressive loss in renal function, affects over 26 million people in the US, including more than eight million patients with moderate (stages 3 and 4) CKD, according to the National Kidney Foundation.

SHPT is a condition in which the parathyroid glands secrete excessive amounts of PTH into the blood due to renal and/or vitamin D insufficiency, leading to elevated serum calcium and phosphorus levels.