Cytokinetics, Inc. today announced that the second cohort of the Phase 2 clinical trial of CK-2127107 in patients with spinal muscular atrophy (SMA), is open to enrollment. This clinical trial is designed to assess the effect of CK-2127107, a next-generation fast skeletal troponin activator (FSTA), on multiple measures of muscle function in both ambulatory and non-ambulatory patients with SMA.
The decision to proceed to Cohort 2 follows a review of safety and pharmacokinetics data from Cohort 1 by the Data Monitoring Committee (DMC). In collaboration with Astellas (TSE:4503) (“Astellas”), Cytokinetics is developing CK-2127107 as a potential treatment for people living with SMA and certain other debilitating diseases and conditions associated with skeletal muscle weakness and/or fatigue.
“We are pleased to advance this clinical trial to the next phase of execution and appreciate the enthusiasm of our investigators to explore the potential of this novel mechanism drug candidate that specifically targets skeletal muscle and potentially improves muscle force, function and stamina,” said Fady I. Malik, MD, PhD, Cytokinetics’ Executive Vice President, Research and Development.
Clinical Trial Design
The primary objective of this Phase 2 hypothesis-generating, double-blind, randomized, placebo-controlled clinical trial is to determine the potential pharmacodynamic effects of a suspension formulation of CK- 2127107 following multiple oral doses in patients with Type II, Type III, or Type IV SMA. Secondary objectives are to evaluate the safety, tolerability and pharmacokinetics of CK-2127107. There is no single primary endpoint in this trial.
The trial is designed to enroll 18 ambulatory (Type III or Type IV) and 18 non-ambulatory (Type II or Type III) patients 12 years of age and older in Cohort 1, randomized 2:1 to receive 150 mg of CK-2127107 or placebo, stratified by ambulatory versus non-ambulatory status, dosed twice daily for eight weeks. The second cohort of patients will receive 450 mg of CK-2127107 dosed twice daily, also for eight weeks.
As in Cohort 1, multiple assessments of skeletal muscle function and fatigability will be performed including respiratory assessments, upper limb strength and functionality for non-ambulatory patients, as well as six-minute walk and timed-up-and-go for ambulatory patients. Additional information can be found at www.clinicaltrials.gov.
Cure SMA Funding for Combination Therapies
The clinical trials for CK-2127107 came about because of early seed funding from Cure SMA, supporting research focused on the potential application of these types of skeletal muscle activators to SMA. In 2014, Cytokinetics released encouraging data from preclinical studies conducted with our funding. The data showed this approach had positive effects in preserving muscle strength and reducing muscle fatigue, setting the groundwork for the ongoing clinical trials.
The progress of this program also highlights the importance of developing combination therapies to treat SMA. The goal is that CK-2127107 will show positive results in preserving muscle strength in human clinical trials, and may lend itself to combination with other SMA therapies, particularly those that address the SMN protein deficiency caused by the SMN1 mutation.