Insmed Inc, a biopharmaceutical company, announced results from its exploratory US phase-II clinical trial evaluating Iplex (mecasermin rinfabate) in patients with myotonic muscular dystrophy (MMD). The randomized, double-blind, placebo-controlled phase-II trial conducted in 13 centres across the US enrolled 69 patients with MMD, for a six-month period. As this was an exploratory trial, a primary endpoint was not pre-defined. The trial explored measures of endurance, using the six-minute walk test, muscle function and strength, cognitive function, gastrointestinal function, pain, quality of life, insulin sensitivity, lipid metabolism, and safety and tolerability of Iplex.

The results of the trial indicated that Iplex did not exhibit a statistically significant improvement in the functional measure of endurance by the six-minute walk test, muscle function, muscle strength, or quality of life in any of the tests utilized in this study. Based on the limited number of subjects enrolled with significant impairments in cognitive function, gastrointestinal function or pain, Insmed was unable to reach any conclusions regarding the effects of Iplex on these endpoints.

Iplex did, however, demonstrate improvements in standard measures of insulin sensitivity and reductions in fasting glucose, fasting insulin, cholesterol and triglycerides, which is consistent with the expected metabolic profile of insulin-like growth factor. Administration of Iplex also resulted in anabolic effects of increased body mass index and higher levels of testosterone. The drug was well tolerated in MMD subjects and demonstrated a safety profile consistent with previous studies of Iplex.

Based on the metabolic improvements observed in patients treated with Iplex in this trial, and discussions with key opinion leaders, the company intends to apply for a grant from the Muscular Dystrophy Association (MDA) to facilitate an additional phase-II trial focused solely on a subset of MMD patients with severe insulin resistance who, based on the results of this trial, may be more likely to benefit from Iplex treatment. Alternative methods of assessing muscle function will be considered for the proposed trial.

Dr Melvin Sharoky, Insmed's chairman, commented, "We are disappointed that this trial did not meet the majority of its functional endpoints. However, the statistically significant improvement in insulin sensitivity seen in this study suggests that an additional phase-II study in MMD patients with severe insulin resistance may be warranted. We appreciate the MDA's financial support for the completed trial and look forward to the possibility of continuing to work with them."

Sharon Hesterlee, senior vice president and executive director of MDA Venture Philanthropy, said, "While the phase-II clinical trial of Iplex did not show efficacy in the overall MMD population in this trial, based on the data generated, we look forward to evaluating Insmed's grant application for a possible phase-II trial aimed at MMD patients with severe insulin resistance."

Dr Sharoky continued, "Iplex continues to demonstrate a strong safety profile and we believe it offers a potential treatment in multiple therapeutic areas, including Amyotrophic Lateral Sclerosis. Beyond Iplex, our current cash reserves of approximately $120 million provides us with a significant opportunity to continue growing our business through a variety of potential business development initiatives. We look forward to continuing to explore these possibilities with our strategic financial advisor, RBC Capital Markets."

Insmed is a biopharmaceutical company with unique protein development experience and a proprietary protein platform aimed at niche markets with unmet medical needs.