Andrew Wolff
Analyst · H.C. Wainwright
Thanks Fady. As you know during the quarter, we reported data from the first Phase II study of reldesemtiv in adolescent and adult patients with SMA. We believe that this hypothesis generating its primary objective to determine potential pharmacodynamic effect of reldesemtiv after multiple oral doses in patients with SMA as well as secondary objectives to evaluate the safety, tolerability, and pharmacokinetics of reldesemtiv. As you also know, we're developing reldesemtiv in collaboration with Astellas as a potential treatment for people with SMA and other debilitating diseases and conditions associated with skeletal muscle weakness and/or fatigue. The study showed dose in concentration-dependent increases and changes from baseline in six-minute walk distance, a sub maximal exercise test of aerobic capacity and endurance, and maximal expiratory pressure or MEP, a measure of strength of certain respiratory muscles after eight weeks of treatment with reldesemtiv. Other assessments in the study including the Hammersmith functional motor score extended, revised upper limb module, timed up and go, and forced vital capacity did not demonstrate meaningful differences between reldesemtiv versus placebo. Since reporting the data from the study, we've had the opportunity to discuss them with our investigators and key opinion leaders as well as analysts and investors. I'd like to provide additional context and perspective on interpreting the clinical meaningfulness of the data and review potential next steps in the development program for reldesemtiv. I will then provide updates on the other ongoing mid-stage clinical trials of reldesemtiv in patients with ALS, COPD, and frailty. I'd first like to address a question relating to the Hammersmith scale which is an endpoint we assessed in this study and has been used in other studies. The Hammersmith scale is the endpoint for which nusinersen or SPINRAZA was approved. It is a key measure to assess developmental milestones in infants and children. It is an appropriate endpoint that has been demonstrated to be useful in assessing the therapeutic effects of SMN-directed therapies. However, because the Hammersmith scale is directed primarily to evaluating early developmental milestones in infants and small children, it is rarely used clinically in older patients. It is a test of maneuverability more than a test of fatigability and therefore, it is not viewed by many expert SMA clinicians as a useful assessment in the adolescent and adult population of SMA patients living with muscle weakness. We included this assessment in our study because we wanted to test any functional and respiratory measures that could be relevant to this population. That said, as we saw in the study and as we continue to learn in clinical practice, it is not a commonly used assessment in the older patient population. For another measure, six-minute walk distance, we saw about a 25-meter increase with the high dose of reldesemtiv with statistically significant dose dependence. Similar magnitudes of effect have been observed following administration of enzyme replacement therapies as well as with treatment for pulmonary hypertension leading to approvals of novel therapies for diseases of significant unmet medical need. We're very encouraged by the observed effects of reldesemtiv on six-minute walk distance in this study. Furthermore, data from our study support the evaluation of higher doses with reldesemtiv in potential future clinical trials in SMA for three reasons; first, because no efficacy plateau was demonstrated; second, because no dose limiting safety or tolerability issues were observed; and third, because the exposures we achieved at the higher dose in the study were only about half what we expected based on a prior study of reldesemtiv in healthy subjects. In that study, those higher exposures were also well-tolerated and associated with increased pharmacodynamic effect relative to the lower exposures. To adolescents and adults in our study had a baseline six-minute walk distance of between 250 and 300 meters and they are generally living functional lives. For them a 25-meter or 10% increase in six-minute walk distance may enable them to perform activities of daily living with less fatigue. Things like walking more readily through an airport, raking leaves, or simply feeling more confident in leg strength to step on or off a curb. These could be important improvements for these patients and experts have advised that six-minute walk distance is the most viable assessment for an ambulatory SMA population. It's important to remember that while the advent of gene-directed therapies will no doubt transform the course of SMA disease progression, patients treated with these therapies still have residual muscle dysfunction, weakness, and early fatigability. Our expectation is that as these babies with SMA survive into later childhood, adolescence, and adulthood, there may be as many as 5,000 to 10,000 ambulatory SMA patients just in the United States alone living longer with their disease, but still with muscle dysfunction and weakness. Therefore, a skeletal muscle activator like reldesemtiv may prove to be an effective complement to SMN-directed therapies. In terms of next steps, we're still discussing the data with our partner Astellas and have not yet had the opportunity to review these data with regulatory authorities. We will continue to seek regulatory and expert guidance together with Astellas to chart a course for a potential Phase III program on a timeline hopefully to be agreed later this year. Moving, now to the other mid-stage trials of reldesemtiv; FORTITUDE-ALS, our Phase II clinical trial of reldesemtiv in patients with ALS continues to recruit with more than half our target enrollment completed. Last quarter, we indicated we were adding sites in Australia and Europe to increase enrollment and some of these sites are now open and screening patients. Enrollment has been slower than we experienced in our recent Phase III study of tirasemtiv in patients with ALS -- VITALITY-ALS. We believe this may be related to the availability and uptake of edaravone in the U.S. as evidenced by enrollment rates approaching historical averages in Canada where edaravone is not yet available. We've worked hard to increase the enrollment rate in the U.S. over the last two quarters. However, it has remained steady despite our efforts. Therefore, we now anticipate we will complete enrollment in the fourth quarter of this year and expect to report results from this trial in the first half of 2019. Moving to the non-neuromuscular trials, Astellas completed enrollment in the Phase II clinical trial of reldesemtiv in patients with COPD and we expect to report data in this third quarter. In addition, Astellas will conduct an interim analysis of data from the ongoing Phase Ib study of reldesemtiv in elderly adults with limited mobility or frailty also in this third quarter of 2018. And now, I will turn the call over to Pete to provide an update on our financials.