Andy Wolff
Analyst · Jason Butler from JMP Securities
Thank Fady, we've reviewed results from VITALITY-ALS back in November, so today, I'd like to reflect on our continuing analyses that may apply to our ongoing development program for reldesemtiv. As you know despite our actions to improve upon the tolerability challenges we observed in BENEFIT-ALS, by extending the open label lead in phase from one week to two weeks, and prolonging the dose titration steps in VITALITY-ALS, we unfortunately saw that the percentage of patients treated with tirasemtiv who discontinued double-blind treatment prematurely was still nearly three times higher than on placebo. Interestingly, in VITALITY-ALS, the rate of decline in slow vital capacity or SVC among the placebo patients was slower than what has been observed in previous trials including BENEFIT-ALS and power and those contributing to the database. Based on those trials, we expected the average decrease in SVC over 24 weeks to be approximately 16.2 percentage points. In VITALITY-ALS, SVC declined by 14.4 percentage points during 24 weeks on placebo. Less than expected and the smallest decline from baseline to 24 weeks observed in a recent major controlled clinical trial in patients with ALS. In addition, mortality at 48 weeks was less than half of what was observed in the Phase 3 and power trial of [indiscernible], the most recent large clinical trial in patients with ALS. These observations occurred despite the fact that baseline characteristics from these recent studies were similar to those in VITALITY-ALS. Whatever may underlie it, this apparent change in the rate of ALS disease progression in patients enrolled in VITALITY-ALS despite using typical inclusion criteria will need to be considered carefully as we plan for a potential phase 3 trial with reldesemtiv in 2019. Importantly, unlike BENEFIT-ALS, in which the primary analysis was essentially an on-treatment analysis, in VITALITY-ALS, we conducted an intent to treat analysis. In order to reduce the amount of missing data in the primary analysis, we focused on keeping patients in the trial whether or not they remained on double blind study drug. This contributed to our inability to demonstrate a clear benefit of tirasemtiv versus placebo because the primary efficacy analyses included many patients randomize to tirasemtiv who contributed an FCC measurement to the primary end point at 24 weeks despite having terminated treatments often months earlier. Despite all of this, the results presented at ALS MND in December as well as the results from several additional analyses that we have conducted reaffirm our belief that there was a biological effect observed in VITALITY-ALS which supports the continued development of reldesemtiv. Our ongoing analyses of VITALITY-ALS will inform our statistical analysis plan for FORTITUDE-ALS, and our experience conducting our first phase 3 clinical trial will surely inform the design of a potential next phase 3 trial for reldesemtiv in ALS. I also want to comment on the status of VIGOR-ALS, the open label extension clinical trial for patients who completed VITALITY-ALS. There are over 100 patients continuing treatment with tirasemtiv in this trial. And earlier this week, we convened an expert panel of ethicists, ALS patient advocates, clinicians, and other experts in pre-approval access to advise us regarding how best to continue to provide access to tirasemtiv for these patients. We plan to make a decision regarding continued access to tirasemtiv in the current quarter. Because we were aware of tolerability challenges with tirasemtiv early in its development, we designed a next generation fast skeletal muscle troponin activator is reldesemtiv from a distinct chemical scaffold to eliminate the off target effects and drug-drug interactions seen with tirasemtiv and to improve potency. As Fady will elaborate, we have demonstrated these intended improvements in recently published phase 1 studies in healthy volunteers. Moving to FORTITUDE-ALS, our ongoing phase 2 study of reldesemtiv in patients with ALS, site activation and enrollment activities are progressing well. We believe that FORTITUDE-ALS offers us the opportunity to test the therapeutic hypothesis of skeletal muscle activation in ALS without the confounding tolerability issues we face with tirasemtiv. In addition, in FORTITUDE-ALS, we have included novel functional measures of speech and handwriting and measurement of SVC at home. To date, 45 sites are activated, over 120 patients have been screened and nearly 90 have been enrolled. So we are well on our way to completing enrollment in the first half of 2018 with results expected in the second half of the year. During the first quarter, senior members of our team will visit essentially all the sites participating in FORTITUDE-ALS to engage our investigators, review with them the results from VITALITY-ALS, and remind them of the critical differences between reldesemtiv and tirasemtiv. In general, our investigators remain optimistic regarding the potential application of reldesemtiv in ALS, view FORTITUDE-ALS as one of the most important trials they are conducting, and don't foresee any issues enrolling FORTITUDE-ALS in the context of the result of VITALITY-ALS. Those that are enrolling patients have observed significantly better tolerability with reldesemtiv compared to tirasemtiv. We appreciate that our investigators continue to share a belief in the potential therapeutic benefit of fast skeletal muscle troponin activation in ALS and are grateful for their efforts to conduct FORTITUDE-ALS. We look forward to completing this clinical trial and reporting results before the end of the year. Now I’ll turn the call back over to Fady to provide additional updates on reldesemtiv as well as developments in research.