Syntara Limited (ASX:SNT), a clinical-stage drug development company, is pleased to announce top-line data from the Phase 2a clinical trial evaluating amsulostat (200 mg BID) in combination with ruxolitinib (RUX) for the treatment of myelofibrosis (MF). The open-label study evaluated the safety and efficacy of amsulostat over 52 weeks. Patients with intermediate-2 or high-risk MF had been treated with RUX for an average of three years with symptom scores, spleen sizes and blood counts indicative of high disease burden.
16 patients were enrolled into the study. 11 patients reached 24 weeks, 8 patients reached 38 weeks and 7 patients completed the full 52 weeks of treatment. The patient withdrawal rate is consistent with that seen in other MF studies of patients with similar disease severity.
Highlights:
- The safety and tolerability of amsulostat, now shown out to 52 weeks, together with the increasing size and durability of clinical benefit seen beyond 24 weeks compares very favourably with other drugs in development.
- Improvements of 50% or more in total symptom score (TSS50) were observed quickly (as early as 12 weeks) and were sustained, with 73% (8/11) of patients achieving TSS50 at Week 24 or beyond. The 2 patients that reached 52 weeks (in addition to the 5 reported at EHA) achieved a complete (100%) resolution of symptoms from baseline.
- Meaningful spleen volume reductions (SVR) were observed at 24 weeks and maintained thereafter, with 44% (4/9) of patients achieving SVR25 at Week 24 or beyond. Of the 2 patients that reached 52 weeks (in addition to the 5 reported at EHA) one patient retained SVR25 at Week 52.
- Of the 7 patients who completed 52 weeks of treatment, 6 chose to continue on amsulostat through named patient supply. 3 of these patients had a minor anaemia response. These numbers are consistent with meaningful benefit to patients.
- Of the 6 patients with efficacy data who withdrew early from the study, 3 achieved TSS50 at their last visit. Of these 6 patients, 3 were evaluable for spleen volume, and all demonstrated reductions, with one achieving 61% SVR at 38 weeks.
- The positive results allow for the next stage of amsulostat clinical development and partnership engagement, supported by appointments of global strategic, clinical and commercial advisors also announced today.
Syntara CEO Gary Phillips commented: “I’m delighted with these results. We recruited a group of patients who had already been extensively treated with the current best standard of care and yet still had enlarged spleens and significant symptoms. In this difficult to treat, sub-optimally controlled cohort, amsulostat emerges with a very competitive and well differentiated profile that holds real hope for patients. The safety and tolerability profile, combined with sustained improvements in both symptom burden and spleen volume out to 52-weeks, underscore the potential of this novel therapy. The results of the study will help define the patient population and treatment duration of future studies and we look forward to engaging with regulators and potential partners on the pathway forward.”
