17 June 2022 - - US-based biopharmaceutical company Sierra Oncology, Inc. (NASDAQ: SRRA) has submitted a New Drug Application to the US Food and Drug Administration for momelotinib, an ACVR1 / ALK2, JAK1 and JAK2 inhibitor in development for the treatment of myelofibrosis, the company said.

The NDA submission is based on the results from several Phase 2 and Phase 3 studies, including the recently completed MOMENTUM study.

As with all new drug applications, the company expects the FDA to respond as to whether this submission is accepted within 60 days.

Assuming the submission is accepted and a subsequent approval is granted, commercial launch of momelotinib is anticipated in 2023.

MOMENTUM is a global, randomized, double-blind Phase 3 clinical trial of momelotinib versus danazol in patients with myelofibrosis who were symptomatic and anemic, and had been previously treated with an FDA-approved JAK inhibitor.

The study was designed to evaluate the safety and efficacy of momelotinib for the treatment and reduction of the key hallmarks of disease: symptoms, blood transfusions (due to anemia) and splenomegaly (enlarged spleen).

Results from the MOMENTUM study were presented at the 2022 annual meeting of the American Society of Clinical Oncology.

The primary endpoint of the study is Total Symptom Score reduction of >50% over the 28 days immediately prior to the end of Week 24 compared to baseline TSS, using the Myelofibrosis Symptom Assessment form (MFSAF).

Secondary endpoints included Transfusion Independence rate for >12 weeks immediately prior to the end of Week 24 with Hgb levels ≥ 8 g/dL, and Splenic Response Rate based on splenic volume reduction of >35% at Week 24.

The study enrolled 195 patients based on a planned 180 patients across 21 countries.

Danazol was selected as the treatment comparator given its use to ameliorate anemia in patients with myelofibrosis, as recommended by National Comprehensive Cancer Network and European Society of Medical Oncology guidelines.

Patients were randomized 2: 1 (MMB n = 130 and DAN n = 65) to receive either momelotinib or danazol. After 24 weeks of treatment, patients on danazol were allowed to crossover to receive momelotinib.

Early cross-over to momelotinib was available for confirmed symptomatic splenic progression.

Momelotinib is a potent, selective and orally bioavailable ACVR1 / ALK2, JAK1, JAK2 inhibitor under investigation for the treatment of myelofibrosis in symptomatic, anemic patients previously treated with an approved JAK inhibitor.

More than 1,200 subjects have received momelotinib since clinical studies began in 2009, including approximately 1,000 patients treated for myelofibrosis, several of whom remain on treatment for over 12 years.

Momelotinib is the first and only JAK inhibitor to demonstrate positive data for all key hallmarks of the disease--symptoms, splenic response and anemia.

Myelofibrosis is a rare blood cancer that results from dysregulated JAK-STAT signaling and is characterized by constitutional symptoms, splenomegaly (enlarged spleen) and progressive anemia.

From prior studies with momelotinib, we know approximately half of myelofibrosis patients are moderately to severely anemic when eligible for JAK inhibitor treatment.

Furthermore, currently approved JAK inhibitors only address symptoms and splenomegaly and are myelosuppressive.

This can lead to worsening anemia, resulting in dose reductions that potentially reduce treatment effect.

Sierra Oncology is a late-stage biopharmaceutical company on a mission to deliver targeted therapies that treat rare forms of cancer.