GSK’s New Drug Application (NDA) for momelotinib has been accepted by the US Food and Drug Administration (FDA) for patients who have myelofibrosis with anaemia.
The FDA is due to make a decision on momelotinib – which GSK maintains may address a ‘significant unmet need’ – by 16 June 2023. If accepted, the commercial launch of momelotinib is anticipated in 2023.
The NDA is based on results from key phase 3 trials, including the pivotal MOMENTUM trial – a global, randomised, double-blind phase 3 clinical trial of momelotinib versus danazol in patients with myelofibrosis who were symptomatic and anaemic and had been previously treated with an FDA-approved Janus kinase (JAK) inhibitor.
The study met all its primary and key secondary endpoints, demonstrating that momelotinib achieved a statistically significant and clinically meaningful benefit on symptoms, splenic response and anaemia.
Myelofibrosis is a rare blood cancer that results from dysregulated JAK-signal transducer and activator of transcription protein signalling affecting around 20,000 patients in the US, characterised by constitutional symptoms, splenomegaly and progressive anaemia.
Anaemia is the main reason why people with myelofibrosis discontinue treatment, with around 40% of patients already anaemic at the time of diagnosis and nearly all patients estimated to develop anaemia eventually.
Furthermore, currently approved JAK inhibitors only address symptoms and splenomegaly and are myelosuppressive, potentially leading to worsening anaemia and dose reductions that potentially reduce treatment effect.
Momelotinib is a JAK1/2 inhibitor, which treats symptoms of the cancer, but also targets other pathways called ACVR1 and IRAK1 that are thought to protect against anaemia.
Momelotinib was most recently developed by Sierra Oncology – a California-based, late-stage biopharmaceutical company focused on targeted therapies for the treatment of rare cancers – which GSK acquired in July 2022 in a deal worth £1.5bn.
Stephen Dilly, president and chief executive officer, Sierra Oncology, said at the time of the NDA submission: “Today is truly momentous for everyone at Sierra Oncology and the patients we serve. This team designed a targeted study to address the highest unmet need and delivered incredible results in the midst of a pandemic. We are thrilled to submit this NDA on behalf of myelofibrosis patients and look forward to working with the FDA over the coming months.”