Momelotinib Wins Canadian Approval for Myelofibrosis With Anemia

Momelotinib in myelofibrosis

Health Canada has approved momelotinib (Ojjaara) for the treatment of splenomegaly and/or disease-related symptoms in adult patients with intermediate- or high-risk primary myelofibrosis, post–polycythemia vera or essential thrombocythemia myelofibrosis who have moderate-to-severe anemia.¹

This regulatory decision was supported by findings from the pivotal phase 3 global, multicenter, randomized, double-blind MOMENTUM trial (NCT04173494), which compared momelotinib (n = 130) with danazol (Danocrine; n = 65) in patients with myelofibrosis who were anemic, symptomatic, and had prior exposure to an approved JAK inhibitor.

In total, 25% of patients in the momelotinib arm reported a total symptom score (TSS) reduction of at least 50% vs 9% of those in the danazol arm (proportion difference, 16%; 95% CI, 6%-26%; P < .01).² Furthermore, 30% of patients who received momelotinib achieved transfusion independence between weeks 12 and 24 vs 20% of those who received danazol (noninferiority treatment difference, 14%; 95% CI, 2%-25%; P = .023). Overall, 35% and 17% of patients in the momelotinib and danazol arms, respectively, required no transfusions during the 24-week treatment period (treatment difference, 17%; 95% CI, 8%-26%; P = .001).

Spleen volume reduction (SVR) of at least 25% was reported in 39% and 6% of patients in the momelotinib and danazol arms, respectively (treatment difference, 33%; 95% CI, 23%-44%; P < .0001). SVR of at least 35% (SVR35) was observed in 22% and 3% of these respective populations (treatment difference, 18%; 95% CI, 10%-27%; P = .001). Moreover, the Myelofibrosis Symptom Assessment Form 4.0 TSS change from baseline was –9.4 in the momelotinib arm vs –3.1 in the danazol arm (treatment difference, –6.2; 95% CI, –10 to –2.4).

“Treatment options for myelofibrosis-related anemia have been limited. We are proud to offer this treatment alternative for Canadian patients to address this critical unmet need and other myelofibrosis symptoms,” Michelle Horn, interim country medical director of GSK Canada, stated in a news release.¹ “With most [patients with] myelofibrosis becoming anemic over time, [momelotinib’s] approval represents a significant milestone to improve the outcomes of these patients while also highlighting GSK’s commitment to making an impact in Canada’s hematology oncology space through innovative new treatments.”

Additional support for this regulatory decision came from data from a subset of patients with moderate to severe anemia at baseline in the phase 3, multicenter, randomized, double-blind SIMPLIFY-1 trial (NCT01969838), which compared momelotinib (n = 215) with ruxolitinib (Jakafi; n = 217) in patients with myelofibrosis who had not previously received a JAK inhibitor.² In total, 31.4% (95% CI, 21.8%-42.3%) of patients in the momelotinib arm achieved SVR35 vs 32.6% (95% CI, 23.4%-43.0%) of those in the ruxolitinib arm. Notably, the percentage of patients treated with momelotinib who reported a TSS score reduction of at least 50% at week 24 was numerically lower than that of patients treated with ruxolitinib, at 25% vs 36%.

“Anemia and related transfusions significantly affect the quality of life, prognosis, and survival for anemic [patients with] myelofibrosis,” Cheryl Petruk, chief executive officer of HEAL Canada, added in the news release.¹ “We are excited to witness progress in this rare disease space and to see [momelotinib] approved in Canada. This new treatment has the potential to help improve the lives of patients while addressing the disease’s main challenges, namely anemia and other major symptoms.”

In 2023, the FDA approved momelotinib for the treatment of adult patients with intermediate- or high-risk myelofibrosis, including primary or secondary myelofibrosis, and anemia based on findings from the MOMENTUM and SIMPLIFY-1 trials.³

References

1. Ojjaara (momelotinib) approved in Canada for the treatment of myelofibrosis in adults who have moderate to severe anemia. News release. GSK. November 12, 2024. Accessed November 13, 2024. https://ca.gsk.com/en-ca/media/press-releases/ojjaara-momelotinib-approved-in-canada-for-the-treatment-of-myelofibrosis-in-adults-who-have-moderate-to-severe-anemia/
2. Momelotinib (Ojjaara) Prescribing information. GlaxoSmithKline; 2023. Accessed November 13, 2024. https://gskpro.com/content/dam/global/hcpportal/en_US/Prescribing_Information/Ojjaara/pdf/OJJAARA-PI-PIL.PDF
3. Ojaara (momelotinib) approved in the US as the first and only treatment indicated for myelofibrosis patients with anaemia. News release. GlaxoSmithKline. September 15, 2023. Accessed November 13, 2024. https://www.gsk.com/en-gb/media/press-releases/ojjaara-momelotinib-approved-in-the-us-as-the-first-and-only-treatment-indicated-for-myelofibrosis-patients-with-anaemia