GSK plc (LON/NYSE:GSK) has announced that Japan’s Ministry of Health, Labour and Welfare (MHLW) has approved Omjjara (momelotinib) for the treatment of myelofibrosis. Omjjara is a once-a-day, oral JAK1/JAK2 and activin A receptor type 1 (ACVR1) inhibitor. The approval is based on data from the pivotal phase III MOMENTUM and SIMPLIFY-1 trials.
· Omjjara approved for use in both newly diagnosed or previously treated myelofibrosis patients
· Differentiated mechanism of action addresses key manifestations of myelofibrosis, namely anaemia, constitutional symptoms and splenomegaly
· In Japan, about 70% of patients diagnosed with primary myelofibrosis have moderate to severe anaemia at the time of diagnosis[1],[2],[3]
This is the fourth major regulatory approval for GSK’s momelotinib in the treatment of myelofibrosis, following approval under the brand name Ojjaara from the US Food and Drug Administration and authorisations under the brand name Omjjara from the European Commission and the Medicines and Healthcare products Regulatory Agency in the UK.
Nina Mojas, Senior Vice President, Oncology Global Product Strategy, GSK, said: “Myelofibrosis has a heavy disease burden, with symptomatic patients experiencing spleen enlargement, fatigue, night sweats and bone pain, along with anaemia which can lead to treatment discontinuation and dependence on regular blood transfusions. With the approval of Omjjara, myelofibrosis patients in Japan will have a new treatment option for this complex blood cancer.”
Myelofibrosis is a blood cancer that affects approximately 1 in 500,000 people worldwide, with up to 5,000 patients impacted in Japan.[4],[5],[6] In Japan, about 70% of patients diagnosed with primary myelofibrosis, and about half of those patients diagnosed with secondary myelofibrosis, have moderate to severe anaemia at the time of diagnosis.1,2,3 Nearly all patients are estimated to develop anaemia over the course of the disease.[7],[8],[9],[10] Myelofibrosis patients with anaemia require additional supportive care, including transfusions, and more than 30% will discontinue treatment with established therapies due to anaemia.[11] Patients who are anaemic and transfusion dependent have a poor prognosis and shortened survival.[12],[13],[14],[15],[16],[17],[18],[19],[20]
The approval is based on data from the MOMENTUM and SIMPLIFY-1 pivotal phase III trials. MOMENTUM was designed to evaluate the safety and efficacy of momelotinib versus danazol for the treatment and reduction of key manifestations of myelofibrosis in an anaemic, symptomatic, JAK inhibitor-experienced population. SIMPLIFY-1 was designed to evaluate the efficacy and safety of momelotinib versus ruxolitinib in myelofibrosis patients who had not received a prior JAK inhibitor therapy.
About Omjjara (momelotinib)
Momelotinib has a differentiated mechanism of action, with inhibitory ability along three key signalling pathways: Janus kinase (JAK) 1, JAK2, and activin A receptor, type I (ACVR1).1,[21],[22],[23] Inhibition of JAK1 and JAK2 may improve constitutional symptoms and splenomegaly.1,21,23 Additionally, inhibition of ACVR1 leads to a decrease in circulating hepcidin levels, potentially contributing to anaemia-related benefit.1,21,22,23
In September 2023, the US Food and Drug Administration licensed[24] momelotinib under the brand name Ojjaara for the treatment of intermediate or high-risk myelofibrosis, including primary myelofibrosis or secondary myelofibrosis (post-polycythaemia vera and post-essential thrombocythemia), in adults with anaemia.
In January 2024, the European Commission granted marketing authorisation[25] for Omjjara for disease-related splenomegaly (enlarged spleen) or symptoms in adult patients with moderate to severe anaemia who have primary myelofibrosis, post polycythaemia vera myelofibrosis or post essential thrombocythemia myelofibrosis and who are Janus kinase (JAK) inhibitor naïve or have been treated with ruxolitinib. Omjjara was also approved[26] by the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom to treat the symptoms experienced by adult myelofibrosis patients who have moderate or severe anaemia.
Please refer to the updated Product Information (PI) for precautions concerning indication and important dosage, administration, and safety information in Japan which will shortly be updated at this link: Japan Pharmaceuticals and Medical Devices Agency[27].
About myelofibrosis
Myelofibrosis is a rare blood cancer that disrupts the body’s normal production of blood cells because of dysregulated JAK-signal transducer and activator of transcription protein signalling. The clinical hallmarks of myelofibrosis are splenomegaly (enlarged spleen), severely low blood counts, including anaemia and thrombocytopenia, and debilitating constitutional symptoms, such as fatigue, night sweats and bone pain, attributable to ineffective haematopoiesis and excessive production of proinflammatory cytokines.[28],[29]
GSK is committed to maximising patient survival through transformational medicines, with a current focus on breakthroughs in immuno-oncology and tumour-cell targeting therapies, and development in haematologic malignancies, gynaecologic cancers, and other solid tumours.
[1] Chifotides, HT, Bose, P, Verstovsek, S. Momelotinib: an emerging treatment for myelofibrosis patients with anemia. J Hematol Oncol. 2022;15(7):1-18.
[2] Shide K et al. Nationwide prospective survey of secondary myelofibrosis in Japan: superiority of DIPSS-plus to MYSEC-PM as a survival risk model. Blood Cancer J. 2023;13(1):110. doi: 10.1038/s41408-023-00869-9
[3] Kirito K et al. Int J Hematol. 2018;107(1):92-97.
[4] Orphanet. Primary Myelofibrosis. 2019. Accessed 01 February 2023. https://www.orpha.net
[5] Takenaka K et al., Clinical features and outcomes of patients with primary myelofibrosis in Japan: report of a 17-year nationwide survey by the Idiopathic Disorders of Hematopoietic Organs Research Committee of Japan. Int J Hematol. 2017 Jan;105(1):59-69. doi: 10.1007/s12185-016-2102-3
[6] Myelofibrosis – Epidemiology Forecast – 2032. DelveInsight. 2022;1-60.
[7] Tefferi A, Lasho TL, Jimma T, et al. One thousand patients with primary myelofibrosis: the mayo clinic experience. Mayo Clin Proc. 2012;87(1):25-33. doi:10.1016/j.mayocp.2011.11.001
[8] Bose P, et al. Curr Hematol Malign Rep. 2018;13:164-172. doi: https://doi.org/10.3109/10428194.2013.813500
[9] Scherber, RM, Mesa, R. Management of challenging myelofibrosis after JAK inhibitor failure and/or progression. Blood Rev. 2020;42:100716. https://doi.org/10.1016/j.blre.2020.100716
[10] Bassiony S, Harrison CN, McLornan DP. Evaluating the Safety, Efficacy, and Therapeutic Potential of Momelotinib in the Treatment of Intermediate/High-Risk Myelofibrosis: Evidence to Date. Ther Clin Risk Manag. 2020;16:889-901. Published 2020 Sep 25. doi:10.2147/TCRM.S258704
[11] Kuykendall AT, Shah S, Talati C, et al. Between a rux and a hard place: evaluating salvage treatment and outcomes in myelofibrosis after ruxolitinib discontinuation. Ann Hematol. 2018;97(3):435-441.
[12] Naymagon, L., Mascarenhas, J. Myelofibrosis-Related Anemia: Current and Emerging Therapeutic Strategies. HemaSphere. 2017;1(1):e1. doi: 10.1097/HS9.0000000000000001
[13] How J, Hobbs GS. A Practical Guide for Using Myelofibrosis Prognostic Models in the Clinic. J Natl Compr Canc Netw. 2020;18(9):1271-1278. https://doi.org/10.6004/jnccn.2020.7557
[14] Nicolosi M, et al. Sex and degree of severity influence the prognostic impact of anemia in primary myelofibrosis: analysis based on 1109 consecutive patients. Leukemia. 2018;32(5):1254-1258. https://doi.org/10.1038/s41375-018-0028-x
[15] Tefferi A, et al. Use of the Functional Assessment of Cancer Therapy–anemia in persons with myeloproliferative neoplasm-associated myelofibrosis and anemia. Clin Ther. 2014;36(4):560-566.
[16] Tefferi A. Primary myelofibrosis: 2021 update on diagnosis, risk-stratification and management. Am J Hematol. 2021;96(1):145-162. https://doi.org/10.1002/ajh.26050
[17] Rumi E, et al. The Genetic Basis of Primary Myelofibrosis and Its Clinical Relevance. Int J Mol Sci. 2020;21(23):8885. https://doi.org/10.3390/ijms21238885
[18] QxMD. DIPSS prognosis in myelofibrosis. Accessed September 12, 2022. https://qxmd.com/calculate/calculator_187/dipss-prognosis-in-myelofibrosis.
[19] QxMD. DIPSS plus score for prognosis of myelofibrosis. Accessed September 12, 2022.
[20] Elena C, et al. Red blood cell transfusion-dependency implies a poor survival in primary myelofibrosis irrespective of IPSS and DIPSS. Haematologica. 2011;96(1):167-170. https://doi.org/10.3324/haematol.2010.031831.
[21] Verstovsek S, et al. MOMENTUM: momelotinib vs danazol in patients with myelofibrosis previously treated with JAKi who are symptomatic and anemic. Future Oncol. 2021;17(12):1449-1458.
[22] Asshoff M, et al. Momelotinib inhibits ACVR1/ALK2, decreases hepcidin production, and ameliorates anemia of chronic disease in rodents. Blood. 2017;129(13):1823-1830.
[23] Oh S, et al. ACVR1/JAK1/JAK2 inhibitor momelotinib reverses transfusion dependency and suppresses hepcidin in myelofibrosis phase 2 trial. Blood Adv. 2020;4(18):4282-4291.
[24] GSK press release issued 15 September 2023: Ojjaara (momelotinib) approved in the US as the first and only treatment indicated for myelofibrosis patients with anaemia. Available at 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/
[25] GSK press release issued 29 January 2024: European Commission authorises GSK’s Omjjara (momelotinib). Available at https://www.gsk.com/en-gb/media/press-releases/european-commission-authorises-gsk-s-omjjara-momelotinib/
[26] MHRA press release issued 31 January 2024: Omjjara licensed for anaemic myelofibrosis patients to treat the symptoms of their disease. Available at https://www.gov.uk/government/news/omjjara-licensed-for-anaemic-myelofibrosis-patients-to-treat-the-symptoms-of-their-disease
[27] Japan Pharmaceuticals and Medical Devices Agency website: https://www.info.pmda.go.jp/psearch/html/menu_tenpu_base.html.
[28] Atallah E, Verstovsek S. Emerging drugs for myelofibrosis. Expert Opin Emerg Drugs. 2012 Dec;17(4):555-70. doi: 10.1517/14728214.2012.748748. PMID: 23186315; PMCID: PMC5009610.
[29] MPN Research Foundation. Primary Myelofibrosis (PMF). 2021. Accessed August 2022. http://www.mpnresearchfoundation.org/primary-myelofibrosis-pmf/
