Medicines and Healthcare Products Regulatory Agencyauthorises GSK’s Omjjara (momelotinib) in Great Britainfor treating splenomegaly or symptoms in adultmyelofibrosis patients with moderate to severe anaemia

January 31, 2024 – PharmaceuticalGSK, MHRA, marketing authorisation

First JAK inhibitor treatment in Great Britain specifically indicated for both newly diagnosed and previously treated myelofibrosis patients with moderate to severe anaemia


31 January 2024 — Middlesex, UK — GSK plc today announced that Omjjara (momelotinib) was granted Marketing Authorisation (MA) in Great Britain (GB) by the Medicines and Healthcare products Regulatory Agency (MHRA) for the treatment of 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 thrombocythaemia myelofibrosis and who are Janus kinase (JAK) inhibitor naïve or have been treated with ruxolitinib.

Professor Claire Harrison, deputy chief medical officer of Research, Data and Analytics at Guy’s and St
Thomas’, said: “Myelofibrosis is a rare blood cancer with limited treatment options. The approval of OMJJARA
(Momelotinib) is the culmination of many years of collaboration and participation by hundreds of patients in clinical trials. We are very grateful to those who took part as it has enabled this new option for treating myelofibrosis patients with moderate to severe anaemia.”


Myelofibrosis is a rare type of blood marrow cancer that disrupts the body’s normal production of blood cells. Every year, approximately 380 people are diagnosed with myelofibrosis in the UK. Myelofibrosis can lead to splenomegaly (enlargement of the spleen), constitutional symptoms such as fatigue, night sweats, bone pain, as well as low blood counts, including anaemia (deficiency of red blood cells) and thrombocytopenia (deficiency of platelets). Nearly all people living myelofibrosis are estimated to develop anaemia over the course of the disease and may require additional supportive care, including red blood cell (RBC) transfusions.


Jack Harris, vice-president of UK Oncology at GSK, said: “At GSK, we are committed to driving innovation for those living with unmet needs. We welcome today’s decision. As the first JAK-inhibitor treatment licensed in GB specifically indicated for adult myelofibrosis patients with moderate to severe anaemia, this milestone could have an impact on this patient population living with myelofibrosis across GB. We look forward to working with all stakeholders to help allow eligible myelofibrosis patients to access this treatment on the NHS as soon as possible.”


This MA approval is supported by data from the MOMENTUM phase 3 trial and a subpopulation of adult patients with moderate to severe anaemia (haemoglobin <10 g/dL) from the SIMPLIFY-1 phase 3 trial. The MOMENTUM trial was designed to evaluate the safety profile and efficacy of momelotinib versus danazol for the key manifestations of myelofibrosis (such as splenomegaly, constitutional symptoms and RBC transfusions) in an anaemic, symptomatic, JAK inhibitor-experienced population. The SIMPLIFY-1 trial was designed to evaluate the efficacy and safety profile of momelotinib versus ruxolitinib in myelofibrosis patients who had not received a prior JAK inhibitor therapy.

About GSK
GSK is committed to helping improve 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. GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of
disease together. Find out more at gsk.com.

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