Pyrimidine, also known as 1,3-diazobenzene, is a heterocyclic compound with the chemical formula C4H4N2. Pyrimidine is formed by substituting 2 nitrogen atoms for 2 carbons in the meta-position of benzene. It is a diazine and retains its aromaticity. Derivatives of pyrimidine widely exist in organic macromolecular nucleic acids, and many drugs also contain pyrimidine rings. In nucleic acids, three nucleobases are pyrimidine derivatives: cytosine, thymine and uracil. There are a variety of pyrimidine-containing drugs on the market, most of which are kinase inhibitors.
GSK’s novel small molecule drug, Momelotinib (Ojjaara) has been approved by the U.S. FDA on September 15 for the treatment of intermediate or high-risk myelofibrosis, including primary myelofibrosis or secondary myelofibrosis (post-polycythaemia vera and post-essential thrombocythaemia), in adults with anaemia.
Myelofibrosis is a rare and fatal form of bone marrow cancer, often resulting in anemia, constitutional symptoms such as fatigue, night sweats, and bone pain, and splenomegaly. These key manifestations of myelofibrosis, including anaemia, have limited treatment options and causing over 30% patients discontinuing treatment.
Momelotinib fills a significant unmet medical need, and has a potential of being a standard-of-care treatment for newly diagnosed and previously treated patients with anaemia. Under a unique mechanism of action, Momelotinib, inhibits Janus kinase (JAK) 1, JAK2, and activin A receptor, type I (ACVR1) along three key signalling pathways. The phase III study has demonstrated clinical activity against anemia, constitutional symptoms, and splenomegaly.