Myelofibrosis is a myeloproliferative neoplasm which can exist as a primary disease known as primary myelofibrosis, or can evolve to post-polycythemia vera (PV) or post-essential thrombocythemia (ET) myelofibrosis from PV or ET. It is characterized by the buildup of scar tissue (fibrosis) in bone marrow, which leads to a reduction in blood cell production.

Key Takeaways

• Datamonitor Healthcare estimates that in 2019, there were 49,500 prevalent cases of myelofibrosis in adults aged 50 years and older worldwide, and forecasts that number to increase to 60,700 prevalent cases by 2028.
• The global prevalence of myelofibrosis is estimated to be 0.0027%. Bristol Myers Squibb’s Inrebic and Incyte’s Jakafi are the only marketed drugs for myelofibrosis. These drugs are administered via the oral route.
• The majority of industry-sponsored drugs in active clinical development for myelofibrosis are in Phase II. Therapies in development for myelofibrosis focus on a wide variety of targets. The majority of the pipeline drugs are administered via the oral route.
• High-impact upcoming events for drugs in the myelofibrosis space comprise topline Phase III trial results for pacritinib, Reblozyl, and momelotinib; and an estimated NDA filing for pacritinib.
• The overall likelihood of approval of a Phase I hematologic asset is 10%, and the average probability a drug advances from Phase III is 60.8%. Drugs, on average, take 8.9 years from Phase I to approval, compared to 9.2 years in the overall oncology space.
• There have been only three licensing and asset acquisition deals involving myelofibrosis drugs during 2015–20. The largest deal was the $1,250m agreement in 2015 between Bristol Myers Squibb and Promedior, pursuant to which Bristol Myers Squibb was granted an exclusive right to acquire Promedior along with its lead asset PRM-151, which is in development for idiopathic pulmonary fibrosis and myelofibrosis.
• The distribution of clinical trials across Phase I–IV indicates that the vast majority of trials for myelofibrosis have been in the early and mid-phases of development, with 86% of trials in Phase I–II, and only 14% in Phase III–IV.
• The US has a substantial lead in the number of myelofibrosis clinical trials globally. Germany leads the major European markets, while Israel has the top spot in Asia.
• Novartis has the highest number of completed clinical trials for myelofibrosis, with 15 trials.
• Novartis leads industry sponsors with the highest overall number of clinical trials for myelofibrosis, followed by Incyte.