Myelofibrosis: New Drugs to Revolutionize Treatment

The treatment paradigm for myelofibrosis (MF) – a rare type of blood cancer - is expected to experience marked transformation over the next decade in the world’s eight major markets due to numerous late-stage pipeline therapies potentially becoming the new standards of care, according to GlobalData, a leading data and analytics company. The compound annual growth rate (CAGR) is expected to be around 1.9%, driven by the approvals of nine pipeline agents. However, the market growth will be hampered by patent expiries of key marketed MF therapies (1^✔ ✔Trusted Source
Primary myelofibrosis: 2023 update on diagnosis, risk-stratification, and management

Go to source). MF symptoms include anemia and an enlarged spleen (splenomegaly).

Currently marketed therapies for MF are effective for short-term disease control, with almost all patients requiring further treatment, for which there are few treatment options available across the US, France, Germany, Italy, Spain, the UK, Japan, and China.

Unmet Needs and Promising New Therapies in Myelofibrosis

Specifically, Incyte’s Janus Kinase (JAK) inhibitor Jakafi is the undisputed standard of care for MF patients and can rapidly alleviate disease symptoms such as splenomegaly but at the cost of exacerbating anemia.

As the anemia worsens over time, the patients are required to stop taking Jakafi and have few treatment options left. Despite MF being a rare disease, it is a blockbuster market with significant commercial potential.

Jakafi’s landmark approval in 2011 galvanized intensive drug development efforts by providing a strong positive investment signal for this market, as Jakafi is a blockbuster agent. Consequently, a comprehensive late-stage clinical pipeline has set the stage for a revolution in the way MF is treated, resulting in the MF market being of high industry interest over the next decade.

GlobalData estimates that in 2021 Jakafi constituted approximately 65% of global MF market sales and that Jakafi’s patent expiry during the forecast period will significantly negatively impact market growth due to substantial generic/biosimilar erosion.

The range of different therapeutic strategies employed by late-stage pipeline agents is nothing short of impressive, with many of these agents being set to achieve significant financial success and provide new standards of care for currently underserved patient populations.

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Specifically, GSK’s momelotinib is expected to be approved by the FDA later this year and is set to provide a new standard of care for anemic patients with splenomegaly that have progressed on Jakafi.

Constellation Pharmaceuticals’ BET inhibitor pelabresib is also set to gain FDA approval in 2025, straight into the first-line setting in combination with Jakafi with the view to improve clinical responses from day 1 of therapy.

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In February 2022, the FDA granted accelerated approval to CTI BioPharma’s Vonjo, a novel JAK inhibitor uniquely indicated for patients with severely low platelet levels, making it the first agent approved for this very underserved patient population.

Momelotinib is expected to be the most lucrative pipeline agent under its large eligible patient populations and GSK’s global launch capabilities, with peak annual global sales of $575 million.

Researchers believe that among the most important unmet needs are better therapies for anemic patients and more therapy options for patients with severely low platelets, given that none of the current options are effective for improving outcomes for these patient populations (2^✔ ✔Trusted Source
Novel Therapies in Myelofibrosis: Beyond JAK Inhibitors

Go to source).

As such, the focus on key unmet needs will shift to preventing disease progression and improving the durability of therapies, given that current therapies are insufficient to control the disease in the long term.

Pipeline agents such as Geron’s imetelstat and Kartos Therapeutic’s Navtemadlin have shown preliminary efficacy in controlling disease progression, however only time will tell if they can curtail disease progression long-term and how they will be integrated into the treatment paradigm.

References:

1. Primary myelofibrosis: 2023 update on diagnosis, risk-stratification, and management - (https://onlinelibrary.wiley.com/doi/10.1002/ajh.26857)
2. Novel Therapies in Myelofibrosis: Beyond JAK Inhibitors - (https://link.springer.com/article/10.1007/s11899-022-00671-7)

Source-Medindia