Rapt Therapeutics is undergoing a significant transition after the failure of its lead program.
The company is now investing $35 million in a long-acting alternative to Xolair, a drug developed by Novartis and Roche.
Rapt had initially focused on zelnecirnon, a CCR4 agonist being tested for atopic dermatitis and asthma. However, the FDA halted the trials in February due to a case of liver failure, leading Rapt to terminate the program in November.
To address this setback, Rapt has entered into a strategic agreement with Shanghai Jemincare Pharmaceutical to acquire ex-China rights to an anti-immunoglobulin E (IgE) antibody. The antibody, known as RPT904, is currently in phase 2 trials for asthma and chronic spontaneous urticaria, but Rapt plans to prioritize its development for food allergies.
Rapt estimates that peak U.S. sales for food allergy treatments could reach $4.5 billion, and developing RPT904 for chronic spontaneous urticaria could contribute an additional $1 billion in revenue. RPT904 has a longer half-life than Xolair and could potentially serve 16% of moderate-to-severe food allergy patients. Rapt believes that RPT904 could command a premium of at least 30% over biosimilars of Xolair.
The company has received a substantial influx of $150 million in investor funding, which will support the advancement of its clinical programs. Rapt aims to deliver phase 2b food allergy data by the first half of 2027. The successful development of RPT904 could establish Rapt as a leader in the food allergy treatment market.