Cancer Research UK and Sosei Heptares Set for First Human Trial of EP4 Antagonist

Japan-headquartered Sosei Heptares announced it is working with Cancer Research UK to bring its EP4 antagonist treatment candidate, HTL0039732, to its first-ever human trial. The drug is proposed for various oncology targets like microsatellite stable colorectal, head and neck, gastroesophageal, and castrate-resistant prostate cancer, but Sosei did not disclose the clinical trials’ target. 

EP4 Antagonists as a Potentially Valuable Target

Sosei designed HTL0039732 to bind to a type of prostaglandin receptor, a group of lipids that control inflammation, blood flow, and blood clot formation called EP4. Triggering EP4 can potentially encourage cancer cells to evade the immune system and can influence tumor cell growth. 

Dr. Nigel Blackburn, Director of Cancer Research UK’s Centre for Drug Development, said, “People with these cancer types have, to date, largely missed out on some of the remarkable advances in the field of immunotherapy…The hope is that with more trials like this, all cancer patients will eventually be able to benefit from this potentially life-saving form of cancer treatment.”

Sosei said HTL0039732 would be evaluated as a monotherapy and in combination with other immunotherapies. In August, Sosei will present more details about the clinical trial and HTL0039732 at the 2022 Medicinal Chemistry Gordon Research Conference. 

While there are no approved drugs for humans using EP4 antagonists, Galliprant is an EP4 antagonist used to relieve pain in dogs with osteoarthritis. EP4 antagonists entered the immuno-oncology conversation recently, with many new studies boasting its potential. 

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Maintaining Success with its GPCR Development Program

Sosei Heptares is focused on G Protein-Coupled Receptors (GPCRs), a family of cell membrane proteins that act as a signaling pathway for various biological processes. GPCRs have risen in popularity due to their potential across multiple treatment areas. Sosei’s GPCR program has prospered so far, with several large collaborations pushing the company to success.

In November last year, Sosei teamed up with Neurocrine Biosciences to develop schizophrenia and other psychiatric disorder treatment options. The deal consisted of $100 million upfront to Sosei with the potential for a total of $2.6 billion in milestones and royalties.

In another potential nine-figure deal, Sosei partnered with Genentech to develop GPCR targets for undisclosed indications. The deal brought Sosei $26 million upfront with the potential for $1 billion in milestones and royalties. 

The first human trial for HTL0039732 in collaboration with Cancer Research UK is an eventful step for Sosei Heptares and its GPCR platform. EP4 antagonists pose a promising potential, which hopefully, Sosei and Cancer Research UK will be able to harness for underserved cancer indications. 

Author

Reed Slater