Rapt Therapeutics is gaining a development partner and a foothold in Asia through a partnership potentially worth $118 million. The biotech is handing Hanmi Pharmaceutical the rights to its lead cancer program in South Korea and greater China in exchange for $10 million upfront and the promise of millions more in milestones.
It’s a win for both companies: Rapt gains entry to markets in the Asia-Pacific region, and Hanmi picks up a program that could become a “keystone” in its immuno-oncology portfolio. In addition to the $10 million upfront fee and a near-term research payment, Rapt stands to net another $48 million in development milestones and $60 million in sales milestones, as well as royalties.
Seoul-based Hanmi picks up the rights to Rapt’s FLX475, a CCR4 antagonist, in South Korea, China, Taiwan and Hong Kong. It will use its clinical trial infrastructure in the region to help Rapt conduct a phase 1/2 study of the drug in what it calls “charged” tumors—that is, tumors with certain characteristics that make them more likely to respond to FLX475. Hanmi will also test the drug in its own phase 2 study in gastric cancer, which is prevalent in Asia.
FLX475 works by blocking the migration of regulatory T cells, or Tregs, into tumors without affecting their movement into healthy tissues. The goal is to stop tumors from co-opting Tregs to tamp down the immune response, a mechanism that is thought to limit the efficacy of cancer drugs such as checkpoint inhibitors. “Charged” tumors have lots of Tregs, CD8+ effector T cells and CCR4 ligands—the target of FLX475.
"Within this charged group, there are tumor types that are highly prevalent globally, such as lung cancer, head and neck cancer and triple-negative breast cancer,” Rapt CEO Brian Wong, M.D., Ph.D., told FierceBiotech. “But some tumor types are more endemic to Asia, including gastric cancer and nasopharyngeal cancer, for example.”
Rapt sought a partner to connect with patients in Asia and complement the development work it’s been doing for FLX475. Hanmi emerged the winner.
As they advance FLX475, the companies will share their data. “Data from the Hanmi trial will enable our global development and vice versa, the data we are generating in our trial will enable their development in Korea and China,” Wong said.
The phase 1/2 study is testing FLX475 on its own and in combination with Merck’s Keytruda in a range of “charged” tumors, including Hodgkin and non-Hodgkin lymphomas and virally-associated cancers such as head and neck cancers caused by the human papillomavirus. The trial is slated to read out in the first half of 2020.
The Hanmi deal may be Rapt’s first step into Asia, but it won’t be the last.
“This collaboration is narrowly focused on South Korea and China—it does not include other territories within Asia and it doesn’t include other territories throughout the world,” Wong said. “It’s a nice start and provides us with an entry point into the Asian market, but there are certainly other parts of Asia and the rest of the world where we could partner ‘475.”