Arcus Biosciences and Infinity Pharmaceuticals are teaming up to evaluate their lead oncology programs in triple-combination immunotherapy studies, testing two regimens in both triple-negative breast cancer and ovarian cancer.
The collaboration will examine a combination of Infinity’s IPI-549 in combination with Arcus’ anti-PD-1 antibody AB122 plus AB928, a dual adenosine receptor antagonist. It will also test IPI-549, a PI3K-gamma inhibitor, combined with AB928 and chemotherapy.
The resulting four separate cohorts will be incorporated into Arcus’ recently initiated phase 1/1b trial of AB928 combinations, and are expected to enroll about 15 patients each. Under the agreement, Infinity and Arcus will equally share the expenses of the studies, with initial data expected next year.
“This partnership with Infinity is important as, for the first time, we will be investigating the potential for the triple combination of a selective PI3K-gamma inhibitor, a dual adenosine receptor antagonist, and either a PD-1 inhibitor or chemotherapy to effectively treat patients with triple negative breast cancer or ovarian cancer,” said Arcus CEO Terry Rosen.
The tumor types selected for the project typically show minimal responses to checkpoint inhibitor monotherapy. Macrophages and high adenosine levels are believed to play critical roles in suppressing the immune system in those tumors’ microenvironments, according to the two companies, which hope the triple combinations can provide a promising approach by intervening in multiple mechanisms at once.
“Combining these agents may result in enhanced reduction of pro-tumor immune suppression and increased anti-tumor immune activation,” said Adelene Perkins, CEO and chair of Infinity.
Arcus recently bagged $120 million from an IPO earlier this year—just months after raising $107 million in a November 2017 series C round with backing from Google Ventures, Celgene and Aisling Capital, among others. The Hayward, California-based biotech said it planned to use the money to fund clinical studies of AB928 and AB122 through 2020.
Infinity, however, has seen less luck. In 2016, three years after restructuring following the failure of its lead candidate, the Cambridge, Massachusetts-based company saw its PI3K inhibitor duvelisib achieve its primary endpoint in a phase 2 study in indolent non-Hodgkin lymphoma. But it still fell short of expectations, causing Infinity’s stock price to crumble.
Two weeks later, and after Infinity laid off one-fifth of its staff, AbbVie ended its collaboration with the company and abandoned its rights to the drug, which were established in a 2014 deal worth up to $805 million.