NEW YORK – Calithera Biosciences on Monday acquired two oncology drugs from Takeda, the TORC 1/2 inhibitor sapanisertib and the SYK inhibitor mivavotinib, in a $45 million deal.
Calithera will pay Takeda $10 million upfront and issue $35 million in Series A preferred stock. Takeda is also eligible to receive high-single digit to low-teens tiered royalties on future sales of the two drugs, along with clinical development, regulatory, and sales milestone payments.
South San Francisco, California-based Calithera will begin a Phase II study of sapanisertib, which targets tumor cells with KEAP1 and NRF2 mutations, in early 2022. That trial will involve patients with relapsed or refractory NRF2-mutated squamous non-small cell lung cancer, an indication in which sapanisertib has previously shown activity.
The acquisition of sapanisertib will complement Calithera's glutaminase inhibitor telaglenastat, which it is also developing for KEAP1- or NRF2-mutated NSCLC patients. Last year, the company began a Phase II randomized study, called KEAPSAKE, of telaglenastat plus pembrolizumab (Merck's Keytruda) and chemotherapy in these patients. The company refocused its development of telaglenastat in 2020 to NSCLC after a study in renal cancer failed to meet its primary endpoint.
Approximately 20 percent of NSCLC patients harbor KEAP1 or NRF2 mutations in their tumors. Calithera CEO Susan Molineaux said in a statement that sapanisertib could be the first targeted treatment for NRF2-mutated squamous NSCLC. "We have learned a great deal about the unmet medical need of patients with KEAP1/NRF2 mutations, as well as how to identify and recruit these patients, during the conduct of our KEAPSAKE trial evaluating telaglenastat," Molineaux said. "This complementary approach in KEAP1/NRF2-mutant squamous NSCLC demonstrates our commitment to these patients and the pathway."
The second drug Calithera acquired from Takeda, mivavotinib, targets the active BCR pathway in non-Hodgkin's lymphoma and the inflammatory signaling pathway in MyD88-mutated non-Hodgkin's lymphoma. Calithera will begin a Phase II study in 2022 of mivavotinib in diffuse large B-cell lymphoma with and without mutations in MyD88 and CD79.