NEW YORK – Clinical-stage biopharmaceutical company Zentalis Pharmaceuticals said on Monday that it is partnering with Eli Lilly to evaluate Zentalis' ZN-c5, an investigational oral selective estrogen receptor degrader (SERD), in combination with Lilly's CDK4/6 inhibitor abemaciclib (Verzenio), in patients with estrogen receptor-positive, HER2-negative, advanced breast cancer.
Under the terms of the non-exclusive collaboration, Zentalis is responsible for conducting the study involving the combination therapy. Lilly will provide all required doses of abemaciclib, and Zentalis will maintain full ownership of ZN-c5, the companies said. Financial terms of the deal were not disclosed.
ZN-c5 is Zentalis' lead product candidate. In addition to the study exploring ZN-c5 and abemaciclib, Zentalis is conducting a Phase I/II clinical trial of its drug as a monotherapy and in combination with Pfizer's CDK4/6 inhibitor palbociclib (Ibrance) in patients with ER-positive, HER2-negative, advanced or metastatic breast cancer.
The firm is also developing a WEE1 inhibitor, a BCL-2 inhibitor, and an EGFR inhibitor.
Abemaciclib is currently approved by the US Food and Drug Administration for the treatment of hormone receptor-positive, HER2-negative, advanced or metastatic breast cancer in combination with an aromatase inhibitor for postmenopausal women as initial endocrine-based therapy; or in combination with fulvestrant for women with disease progression following endocrine therapy; or as a single agent for adult patients with disease progression following endocrine therapy and prior chemotherapy in the metastatic setting.
"Among its approved indications, abemaciclib is prescribed in combination with hormonal therapy, including fulvestrant, the only FDA-approved SERD, to treat patients with ER-positive, HER2-negative advanced or metastatic breast cancer following endocrine therapy," Zentalis Chairman and CEO Anthony Sun said in a statement. "We have designed ZN-c5 to overcome the limitations of existing hormonal therapies, potentially improving outcomes for breast cancer patients."