Blueprint Terminates Clinical-Stage CDK2 Inhibitor Program but Continues Breast Cancer Research

Blueprint Medicines has announced the termination of its clinical-stage CDK2 inhibitor program, including the development of BLU-222, but reaffirmed its commitment to advancing preclinical breast cancer-focused projects. Despite encouraging early data, the company has decided to shift its resources to other promising programs in its pipeline.

The decision affects three CDK2 inhibitors for breast cancer, including BLU-222. In December 2020, Blueprint highlighted “encouraging findings” from a Phase 1 trial of BLU-222 in combination with Novartis’ Kisqali and AstraZeneca’s Faslodex for HR+/HER2- breast cancer. At the time, the company touted the compound’s potency, selectivity, and potential as a first-in-class CDK2 inhibitor. However, these results were insufficient to justify further independent investment in the program.
This week, Blueprint updated shareholders, stating that it will de-fund BLU-222 after completing the Phase 1 dose-escalation study. For much of last year, the company sought a big pharma partner for BLU-222 without success. However, discussions with strategic partners to expand its CDK franchise remain ongoing.
Blueprint’s pipeline still includes two preclinical CDK2 inhibitors, which the company says have progressed more rapidly than expected. These candidates, along with CDK4-targeted programs, could potentially become best-in-class treatments for breast cancer and other solid tumors. As a result, Blueprint plans to increase investments in its CDK franchise.

This strategic shift follows Blueprint’s decision last year to discontinue two NSCLC programs due to unsatisfactory clinical data. The company is redirecting its focus to high-potential assets like Ayvakit, a drug approved for systemic mastocytosis and gastrointestinal stromal tumors, and BLU-808, a KIT inhibitor that has completed Phase 1 trials in healthy volunteers.