Olema Oncology Provides Clinical Update Reflecting Strong Progress Across OP-1250 Development Program

Olema Pharmaceuticals, Inc. recently announced clinical development progress for OP-1250, a complete estrogen receptor (ER) antagonist (CERAN) and a selective ER degrader (SERD) in development for the treatment of metastatic breast cancer.

“We are extremely pleased with the emerging clinical profile of OP-1250 and the encouraging progress achieved over the last six months. High investigator enthusiasm has led to rapid enrollment across the development program. In our Phase 1b monotherapy dose expansion, we have seen favorable tolerability and encouraging early anti-tumor activity. In the Phase 1b combination trial with palbociclib, two initial cohorts have completed the dose limiting toxicity evaluation period and we have demonstrated combinability for OP-1250 with no induced metabolism of palbociclib,” said Sean P. Bohen, MD, PhD, President and Chief Executive Officer of Olema Oncology. “We are entering an exciting period with the selection of our Recommended Phase 2 Dose later this month, followed by enrollment in our Phase 2 cohorts and plans to initiate an additional Phase 1b combination trial with each of ribociclib and alpelisib. We expect these datasets will further validate OP-1250’s clinical profile and lay the foundation for our planned pivotal monotherapy study to begin next year.”

Olema continues to be well capitalized with sufficient cash to fund our planned research and development operations into the second half of 2024. As of June 1, 2022, Olema reported the following clinical updates and anticipated milestones for the OP-1250 development program:

Phase 1b Monotherapy Expansion

• Successfully achieved 30 patient targeted enrollment (N=15 each for 60 and 120 mg dose cohorts).
• Favorable tolerability demonstrated, with no grade 3/4 neutropenia and no adverse events that led to discontinuation.
• Encouraging anti-tumor activity observed, including unconfirmed partial responses (uPRs) in the initial group of patients eligible for efficacy evaluation.

Phase 1b Combination with Palbociclib (a CDK4/6 inhibitor)

• Dose escalation progressing as planned. Two initial cohorts have completed the dose limiting toxicity (DLT) evaluation period (30 and 60 mg cohorts), and the 90 mg dose cohort is ongoing.
• Combinability demonstrated in initial cohorts, including no DLTs, tolerability consistent with the expected profile of palbociclib plus endocrine therapy, and no induced metabolism of palbociclib.

Anticipated Milestones

• Select the Recommended Phase 2 Dose (RP2D) for OP-1250 in June 2022, followed by enrollment in the Phase 2 portion of the trial. Phase 2 will include enrollment across three cohorts: patients with measurable disease (N=50), patients with non-measurable disease (N=15) and patients with CNS metastasis (N=15).
• Initiate a Phase 1b combination study with each of ribociclib, a CDK4/6 inhibitor, and alpelisib, a PI3Kα inhibitor, in Q3 2022.
• Present updated monotherapy and initial combination data for OP-1250 in 2H 2022.
• Initiate a pivotal monotherapy study for OP-1250 in 2023.

Olema Oncology is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted therapies for women’s cancers. Olema’s lead product candidate, OP-1250, is an orally-available small molecule with combined activity as both a complete estrogen receptor (ER) antagonist (CERAN) and a selective ER degrader (SERD). It is currently being evaluated as a single agent in an ongoing Phase 1/2 clinical trial, and in Phase 1b combination with palbociclib, in patients with recurrent, locally advanced or metastatic ER-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. Olema is headquartered in San Francisco and has operations in Cambridge, MA.