Menarini Ricerche Announces Dose Escalation Results of MEN1611 for Breast Cancer

Menarini Ricerche announced the results of the dose escalation part of its B-PRECISE-01 clinical trial (NCT03767335) which is evaluating MEN1611, a potent and selective phosphatidylinositol 3-kinase (PI3K) inhibitor in development for the treatment of breast cancer.

B-PRECISE-01 is an open-label, multicenter, phase Ib, dose escalation and expansion study conducted in patients with HER2-positive, PIK3CA mutated, advanced or metastatic breast cancer, which has progressed after at least two lines of anti-HER2-based therapy. The primary objectives of the study were to determine the safety and the recommended Phase 2 dose (RP2D) of MEN1611 in combination with trastuzumab +/- fulvestrant. Secondary objectives include assessing preliminary clinical activity, pharmacokinetics and pharmacodynamics.

The combination of MEN1611 + trastuzumab +/- fulvestrant has shown an acceptable tolerability profile with no dose-limiting toxicities during the escalation phase, and most treatment emergent adverse events were reversible and manageable with supportive care. The RP2D was established at 48 mg BID. Promising antitumor activity in heavily pretreated patients, together with prolonged disease control, provided the rationale for continuing with the cohort expansion phase of the B-PRECISE-01 study, to test the RP2D in patients with HER2-positive, PIK3CA mutated, advanced or metastatic breast cancer.