A phase Ib study of abemaciclib in combination with pembrolizumab for patients with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) locally advanced or metastatic breast cancer (MBC) (NCT02779751): Interim results

Abstract No : 1051

Abstract Type : Poster Discussion Session

Indication : Her2-Negative Breast Cancer

Intervention : abemaciclib + pembrolizumab

Company : Eli Lilly

Technology : CDK4/6 + PD-1


Of 28 pts enrolled, 15 (54%) received 1 line and 10 (36%) 2 lines of prior systemic chemotherapy in the locally advanced/metastatic setting. Safety of the combination was generally consistent with known side effects of abemaciclib and pembrolizumab and was generally manageable. Grade 3/4 adverse events in .2 pts included neutropenia (8 pts/29%), AST increase (5 pts/18%), diarrhea, and ALT increase (3 pts/11% each). Eight pts had confirmed partial response (29% ORR), and disease control rate (complete response [CR]+partial response [PR]+stable disease [SD]) was 82%. Clinical benefit rate (CR+PR+SD persisting for $6 months) was 46%. Median PFS and OS were 8.9 months (95% CI 3.9, 11.1) and 26.3 months (95% CI 20.0, 31.0), respectively.


Combination of abemaciclib plus pembrolizumab demonstrated a generally tolerable safety profile with numerically higher rate of transaminase elevations than reported for the individual treatments. Compared to historical data for abemaciclib monotherapy in a similar pt population, a numerically higher but not obviously different ORR, PFS, and OS was observed.


First combination of a CDK4/6 with a PD-1 inhibitor give hope for entry of PD-1 in the HER2-VE breast cancer setting too.

Refer to Her2-Negative Breast Cancer Market report for detailed Insights.