Single-agent CDK inhibitor therapy

Single-agent abemaciclib was approved by the FDA for use in HER2-negative hormone receptor–positive breast cancer with disease progression on or after endocrine therapy and chemotherapy on the basis of results of the MONARCH 1 trial (NCT02102490).[26] Abemaciclib is the only CDK4/6 inhibitor approved as a single agent. MONARCH 1 was a single-arm phase II study of single-agent abemaciclib in 132 women with HER2-negative hormone receptor–positive, advanced breast cancer that had progressed on at least one line of previous endocrine therapy and at least two lines of previous chemotherapy. The study population was heavily pretreated, and most participants had visceral disease. Patients who had previous CDK inhibitors were excluded. The primary end point was investigator-assessed objective response rate.

Single-agent abemaciclib was approved by the FDA for use in HER2-negative hormone receptor–positive breast cancer with disease progression on or after endocrine therapy and chemotherapy on the basis of results of the MONARCH 1 trial (NCT02102490).[26] Abemaciclib is the only CDK4/6 inhibitor approved as a single agent. MONARCH 1 was a single-arm phase II study of single-agent abemaciclib in 132 women with HER2-negative hormone receptor–positive, advanced breast cancer that had progressed on at least one line of previous endocrine therapy and at least two lines of previous chemotherapy. The study population was heavily pretreated, and most participants had visceral disease. Patients who had previous CDK inhibitors were excluded. The primary end point was investigator-assessed objective response rate.

The objective response rate was 19.7% at 12 months (95% CI, 13.3%–27.5%).

Single-agent abemaciclib was approved by the FDA for use in HER2-negative hormone receptor–positive breast cancer with disease progression on or after endocrine therapy and chemotherapy on the basis of results of the MONARCH 1 trial (NCT02102490).[26] Abemaciclib is the only CDK4/6 inhibitor approved as a single agent. MONARCH 1 was a single-arm phase II study of single-agent abemaciclib in 132 women with HER2-negative hormone receptor–positive, advanced breast cancer that had progressed on at least one line of previous endocrine therapy and at least two lines of previous chemotherapy. The study population was heavily pretreated, and most participants had visceral disease. Patients who had previous CDK inhibitors were excluded. The primary end point was investigator-assessed objective response rate.

The clinical benefit rate was 42.4%.

Single-agent abemaciclib was approved by the FDA for use in HER2-negative hormone receptor–positive breast cancer with disease progression on or after endocrine therapy and chemotherapy on the basis of results of the MONARCH 1 trial (NCT02102490).[26] Abemaciclib is the only CDK4/6 inhibitor approved as a single agent. MONARCH 1 was a single-arm phase II study of single-agent abemaciclib in 132 women with HER2-negative hormone receptor–positive, advanced breast cancer that had progressed on at least one line of previous endocrine therapy and at least two lines of previous chemotherapy. The study population was heavily pretreated, and most participants had visceral disease. Patients who had previous CDK inhibitors were excluded. The primary end point was investigator-assessed objective response rate.

Median PFS was 6.0 months (95% CI, 4.2–7.5).

Single-agent abemaciclib was approved by the FDA for use in HER2-negative hormone receptor–positive breast cancer with disease progression on or after endocrine therapy and chemotherapy on the basis of results of the MONARCH 1 trial (NCT02102490).[26] Abemaciclib is the only CDK4/6 inhibitor approved as a single agent. MONARCH 1 was a single-arm phase II study of single-agent abemaciclib in 132 women with HER2-negative hormone receptor–positive, advanced breast cancer that had progressed on at least one line of previous endocrine therapy and at least two lines of previous chemotherapy. The study population was heavily pretreated, and most participants had visceral disease. Patients who had previous CDK inhibitors were excluded. The primary end point was investigator-assessed objective response rate.

The most common adverse event was diarrhea, which occurred in 90.2% of the participants. However, the majority was grade 1 to 2, and only 19.7% of participants experienced grade 3 diarrhea. There was no grade 4 diarrhea.

Single-agent abemaciclib was approved by the FDA for use in HER2-negative hormone receptor–positive breast cancer with disease progression on or after endocrine therapy and chemotherapy on the basis of results of the MONARCH 1 trial (NCT02102490).[26] Abemaciclib is the only CDK4/6 inhibitor approved as a single agent. MONARCH 1 was a single-arm phase II study of single-agent abemaciclib in 132 women with HER2-negative hormone receptor–positive, advanced breast cancer that had progressed on at least one line of previous endocrine therapy and at least two lines of previous chemotherapy. The study population was heavily pretreated, and most participants had visceral disease. Patients who had previous CDK inhibitors were excluded. The primary end point was investigator-assessed objective response rate.

Neutropenia occurred in 97.7% of participants; however, the majority was grade 1 to 2, and only 26.9% of participants experienced grade 3 to 4 neutropenia.