- High BMI does not adversely affect PFS after treatment with the CDK 4/6 inhibitor abemaciclib plus endocrine therapy (ET) vs placebo plus ET in patients with advanced breast cancer.
Why this matters
- High BMI was predicted to have worse PFS based on findings in early breast cancer.
- Patients with high BMI should be reassured by results.
- Pooled analysis of 1138 patients in the Monarch 2 and 3 randomized controlled trials (RCTs).
- Patients were categorized as underweight (BMI, 2), normal weight (BMI, 18.5-24.9 kg/m2), overweight (BMI, 25-29.9 kg/m2), or obese (BMI, ≥30 kg/m2).
- Funding: None.
- With abemaciclib+ET vs placebo+ET, PFS was prolonged regardless of BMI category.
- Among normal/underweight patients vs those with overweight/obesity, overall response rate was higher in the abemaciclib+ET group:
- 49.4% vs 41.6%.
- OR, 0.73 (95% CI, 0.54-0.99).
- Among normal/underweight patients vs those with overweight/obesity, neutropenia rates were higher in the abemaciclib+ET group:
- 51.0% vs 40.4% (P=.004).
- Weight loss of ≥5% was >3 times more common in the abemaciclib+ET vs placebo+ET group;
- 27.1% vs 10.3%.
- OR, 3.23 (P<.001>
- Results are considered exploratory and warrant further confirmation.