Pain medication use in patients with HR+, HER2-neg advanced breast cancer treated with endocrine therapy and a CDK 4/6 inhibitor: A U.S. FDA pooled analysis.

e24145 Background: Pain medications (PMs) are commonly used to treat pain in patients (pts) with advanced/metastatic breast cancer (MBC). We examined PM usage patterns in pts receiving CDK 4/6 inhibitor (CDKI) based treatment. Methods: We pooled data from seven phase 3 randomized, controlled trials of CDKI + endocrine therapy in pts with hormone receptor positive, human epidermal growth factor receptor-2 negative MBC. PM were categorized as opioid (includes codeine-containing), NSAID, or other (i.e. bone-directed, antiepileptic, topical PMs). All analyzed pts received at least 1 dose of CDKI/placebo and had concomitant PM with a documented start date. Medications prescribed during hospitalizations were not included. We evaluated percent PM by demographic factors and pts with bone mets, and liver/lung mets. Results: 2416 pts met the inclusion criteria, of which 928 pts started a PM before the study and 1488 pts did not start PM before the study. Of the 1488 pts not on a PM before the study, 739 started a PM after study started, and 749 did not receive any PM at any time. Of the 739 pts who started a PM only after study start, overall, 59% were prescribed only an NSAID, 10% were prescribed only opioid, 17% were prescribed both an NSAID and opioid, and 14% were prescribed other PMs. The PM use by percent in demographic subgroups in the 1488 pts who took none or more PMs only after study start are presented in the table. Conclusions: To our knowledge, this is the first analysis of PM usage patterns in pts with MBC receiving CDKI or placebo with hormonal therapy on clinical trials. NSAID use was higher than opiates in all prespecified subgroups. Future analyses will examine the benefit of different classes of pain medications in treating symptoms of pain and whether there are differences between study treatment arms Percent PM Use by Class (Patients Who Took None or More PM Only After Study Start). [Table: see text]