Updated FDA pooled analysis of pain medication use in trial participants with HR+, HER2-negative metastatic breast cancer treated with endocrine therapy and a CDK 4/6 inhibitor.

e24101 Background: Pain medications (PMs) are commonly used to treat pain in patients with advanced or metastatic breast cancer (MBC). We previously reported an initial analysis of PM prescribing patterns in clinical trial participants with breast cancer receiving CDK 4/6 inhibitor (CDKI)-based treatment. We present an updated analysis here. Methods: We pooled data from 7 randomized controlled trials of CDKI + endocrine therapy (ET) in patients with HR+, HER2-negative MBC. All analyzed patients received at least 1 dose of CDKI/placebo+ET and a concomitant PM with a documented start date. Medications administered during hospitalizations were not included. We looked at PM use in all patients, patients who took PM only before or after the trial started, and those who took PM both before and during the trial. PMs were categorized as opioid (includes codeine-containing), NSAIDS, or other (i.e. bone-directed, antiepileptic, topical PMs). Results: 4200 patients enrolled across the 7 trials who received at least one dose of CDKI/placebo+ET (n = 2616 CDKI, n = 1548 placebo). Of these, 2881 took a PM at any time (n = 1774 CDKI, n = 1107 placebo). Of the 1774 patients who received CDKI+ET, 487 (27%) took at least one opioid and one NSAID at any time, 782 (44%) took at least one NSAID at any time but no opioids, 244 (14%) took at least one opioid at any time but no NSAIDs, and 261 (15%) took only PM that were not opioids or NSAIDs. Of the 1107 patients who received placebo+ET, 297 (27%) took at least one opioid and one NSAID at any time, 490 (44%) took at least one NSAID at any time but no opioids, 153 (14%) took at least one opioid at any time but no NSAIDS, and 167 (15%) took only PM that were not opioids or NSAIDs. Of the 2881 patients who took a PM at any time, 2038 patients (n = 1222 CDKI, n = 816 placebo) had documented start for their PM. Of these, 544 took PM only before the trial started (n = 334 CDKI, n = 210 placebo), 915 took a PM only during the trial (n = 551 CDKI, n = 364 placebo), and 579 took a PM both before and during the trial (n = 337 CDKI, n = 242 placebo). Overall, more patients took NSAIDs only compared to opioids only. Patient characteristics at baseline were balanced between the two arms. Conclusions: Overall, PM prescribing patterns were similar between the arms. NSAID use was higher than opiates in all groups. These findings are hypothesis generating and additional research is needed to determine the impact of PM on participants’ pain and physical function. Further research should include an understanding of the duration of PM needed in patients with MBC.