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Poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) are metabolized either via carboxylesterase (niraparib) or cytochrome P450 (CYP) enzymes (olaparib and rucaparib). Patients with advanced epithelial ovarian cancer (aOC) who receive concomitant medication metabolized by the CYP system may be at risk of drug-drug interactions impacting PARPi efficacy and tolerability. This study investigated CYP inhibitor/inducer treatment patterns in the first-line maintenance (1Lm) setting for patients with aOC. This retrospective cohort study used de-identified databases of US patients with aOC. Eligible patients were aged ≥18 years, diagnosed with aOC between January 2015-March 2021, and received CYP inhibitors/inducers during 1Lm PARPi initiation or the eligibility window (90 days before to 120 days after first-line platinum-based therapy ended [index]). Patients were either prescribed 1Lm PARPi monotherapy (PARPi cohort) or were not prescribed any 1Lm therapy within 120 days post-index (PARPi-eligible cohort). Strong/moderate CYP inhibitors/inducers were defined as area under the plasma concentration-time curve ratio (AUCR) ≥2 or clearance ratio (CL) ≤0.5 (inhibitors), and AUCR ≤0.5 or CL ratio ≥2 (inducers). Of 1411 patients (median age 63), 158 were prescribed PARPis and 1253 were PARPi-eligible. Among the PARPi cohort, 46.2%, 48.7%, and 5.1% were prescribed niraparib, olaparib, and rucaparib, respectively. For patients prescribed olaparib or rucaparib, 42.4% also received strong and/or moderate CYP inhibitors/inducers. This real-world study indicated a considerable proportion of patients received strong and/or moderate CYP inhibitors/inducers and were prescribed PARPis metabolized by the CYP system. Understanding potential impacts of concomitant CYP inhibitors/inducers on PARPi efficacy and safety is warranted.

Purpose: This paper reports the efficacy of the poly (ADP‐ribose) polymerase inhibitor olaparib alone and in combination with the antiangiogenesis agent cediranib compared with cediranib alone in patients with advanced endometrial cancer. Methods: This was open‐label, randomized, phase 2 trial (NCT03660826). Eligible patients had recurrent endometrial cancer, received at least one (<3) prior lines of chemotherapy, and were Eastern Cooperative Oncology Group performance status 0 to 2. Patients were randomly assigned (1:1:1), stratified by histology (serous vs. other) to receive cediranib alone (reference arm), olaparib, or olaparib and cediranib for 28‐day cycles until progression or unacceptable toxicity. The primary end point was progression‐free survival in the intention‐to‐treat population. Homologous repair deficiency was explored using the BROCA‐GO sequencing panel. Results: A total of 120 patients were enrolled and all were included in the intention‐to‐treat analysis. Median age was 66 (range, 41–86) years and 47 (39.2%) had serous histology. Median progression‐free survival for cediranib was 3.8 months compared with 2.0 months for olaparib (hazard ratio, 1.45 [95% CI, 0.91‐2.3] p =.935) and 5.5 months for olaparib/cediranib (hazard ratio, 0.7 [95% CI, 0.43–1.14] p =.064). Four patients receiving the combination had a durable response lasting more than 20 months. The most common grade 3/4 toxicities were hypertension in the cediranib (36%) and olaparib/cediranib (33%) arms, fatigue (20.5% olaparib/cediranib), and diarrhea (17.9% cediranib). The BROCA‐GO panel results were not associated with response. Conclusion: The combination of cediranib and olaparib demonstrated modest clinical efficacy; however, the primary end point of the study was not met. The combination was safe without unexpected toxicity. Randomized study of cediranib compared with olaparib and the combination for advanced or recurrent endometrial cancer demonstrated progression‐free survival of 3.8, 2.0, and 5.5 months respectively. The treatment toxicities were manageable but the study did not meet its primary end point. [ABSTRACT FROM AUTHOR]