Adjuvant Olaparib for Patients with BRCA1- or BRCA2-Mutated Breast Cancer.

BACKGROUND: Poly(adenosine diphosphate-ribose) polymerase inhibitors target cancers with defects in homologous recombination repair by synthetic lethality. New therapies are needed to reduce recurrence in patients with BRCA1 or BRCA2 germline mutation-associated early breast cancer. METHODS: We conducted a phase 3, double-blind, randomized trial involving patients with human epidermal growth factor receptor 2 (HER2)-negative early breast cancer with BRCA1 or BRCA2 germline pathogenic or likely pathogenic variants and high-risk clinicopathological factors who had received local treatment and neoadjuvant or adjuvant chemotherapy. Patients were randomly assigned (in a 1:1 ratio) to 1 year of oral olaparib or placebo. The primary end point was invasive disease-free survival. RESULTS: A total of 1836 patients underwent randomization. At a prespecified event-driven interim analysis with a median follow-up of 2.5 years, the 3-year invasive disease-free survival was 85.9% in the olaparib group and 77.1% in the placebo group (difference, 8.8 percentage points; 95% confidence interval [CI], 4.5 to 13.0; hazard ratio for invasive disease or death, 0.58; 99.5% CI, 0.41 to 0.82; P<0.001). The 3-year distant disease-free survival was 87.5% in the olaparib group and 80.4% in the placebo group (difference, 7.1 percentage points; 95% CI, 3.0 to 11.1; hazard ratio for distant disease or death, 0.57; 99.5% CI, 0.39 to 0.83; P<0.001). Olaparib was associated with fewer deaths than placebo (59 and 86, respectively) (hazard ratio, 0.68; 99% CI, 0.44 to 1.05; P = 0.02); however, the between-group difference was not significant at an interim-analysis boundary of a P value of less than 0.01. Safety data were consistent with known side effects of olaparib, with no excess serious adverse events or adverse events of special interest. CONCLUSIONS: Among patients with high-risk, HER2-negative early breast cancer and germline BRCA1 or BRCA2 pathogenic or likely pathogenic variants, adjuvant olaparib after completion of local treatment and neoadjuvant or adjuvant chemotherapy was associated with significantly longer survival free of invasive or distant disease than was placebo. Olaparib had limited effects on global patient-reported quality of life. (Funded by the National Cancer Institute and AstraZeneca; OlympiA ClinicalTrials.gov number, NCT02032823.).

Pharmacokinetics of pertuzumab administered concurrently with trastuzumab in Chinese patients with HER2-positive early breast cancer.

In the APHINITY study (NCT01358877, BIG 4-11/BO25126/TOC4939G), pertuzumab added to trastuzumab and chemotherapy significantly improved invasive disease-free survival as adjuvant treatment for patients with HER2-positive early breast cancer. The objective of this analysis was to assess the pharmacokinetics of pertuzumab in combination with trastuzumab in Chinese patients with early breast cancer. Samples for pertuzumab and trastuzumab pharmacokinetic analysis were taken from Chinese patients during cycle 1 of treatment and at steady-state in cycle 10. Noncompartmental analysis was used to estimate minimum and maximum serum concentrations (Cmax and Cmin), area under the concentration-time curve, clearance, and other pharmacokinetic parameters. In 15 patients, mean steady-state Cmax and Cmin pertuzumab serum concentrations (368 ± 177 µg/ml, and 122 ± 47 µg/ml, respectively) were numerically higher than observed previously in a pharmacokinetic analysis of the global population in APHINITY and in patients treated in the metastatic setting. The geometric mean ratio and corresponding 90% confidence interval for trastuzumab Cmax and Cmin in the presence (n = 15) or absence (n = 17) of pertuzumab were 104.6 (91.09-120) and 98.23 (84.58-114), respectively, indicating no apparent impact of pertuzumab on the pharmacokinetics of trastuzumab. Increases in pertuzumab Cmax and Cmin were not associated with an increase in adverse events. The APHINITY Chinese pharmacokinetic substudy analysis supports the dosing regimen for pertuzumab (840 mg loading dose followed by 420 mg maintenance doses every 3 weeks administered by intravenous infusion) in a Chinese HER2-positive early breast cancer patient population.

Adjuvant Pertuzumab and Trastuzumab in Early Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer in the APHINITY Trial: Third Interim Overall Survival Analysis With Efficacy Update.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The APHINITY trial (ClinicalTrials.gov identifier: NCT01358877) previously demonstrated that pertuzumab added to adjuvant trastuzumab and chemotherapy improved invasive disease-free survival (iDFS) for patients with early human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC). Here, we report the preplanned third interim analysis of overall survival (OS) and a descriptive updated iDFS analysis with 8.4 years of median follow-up of 4,804 patients in the intent-to-treat population. The 8-year OS was 92.7% in the pertuzumab versus 92.0% in the placebo group (hazard ratio [HR], 0.83 [95% CI, 0.68 to 1.02]; P = .078, above the 0.006 significance threshold). The HR was 0.80 [95% CI 0.63 to 1.00] in the node-positive cohort and 0.99 [95% CI, 0.64 to 1.55] in the node-negative cohort. Updated results of 8-year iDFS in the node-positive cohort showed an absolute improvement of 4.9% favoring pertuzumab (86.1% v 81.2%; HR, 0.72 [95% CI, 0.60 to 0.87]). The node-negative cohort did well without adding pertuzumab (8-year iDFS and OS in the placebo group were 93.3% and 96.4%, respectively). The iDFS benefit was seen in the hormone receptor-negative (HR, 0.82 [95% CI, 0.64 to 1.06]) and HR+ cohorts (HR of 0.75 [95% CI, 0.61 to 0.92]). Despite improvement in overall iDFS, the addition of pertuzumab did not improve OS at this third interim analysis.

Pharmacokinetic and exploratory exposure-response analysis of pertuzumab in patients with operable HER2-positive early breast cancer in the APHINITY study.

PURPOSE: To characterize the pharmacokinetics (PK) of, and perform an exploratory exposure-response (E-R) analysis for, pertuzumab in patients with HER2-positive early breast cancer (EBC) within the APHINITY study (NCT01358877, BIG 4-11/BO25126/TOC4939G). METHODS: A previously developed pertuzumab two-compartment linear population pharmacokinetic (popPK) model was subjected to external validation to examine appropriateness for describing pertuzumab concentrations from the APHINITY study. Pharmacokinetic drug-drug interactions (DDIs) between pertuzumab, trastuzumab, and chemotherapy were assessed by comparing observed serum or plasma Cmax, Cmin, and AUClast geometric mean ratios with 90% CIs. Predictions of pertuzumab Cmax,ss, Cmin,ss, and AUCss were derived from individual parameter estimates and used in an exploratory E-R analysis. RESULTS: Using data from 72 patients, based on goodness-of-fit, the popPK model was deemed appropriate for predictions of individual exposures for subsequent comparisons to historical data, assessment of DDIs, and E-R analyses. No evidence of DDIs for pertuzumab on trastuzumab, trastuzumab on pertuzumab, or pertuzumab on chemotherapy PK was observed. Analyses of differences in exposure between patients with and without invasive disease-free survival events did not indicate improved efficacy with increased exposure. Overall Grade ≥ 3 diarrhea prevalence was higher with pertuzumab versus placebo, but was not greater with increasing pertuzumab exposure. No apparent E-R relationship was suggested with respect to other grade ≥ 3 AEs. CONCLUSION: Overall, the limited available data from this exploratory study suggest that no dose adjustments are needed for pertuzumab when administered in combination with trastuzumab and an EBC chemotherapy regimen.