Neoadjuvant paclitaxel/olaparib in comparison to paclitaxel/carboplatinum in patients with HER2-negative breast cancer and homologous recombination deficiency (GeparOLA study)

Background: The efficacy and toxicity of olaparib as combination therapy in early breast cancer (BC) patients with homologous recombinant deficiency (HRD) [score high and/or germline (g) or tumour (t) BRCA1/2 mutation] is not well described. GeparOLA (ClinicalTriais gov, NCT02789332) investigated olaparib in combination with paclitaxel in HER2-negative early BC with HRD. Patients and methods: Patients with untreated primary HER2-negative cT2-cT4a-d or cT1c with either cN + or pNSIN + or cT1c and triple-negative breast cancer (TNBC) or cT1c and Ki-67>20% BC with HRD were randomised either to paclitaxel (P) 80 mg/m(2) weekly plus olaparib (0) 100 mg twice daily for 12 weeks or P plus carboplatinum (Cb) area under the curve 2 weekly for 12 weeks, both followed by epirubicin/cyclophosphamide (EC). Stratification factors were hormone receptor (HR) status (HR versus HR ) and age (<40 versus >= 40 years). The primary endpoint was pathological complete response (pCR; ypTO/is ypNO). A two-sided one-group chi(2)-test was planned to exclude a pCR rate of <= 55% in the PO-EC arm. Secondary end points were other pCR definitions, breast conservation rate, clinical/ imaging response, tolerability and safety. Results: A total of 107 patients were randomised between September 2016 and July 2018; 106 (PO N = 69; PCb N = 37) started treatment. Median age was 47.0 years (range 25.0-71.0); 36.2% had cT1, 61.0% cT2, 2.9% cT3, and 31.8% cN-positive tumours; grade 3 tumours: 86.8%; Ki-67>20%: 89.6%; TNBC: 72.6%; confirmed gBRCA1/2 mutation: 56.2%. The pCR rate with PO was 55.1% [90% confidence interval (CI) 44.5% to 65.3%] versus PCb 48.6% (90% CI 34.3% to 63.2%). Analysis for the stratified subgroups showed higher pCR rates with PO in the cohorts of patients <40 years and HR patients. Conclusion: GeparOLA could not exclude a pCR rate of <= 55% in the PO arm. PO was significantly better tolerated and the combination merits further evaluation.

Automated summary

The study investigated the efficacy and toxicity of olaparib as combination therapy in early breast cancer patients with homologous recombinant deficiency. The results showed that olaparib had certain efficacy in these patients.