Valentina Guarneri

Platinum-based chemotherapy and PARP inhibitors for patients with a germline BRCA pathogenic variant and advanced breast cancer (LATER-BC): retrospective multicentric analysis of post-progression treatments

Patients with breast cancer (BC) harbouring a germinal BRCA pathogenic variant (gBRCA-PV) may have an enhanced sensitivity to platinum-based chemotherapy (PBC) and PARP inhibitors (PARPi). As reported in ovarian cancer, however, sensitivity and resistance to these treatments could partially overlap. In patients with a gBRCA-PV and advanced BC (aBC), it remains unclear whether prior exposure to PARPi/PBC affects tumour response to subsequent PBC/PARPi, respectively. We conducted a retrospective, multicentric study to investigate the clinical benefit of post-PBC PARPi and vice versa in patients with a gBRCA-PV and aBC. Patients included had received (neo)adjuvant PBC and then PARPi in advanced setting (group 1), PBC followed by PARPi (group 2) or PARPi followed by PBC (group 3), both in advanced setting. We reported median progression-free survival (mPFS) and disease control rate (DCR) in each group. A total of 67 patients from six centres were included. PARPi-mPFS in advanced setting was 6.1 months in patients in group 1 (N = 12), while PARPi-DCR was 67%. In group 2 (N = 36), PARPi-mPFS was 3.4 months and PARPi-DCR was 64%. Age  6 months were associated with longer PARPi-PFS; previous PBC-PFS > 6 months and PBC in first to second line were associated with longer PARPi-DCR. Patients in group 3 (N = 21) reported a PBC-mPFS of 1.8 months and a PBC-DCR of 14%. PARPi-PFS ≥ 9 months and PARPi-FI ≥ 6 months were associated with better PBC-DCR. Sensitivity and resistance to PARPi and PBC partially overlap in patients with a gBRCA-PV and aBC. Evidence of PARPi activity emerged in patients who progressed on previous PBC.

Pembrolizumab or Placebo Plus Adjuvant Chemotherapy With or Without Radiotherapy for Newly Diagnosed, High-Risk Endometrial Cancer: Results in Mismatch Repair-Deficient Tumors

Mismatch repair-deficient (dMMR) endometrial cancer (EC) is an inflamed phenotype with poor outcomes when meeting high-risk criteria and limited treatment options in the adjuvant setting. We report protocol-prespecified subgroup analysis of patients with dMMR tumors from the phase III ENGOT-en11/GOG-3053/KEYNOTE-B21 study (ClinicalTrials.gov identifier: NCT04634877 ) in newly diagnosed, high-risk EC after surgery with curative intent. Patients were randomly assigned to pembrolizumab 200 mg or placebo (six cycles) plus carboplatin-paclitaxel (four to six cycles) once every 3 weeks, then pembrolizumab 400 mg or placebo once every 6 weeks (six cycles), respectively. MMR status was a stratification factor. Patients received radiotherapy at investigator discretion. Investigator-assessed disease-free survival (DFS) was a primary end point. No formal hypothesis testing was performed for subgroup analysis. In the intention-to-treat population, 141 patients in the pembrolizumab arm and 140 in the placebo arm had dMMR tumors. At this interim analysis, hazard ratio for DFS favored pembrolizumab (0.31 [95% CI, 0.14 to 0.69]); median DFS was not reached in either group. Two-year DFS rates were 92.4% (95% CI, 84.4 to 96.4) and 80.2% (95% CI, 70.8 to 86.9), respectively. No new safety signals occurred. Longer-term follow-up of outcomes will be evaluated at final analysis. Preplanned subgroup analysis on the basis of the study's stratification factors suggests that pembrolizumab plus chemotherapy improves DFS and is clinically relevant for patients with dMMR tumors in the curative-intent setting.