Recently, the addition of Pembrolizumab to chemotherapy has showed promising activity in breast cancer patients, improving both pathologic complete response (pCR) and event-free survival (EFS). It has become the standard of care for the treatment of early triple-negative breast cancer (TNBC).
However, continuing pembrolizumab treatment during 6 months after surgery raises concerns about potential overtreatment, specifically in selected good prognosis populations.
We want to investigate whether the discontinuation of pembrolizumab post-surgery is associated with non-inferior survival outcomes compared to the continuation of pembrolizumab treatment for 6 more months (current standard).
OPT-PEMBRO will enrol patients with early-stage, non-metastatic TNBC who experienced pCR after a neoadjuvant chemotherapy plus pembrolizumab regimen. Following surgery, a thorough evaluation of breast cancer status, pathological staging, and assessment of surgical margins will be performed by the local pathologist. Eligible patients will be randomly assigned to one of two arms:
o Control arm: pembrolizumab administered according to one of two possible schedules.
o Experimental arm: observation only. Unlike their counterparts in the control arm, patients in this arm will not receive pembrolizumab after the operation.
| Title | OPTimizing adjuvant prescription of PEMBROlizumab in patients with early-stage triple-negative breast cancer achieving pathologic complete response after standard neoadjuvant chemotherapy and pembrolizumab |
| Participants (P) | OPT-PEMBRO will enrol patients with early-stage, non-metastatic TNBC who experienced pCR after a neoadjuvant chemotherapy plus pembrolizumab regimen |
| Intervention (I) | Observation (suspension of current standard pembrolizumab adjuvant treatment [9 cycles in 6 months]). |
| Control (C) | Pembrolizumab, 200 mg, every 3 weeks for up to 6 months, 9 cycles. Or Pembrolizumab, 400 mg, every 6 weeks for up to 6 months, 4 cycles [standard of care]. |
| Outcome (O) | Determine the non-inferiority of observation compared to 6 months of adjuvant pembrolizumab after surgery in terms of event-free survival (EFS) in patients who experienced pCR after a course of treatment combining neoadjuvant chemotherapy and pembrolizumab |
| Trial Design | The OPT-PEMBRO trial is a pragmatic, international, prospective, randomised (1:1), non-inferiority, multicenter, open-label Phase III clinical trial, mapping onto standard practice in Europe |
| Sample Size | 2454 (200 in Belgium) |
| Trial duration | 174 months (Primary endpoint after 108 months) |
| Budget | 1.48 Mio € |
| Sponsor | Unicancer |
| Chief Investigator | François Duhoux (UCL St Luc – Brussels) |
| External partners | France, Greece, Romania, Bulgaria, Germany, Spain, Switzerland, United Kingdom, Norway, Japan, Italy, Georgia, Argentina, Ireland, Canada |
| Number of participating sites | 10 (+2 optional) in Belgium |
