Trial results for the Phase 2 study NCT03095352, investigating pembrolizumab with carboplatin in breast cancer patients with chest wall disease, were posted on ClinicalTrials.gov on 2025-12-22. The combination arm showed a Disease Control Rate (DCR) of 20 percentage of participants at 18 weeks, compared to 17 percentage of participants for carboplatin monotherapy.
Background
Pembrolizumab (Keytruda) is an immunotherapy drug. The trial focused on breast cancer patients with chest wall disease who had either hormone-resistant (estrogen receptor positive/progesterone receptor positive/human epidermal growth factor receptor 2 negative breast cancer with progressive disease on 2 prior lines of hormonal therapy) or triple-negative (estrogen receptor negative/progesterone receptor negative/human epidermal growth factor receptor 2 negative) breast cancer.
Trial design
The study, NCT03095352, was a Phase 2 multicenter trial that enrolled 76 participants with breast cancer and chest wall disease. The trial compared two treatment arms: Arm A received pembrolizumab plus carboplatin, while Arm B received carboplatin monotherapy, with pembrolizumab administered only to participants in this arm who experienced progression.
Key results
The trial reported several key outcomes at 18 weeks:
- For Disease Control Rate (DCR):
- Arm A (Pembrolizumab + Carboplatin) achieved a DCR of 20 percentage of participants.
- Arm B (Carboplatin Monotherapy) achieved a DCR of 17 percentage of participants.
- For Median Progression Free Survival (PFS):
- Arm A (Pembrolizumab + Carboplatin) had a median PFS of 2.06 months.
- Arm B (Carboplatin Monotherapy) had a median PFS of 2.63 months.
- For Disease Control Rate by Immune-related (ir) RECIST:
- Arm A (Pembrolizumab + Carboplatin) showed a DCR of 18 percentage of participants.
- Arm B (Carboplatin Monotherapy) showed a DCR of 17 percentage of participants.
- For Objective Response Rate (ORR):
- Arm A (Pembrolizumab + Carboplatin) had an ORR of 8 percentage of participants.
- Arm B (Carboplatin Monotherapy) had an ORR of 12.5 percentage of participants.
- Regarding Treatment-related Adverse Events (AEs):
- 33 Participants in Arm A (Pembrolizumab + Carboplatin) experienced AEs.
- 12 Participants in Arm B (Carboplatin Monotherapy) experienced AEs.
- 6 Participants in Arm BX (Arm B Participants Who Progressed) experienced AEs.
What this means
The results of this Phase 2 trial present a mixed efficacy profile for pembrolizumab combined with carboplatin compared to carboplatin monotherapy in breast cancer patients with chest wall disease. While the combination arm showed a slightly higher Disease Control Rate, the median Progression Free Survival and Objective Response Rate were lower than with carboplatin alone. Additionally, the combination arm was associated with a higher number of treatment-related adverse events. These findings suggest that the addition of pembrolizumab to carboplatin in this specific patient population did not demonstrate a clear benefit across all measured efficacy endpoints and was associated with increased adverse events.
Source
The information for these trial results was sourced from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03095352, titled "Pembrolizumab With Carboplatin Compared to Carboplatin Alone in Breast Cancer Patients With Chest Wall Disease," were posted on 2025-12-22 on clinicaltrials.gov.