ClinicalTrials.gov posted trial results on 31 August 2026 for a pembrolizumab combination study in metastatic or unresectable triple-negative breast cancer. The terminated Phase 1/Phase 2 trial enrolled 5 participants; overall response and disease control rates were reported as 0% in both treatment cohorts.

Background

The study evaluated pembrolizumab with chemokine modulation therapy (CKM), comprising rintatolimod, celecoxib, and interferon alpha 2b. The trial was designed for patients with triple-negative breast cancer that had spread to other parts of the body or could not be removed by surgery. Its stated aims included assessing safety, side effects, and the best dose of the combination.

The conditions listed in the registry were anatomic Stage IV breast cancer, metastatic triple-negative breast carcinoma, and unresectable triple-negative breast carcinoma. The treatment interventions were celecoxib, interferon alpha-2, pembrolizumab, and rintatolimod.

Trial design

This was a Phase 1/Phase 2 study with a total enrollment of 5 participants. The registry listed the overall status as terminated. Results were reported for two cohorts: Cohort I received CKM with pembrolizumab, while Cohort II received CKM with early pembrolizumab.

The registered outcome measures included dose-limiting toxicities, progression-free survival, overall response rate, overall survival, and disease control rate. No primary outcome entries or statistical analyses were supplied in the available data.

Key results

  • Dose-limiting toxicities were reported in 0 participants in Cohort I and 1 participant in Cohort II.
  • Median progression-free survival was 2.3 months in Cohort I and 1.3 months in Cohort II.
  • Overall response rate was 0% in both cohorts.
  • Median overall survival was 10.2 months in Cohort I and 8.7 months in Cohort II.
  • Disease control rate was 0% in both cohorts.

The outcome entries identified a 90% confidence-interval field for several measures, but no confidence-interval values were provided. The record also did not include a separate adverse-event summary.

What this means

In this small, terminated study, the pembrolizumab-containing combination produced no reported responses or disease control in either cohort. The available results also show one dose-limiting toxicity in Cohort II and different median progression-free and overall-survival values between the cohorts.

Because only five participants were enrolled and no statistical analyses or confidence-interval values were supplied, these findings do not establish comparative efficacy or safety. The registry data also do not indicate a new approval, an expanded indication, or a change to pembrolizumab’s clinical use.

Source

Source: ClinicalTrials.gov, trial-results registry record for “Rintatolimod, Celecoxib and Interferon Alpha 2b With Pembrolizumab For the Treatment of Patients With Metastatic or Unresectable Triple Negative Breast Cancer,” dated 31 August 2026. The record is available at clinicaltrials.gov/study/NCT05756166.