biostudies-literatureNelson BEFoundation for the National Institutes of HealthFoundation for the National Institutes of Health (FNIH)NCI NIH HHS3864-3875https://www.ebi.ac.uk/biostudies/studies/S-EPMC12434394biostudies-literatureUnknown31(18)<h4>Purpose</h4>Intratumoral injection of Clostridium novyi-nontoxic (C. novyi-NT), lacking alpha-toxin, germinates and subsequently replicates in the tumor hypoxic regions, causing cell lysis and inflammation. This phase Ib study investigated the safety and synergistic effects of pembrolizumab and C. novyi-NT in advanced solid tumors.<h4>Patients and methods</h4>Patients with injectable solid tumors received one intratumoral C. novyi-NT injection (day 8) across four dose cohorts (3 × 104 to 100 × 104 spores) with pembrolizumab (200 mg intravenously every 3 weeks, day 0-24 months). Sixteen patients were enrolled with a median age of 62.5 years, and the most common tumor types were breast cancer and melanoma.<h4>Results</h4>The combination therapy demonstrated a manageable safety profile, wClinical cancer research : an official journal of the American Association for Cancer ResearchPhase Ib Study of Pembrolizumab in Combination with Intratumoral Injection of Clostridium novyi-NT in Patients with Advanced Solid Tumors.PMC12434394P30CA016672P30 CA016672Murthy RFu STung DKhazaie KSingh MPKreider BLPiha-Paul SAJanku FDamodaran SPezeshki ACarapanceanu NTsimberidou AMConley APNelson BELeontovich AAAmaria RNCarapanceanu VKarp DDHong DSRodon JVarterasian MNaing ARaghav KPSDumbrava EESheth RAfalsePhase Ib Study of Pembrolizumab in Combination with Intratumoral Injection of Clostridium novyi-NT in Patients with Advanced Solid Tumors.<h4>Purpose</h4>Intratumoral injection of Clostridium novyi-nontoxic (C. novyi-NT), lacking alpha-toxin, germinates and subsequently replicates in the tumor hypoxic regions, causing cell lysis and inflammation. This phase Ib study investigated the safety and synergistic effects of pembrolizumab and C. novyi-NT in advanced solid tumors.<h4>Patients and methods</h4>Patients with injectable solid tumors received one intratumoral C. novyi-NT injection (day 8) across four dose cohorts (3 × 104 to 100 × 104 spores) with pembrolizumab (200 mg intravenously every 3 weeks, day 0-24 months). Sixteen patients were enrolled with a median age of 62.5 years, and the most common tumor types were breast cancer and melanoma.<h4>Results</h4>The combination therapy demonstrated a manageable safety profile, w2025-01-01T00:00:00Z2025 Sep2026-06-03T03:02:16.571Z2026-04-23T03:13:52.854ZS-EPMC124343944064398510.1158/1078-0432.CCR-24-3952