Biomed Valley Discoveries reported a 25% confirmed objective response rate (4 of 16 patients) with a median response duration of 10.93 months in a Phase 1b study combining intratumoral Clostridium novyi-NT with pembrolizumab across advanced solid tumors. Three partial responses and one complete response were observed; stable disease occurred in 69% of patients. Safety was largely manageable, with a single grade 3 dose-limiting abscess and otherwise grade 1–2 events such as injection site reaction, pyrexia, pruritus, leukopenia, and anemia. The maximum tolerated regimen was pembrolizumab 200 mg every three weeks plus a single intratumoral dose of 100 × 10^4 spores.

The results, published in Clinical Cancer Research, extend earlier monotherapy findings and formalize a dosing schema for a live, attenuated bacterial therapy intended to germinate in hypoxic, necrotic tumor regions. The trial, conducted with MD Anderson, used a single intratumoral injection on day 8 across four spore-dose cohorts alongside standard pembrolizumab dosing (day 0 to 24 months). Responses were seen in nasopharyngeal squamous carcinoma, HPV-positive base-of-tongue squamous carcinoma, vulvar melanoma, and chordoma—an uncommon, hard-to-treat sarcoma—suggesting potential cross-histology activity in lesions with accessible necrotic cores.

Strategically, the move signals an escalation from proof-of-biologic activity to combination positioning against PD-1 backbones, aiming to convert localized bacterial tumor lysis into systemic, durable immunity. It differentiates from oncolytic viruses by targeting anaerobic niches that are typically shielded from drugs and immune cells, while accepting operational trade-offs tied to live organisms and procedural delivery. The single-dose paradigm reduces complexity relative to multi-injection intratumoral agents, but raises open questions on optimal scheduling, re-dosing, and patient selection. With small, heterogeneous numbers, the signal is intriguing but not definitive; the company’s stated interest in partnerships indicates recognition that scale-up will hinge on external capabilities in manufacturing, biosafety, and global trial execution.

For sites, this modality imposes distinct requirements: interventional radiology or surgical support for precise intratumoral placement in necrotic zones; infection-control SOPs tailored to anaerobic spore agents; and readiness to manage abscess formation, drainage, and antibiotics. Eligibility will skew toward patients with injection-accessible lesions and radiographically evident necrosis, pushing pre-screen imaging and lesion characterization upstream. CROs should anticipate added logistics—chain-of-custody for a spore product, potential environmental shedding assessments, and containment documentation—alongside rigorous imaging reads and durability assessments. Regulators are likely to scrutinize CMC for spore consistency and sterility, environmental risk and shedding, and the balance of infectious complications versus clinical benefit; alignment on review center and guidance frameworks for live bacterial oncology products will be pivotal. Investigators in head and neck and selected sarcomas may see the fastest path to enrollment given lesion accessibility, while the chordoma responder hints at niche opportunities.

Next, watch for expansion cohorts that test repeat dosing, sequencing relative to PD-1 initiation, and enrichment in PD-1–refractory settings such as HNSCC and melanoma, as well as a chordoma-focused signal-seeking arm. A biomarker plan anchored in hypoxia and necrosis imaging, alongside systemic immune readouts, could sharpen eligibility and de-risk later phases. Any co-development with a PD-1 owner would accelerate global operations. The gating factors are clear: reproducibility in a randomized setting versus PD-1 alone, infection-management predictability at scale, and manufacturing scalability for a live spore product. If those align, this approach could open a procedural, tumor-agnostic niche within the intratumoral immunotherapy landscape.

Source link: https://www.globenewswire.com/news-release/2025/10/07/3162368/0/en/Biomed-Valley-Discoveries-Announces-Publication-of-Results-from-Phase-1b-Study-of-Pembrolizumab-in-Combination-with-Clostridium-novyi-NT-CNV-NT-BVD-550-in-Patients-with-Advanced-So.html

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Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.