Transgene and BioInvent to Present Translational Data and Updated Clinical Results on Armed Oncolytic Virus BT-001, at ESMO 2025

- Updated clinical data on BT-001 in combination with pembrolizumab to be presented in a poster

- Tumor shrinkage observed in both injected and non-injected lesions

LUND, SE / ACCESS Newswire / October 13, 2025 / BioInvent International AB ("BioInvent") (Nasdaq Stockholm:BINV)(STO:BINV), a biotech company focused on the discovery and development of novel and first-in-class immune-modulatory antibodies for cancer immunotherapy, Transgene (Euronext Paris: TNG), a biotech company that designs and develops virus-based immunotherapies for the treatment of cancer, will jointly present a poster on translational data and updated clinical results from the Phase 1 study of BT-001 at the European Society for Medical Oncology(ESMO) Annual Meeting. ESMO will take place in Berlin, Germany, from October 17 to 21, 2025.

Key findings of the abstract include:

• Intra-tumoral BT-001 injection in combination with IV pembrolizumab was well tolerated with a manageable safety profile.

• The data showed encouraging and sustained anti-tumor activity in patients with advanced refractory tumors. One patient with PD(L)-1 resistant melanoma and one patient with heavily pretreated but ICI-naive leiomyosarcoma showed partial response (iPR) lasting 6 and 16 months respectively, among the 13 patients who received the combination of intra-tumoral BT-001 (at 10⁷ pfu/mL and 10⁸ pfu/mL) and pembrolizumab.

• Tumor shrinkage was observed in both injected and non-injected lesions.

• BT-001 could be an effective option to improve the response to ICI in refractory patients.

The abstract is available on the ESMO website (here).

BT-001 is an oncolytic virus generated using Transgene's Invir.IO platform and its patented large-capacity VVcopTK-RR- oncolytic virus, which has been engineered to encode both a Treg-depleting recombinant human anti-CTLA-4 antibody generated by BioInvent's proprietary n-CoDeR/F.I.R.S.T platforms, and the human GM-CSF cytokine.

BT-001 is being co-developed as part of a 50/50 collaboration on oncolytic viruses between Transgene and BioInvent. In the Phase 1 part of this study, BT-001 has been shown to be well tolerated as monotherapy and in combination with MSD's (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy KEYTRUDA (pembrolizumab)*.

BT-001 showed first signs of efficacy with clinical response in two out of thirteen patients evaluated, when given in combination with pembrolizumab, with shrinkage of injected and non-injected lesions. Treatment with BT-001 converted "cold" tumors into "hot" ones, and induced T-cell infiltration, as well as PD(L)-1 expression in the tumor microenvironment (ESMO 2024, access press release here).