Transgene and BioInvent to Present Promising Initial Phase I/IIa Data on Oncolytic Virus, BT-001, at ESMO 2024

Strasbourg, France, and Lund, Sweden, September 9, 2024, 7:00 am CET– Transgene (Euronext Paris: TNG), a biotech company that designs and develops virus-based immunotherapies for the treatment of cancer, and BioInvent International AB (“BioInvent”) (Nasdaq Stockholm: BINV), a biotech company focused on the discovery and development of novel and first-in-class immune-modulatory antibodies for cancer immunotherapy, announce initial promising clinical results from the Phase I part of the ongoing randomized Phase I/IIa trial evaluating BT-001 as a single agent and in combination with MSD’s (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy KEYTRUDA® (pembrolizumab). The Phase I data will be presented at the European Society of Medical Oncology (ESMO) Annual Meeting to be held in Barcelona, Spain, from September 13 to 17, 2024.

Key findings of the abstract include:

• In the monotherapy part, in terms of overall response, stable disease was observed in 4 out of 18 patients with advanced solid tumors receiving BT-001. Additionally, tumor shrinkage was observed in 2 out of 20 injected lesions.
• In the combination part, partial responses were observed in 2 out of 6 heavily pretreated patients with advanced solid tumors receiving BT-001 in combination with pembrolizumab. This includes one patient with a PD(L)-1 resistant melanoma and one patient with a leiomyosarcoma after five lines of therapy. Patient response profiles and updated results will be presented at ESMO.
• BT-001 was well-tolerated with no dose-limiting toxicities (DLTs) observed. Two grade three adverse events related to BT-001 were reported (one skin ulcer and one lymphocyte count decrease). No DLTs were observed with repeated intratumoral injections of BT-001 alone (in 18  patients) or in combination with pembrolizumab (in six patients). 
• BT-001 was shown to replicate and express its anti-CTLA-4 monoclonal antibody (mAb) payload in tumor tissue with rare and sporadic shedding, as shown by preliminary translational data.
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Dr Stéphane Champiat, Medical Oncologist at Gustave Roussy, Head of the Inpatient Unit, Drug Development Department (DITEP) and Clinical Investigator of the study, added: “Many cancer patients fail to respond to existing treatments, emphasizing the significant need for new approaches. BT-001 is a very promising potential new immunotherapy shown to elicit a strong immune response that is further enhanced by the local expression of the anti-immune checkpoint inhibitor CTLA-4 antibody and the cytokine GM-CSF. The initial clinical data from this study provide important proof of principle and demonstrate the relevance of this oncolytic virus. Alone or in combination with pembrolizumab, BT-001 offers the potential to improve therapeutic options with a better safety profile for patients in many types of cancer.”

Dr Alessandro Riva, Chairman and CEO of Transgene, commented: “The promising initial clinical results from the ongoing Phase I/IIa trial of BT-001 demonstrate its potential as a standout asset within Transgene’s oncolytic virus pipeline, highlighting the ability of our invir.IO® platform to generate targeted tumor specific immunotherapies. BT-001 shows preliminary efficacy without dose limiting toxicities, both as monotherapy and in combination with pembrolizumab, with an ability to modulate the tumor microenvironment. We look forward to reporting further results as this study progresses.”

Martin Welschof, CEO of BioInvent, stated: “These are exciting data that further support BioInvent’s belief that BT-001 has the potential to provide an important new treatment option for cancer patients. BT-001 is one of six programs utilizing five BioInvent-generated antibodies, illustrating the depth of our scientific understanding and the power of our approach to improve treatments for patients with unmet needs.”

The abstract #1024P titled “Initial clinical results of BT-001, an oncolytic virus expressing an anti-CTLA4 mAb, administered as single agent and in combination with pembrolizumab in patients with advanced solid tumors” is available on ESMO’s and Transgene’s websites.

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.