The anti-TNFR2 antibody BI-1808 is part of BioInvent’s tumor-associated regulatory T cells (Treg)-targeting program. TNFR2 is particularly upregulated on Tregs of the tumor microenvironment and has been shown to be important for tumor expansion and survival, representing a new and promising target for cancer immunotherapy.
BI-1808 and KEYTRUDA® Induce Durable Responses in Heavily Pretreated Platinum-Resistant Ovarian Cancer
STATUS
Updated efficacy data in 34 evaluable patients with a chemotherapy-free regimen; randomized Part C will add BI-1808 to the new standard of care
Data were presented at the ESMO Congress 2026 in Madrid, and update the 25-patient analysis reported at ASCO 2026.
- 24% objective response rate (8 of 34 evaluable patients: 1 complete and 7 partial responses), including patients with high-grade serous and clear cell carcinoma
- 53% disease control rate, with several patients in stable disease beyond 10 months; 6 patients were still on treatment at data cutoff
- Median progression-free survival of 4.1 months per RECIST, compared with 2.1 months reported for pembrolizumab alone1 (indirect comparison); 10.3 months per iRECIST
- Duration of response was not met at cutoff (median follow-up 11.6 months), suggesting that responses are durable
- Well tolerated: fewer than 5% treatment-related discontinuations among 81 solid tumor patients treated with the combination
- Part C will add BI-1808 to pembrolizumab plus weekly paclitaxel ± bevacizumab in a randomized design; first data expected in H2 2027
Patients with recurrent ovarian cancer progressing after platinum therapy (PROC) face a major unmet need, with pembrolizumab monotherapy historically achieving only an 8% response rate. BI-1808, a first-in-class antibody that depletes immunosuppressive Tregs and activates CD8+ T cells by targeting TNFR2, is designed to synergize with PD-1 blockade. In interim Phase 2a results released today, BI-1808 plus pembrolizumab (without chemotherapy) demonstrates a 24% confirmed ORR and 53% disease control rate in this heavily pretreated population, with durable benefit across both high-grade serous and clear cell subtypes, highlighting the potential for a meaningful new option where existing approaches have largely failed.
BioInvent's poster From Modest to Meaningful: Targeting TNFR2 with BI-1808 to Unlock Checkpoint Inhibitor Efficacy in Platinum-Resistant Recurrent Ovarian Cancer (PRROC) received the official Best Poster Award in the Investigational Immunotherapy track at the ESMO Congress 2026.
This award recognizes researchers, clinicians, and scientists who present standout poster abstracts demonstrating high scientific relevance, innovative research design, or impactful clinical data in oncology. Winning the award highlights the quality of both the underlying data and the clear, structured presentation of complex medical research.
STUDY DESIGN
The BI-1808 study (NCT04752826, KEYNOTE-D20) is an ongoing open-label Phase 1/2a study evaluating BI-1808 as a single agent (Part A), in combination with pembrolizumab (Part B) and in combination with pembrolizumab and paclitaxel ± bevacizumab (Part C). Patients were enrolled at 14 study locations in Europe and the United States. The study aims to characterize safety, pharmacokinetics and pharmacodynamics, and assess preliminary antitumor activity by ORR, DoR (duration of response), and progression-free survival (PFS), as measured by RECIST v1.1 and iRECIST.
CLINICAL TRIAL COLLABORATION AND SUPPLY AGREEMENT
KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA. Since August 2021, BioInvent has had a clinical trial collaboration and supply agreement with MSD, a tradename of Merck & Co., Inc., Rahway, NJ., USA, to evaluate the combination of BI-1808 and MSD’s anti-PD-1 therapy, KEYTRUDA (pembrolizumab).
Read more about the ongoing Phase 1/2a study KEYNOTE-D20
Evaluation of BI-1808 for the treatment of solid tumors and T-cell lymphomas.