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 could represent a new class of immunomodulatory agent with the potential to improve efficacy of cancer therapy
STATUS
Efficacy in clinical Phase 1/2a study (NCT04752826) in solid tumors
In May 2026, BioInvent announced highly promising early data from its ongoing Phase 2a clinical trial evaluating BI-1808 for the treatment of heavily pretreated patients with advanced ovarian cancer. These data were presented in a poster (#2605) as part of the Developmental Therapeutics - Immunotherapy track at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. Data in summary:
- 24% confirmed ORR (including complete response) in heavily pretreated patients (n=25) with advanced ovarian cancer who received BI-1808 and KEYTRUDA — multiplying by three the historical single agent activity of 8% in KEYNOTE-100 (2019)
- 56% disease control rate (DCR) in the combination arm, including multiple durable responses extending beyond 10 months with patients still on treatment
- The treatment exhibits a very favorable safety profile, and, in contrast to chemotherapy-based regimens, result in very low rates of safety-related treatment discontinuations
- A preliminary median progression-free survival (mPFS) of 10.3 months in the combination arm, based on early PFS analysis
- Activity observed across both high-grade serous and clear cell ovarian cancer subtypes
- Demonstrated robust Treg depletion, reprogramming of myeloid cells, and CD8+ T-cell activation, supporting BI-1808’s differentiated mechanism and combination synergy with pembrolizumab
- Cohort expansion is underway, focusing on high-grade serous and clear cell subtypes, with another data readout expected in H2 2026
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 56% 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. Importantly, prolonged stable disease was observed in multiple patients, with several responses ongoing beyond 10 months, and early analyses indicate a median progression-free survival (mPFS) of 10.3 months.
STUDY DESIGN
This Phase 2a trial (NCT04752826) is designed to assess the safety and tolerability of BI-1808 as a single agent (Part A), in combination with pembrolizumab (Part B) and in a triple combination with pembrolizumab and paclitaxel (Part C). 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.