BioInvent's BI-1808 Plus Pembrolizumab Shows 24% Response Rate in Recurrent Ovarian Cancer
核心洞察
BioInvent's Phase 2a study demonstrates that BI-1808 combined with pembrolizumab achieved a 24% overall response rate in recurrent ovarian cancer (搜索) patients, representing a three-fold improvement over pembrolizumab monotherapy's 8% response rate.
The combination therapy showed a favorable safety profile with manageable adverse events and achieved a 65% disease control rate among 17 evaluable patients.
The company plans to expand the ovarian cancer cohort by enrolling an additional 20 patients focusing on high-grade serous and clear cell subtypes, with data readout expected in the second half of 2026.
BioInvent International AB announced encouraging interim results from its ongoing Phase 2a study evaluating BI-1808, a novel anti-TNFR2 (搜索) antibody, in combination with Merck's pembrolizumab (KEYTRUDA) in patients with recurrent ovarian cancer (搜索) who have progressed following platinum-based therapy. The combination achieved a 24% overall response rate (ORR), representing a meaningful improvement over pembrolizumab monotherapy's 8% ORR demonstrated in the KEYNOTE-100 study.
Clinical Results Demonstrate Promising Efficacy
As of December 18, 2025, 23 patients have been enrolled in the study, with 17 patients evaluated for efficacy. The BI-1808 plus pembrolizumab combination achieved a disease control rate (DCR) of 65%, with 4 partial responses and 7 patients experiencing stable disease. Several patients maintained durable stable disease beyond eight months, with responses ongoing at the time of data cutoff.
"Pembrolizumab has shown meaningful benefit only when combined with chemotherapy, while monotherapy in the KEYNOTE-100 study achieved an ORR of 8%," said Martin Welschof, Chief Executive Officer of BioInvent. "Against this backdrop, observing a 24% response rate and a 65% disease control rate with BI-1808 in combination with pembrolizumab is highly encouraging."
The combination demonstrated a favorable safety and tolerability profile, with all adverse events manageable with standard medical treatments. Some responses were observed after several months of treatment, suggesting that additional responses with potentially important impact on progression-free survival may emerge with longer follow-up.
Targeting High Unmet Need in Recurrent Ovarian Cancer
Treatment of recurrent ovarian cancer (搜索) remains one of the most challenging areas in oncology, with limited treatment options after platinum failure and historically low response rates to immunotherapy. The rationale for combining BI-1808 with pembrolizumab was supported by preclinical studies demonstrating synergistic anti-tumor activity, as well as a complete response observed in a platinum-resistant patient treated with BI-1808 monotherapy.
Exploratory analyses indicate strong activity in both high-grade serous and clear cell ovarian cancer subtypes. Based on these encouraging results, BioInvent plans to expand the ovarian cancer cohort by enrolling an additional 20 patients focusing on these specific subtypes to validate and quantify the signal, with an expected data readout in the second half of 2026.
Novel Mechanism of Action Through TNFR2 Targeting
BI-1808 is a first-in-class anti-TNFR2 (搜索) antibody that targets tumor-associated regulatory T cells (搜索) (Tregs). TNFR2 is particularly upregulated on Tregs within the tumor microenvironment and has been shown to be important for tumor expansion and survival, representing a promising target for cancer immunotherapy.
The drug candidate functions as a ligand-blocking FcγR-engaging antibody that depletes immunosuppressive Treg cells and reprograms myeloid cells. This mechanism of action differentiates BI-1808 from other immunotherapy approaches and provides the rationale for combination with anti-PD-1 (搜索) therapy.
Study Design and Future Development
The Phase 2a trial (NCT04752826) is designed to assess BI-1808 as both a single agent and in combination with pembrolizumab at the recommended Phase 2 dose determined in Phase 1 studies. The study aims to further assess safety and tolerability, characterize pharmacokinetics and pharmacodynamics, and assess preliminary antitumor activity by overall response rate, duration of response, and progression-free survival as measured by RECIST v1.1 and iRECIST criteria.
BioInvent has maintained a clinical trial collaboration and supply agreement with MSD (Merck & Co., Inc.) since August 2021 to evaluate the combination of BI-1808 and pembrolizumab. The partnership reflects the potential of this novel combination approach in addressing the significant unmet medical need in recurrent ovarian cancer (搜索) patients who have limited therapeutic options after platinum-based therapy failure.