FDA Grants Fast Track Designation to BioInvent's BI-1808 for Ovarian Cancer

FDA has granted fast track designation to BioInvent International's BI-1808, a first-in-class anti-TNFR2 antibody, for the treatment of ovarian cancer in combination with pembrolizumab, the company announced August 7, 2026.¹ The designation is based on interim phase 2a data presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, in which BI-1808 plus pembrolizumab produced a 24% confirmed objective response rate (ORR) and 56% disease control rate (DCR) in heavily pretreated patients with advanced platinum-resistant ovarian cancer.¹

"Receiving FDA fast track designation for BI-1808 in ovarian cancer is an important milestone that reflects the significant unmet medical need in this difficult-to-treat disease and the strength of the clinical signals we have generated to date," said Martin Welschof, PhD, CEO of BioInvent, in a company press release.¹

What clinical data support the designation?

The phase 2a trial (NCT04752826) evaluates BI-1808 as a single agent, in combination with pembrolizumab, and in triple combination with pembrolizumab and paclitaxel.1The combination cohort presented at ASCO 2026 enrolled 25 heavily pretreated patients with recurrent ovarian cancer who had progressed on platinum-based chemotherapy, including 16 with high-grade serous and 9 with clear cell histology.²

BI-1808 plus pembrolizumab achieved a 24% confirmed ORR and 56% DCR without chemotherapy, with durable responses across both subtypes and a preliminary median progression-free survival of 10.3 months.^1,2 Several responses remained ongoing beyond 10 months, and the combination showed a favorable safety profile with low rates of treatment discontinuation due to adverse events.¹

Why is a new option needed for platinum-resistant ovarian cancer?

Patients with recurrent ovarian cancer who progress after platinum-based therapy face limited options. Pembrolizumab monotherapy has historically achieved only an 8% response rate in this setting.¹ BI-1808 targets TNFR2, depleting immunosuppressive regulatory T cells and activating myeloid cells and CD8-positive T cells in the tumor microenvironment, a mechanism intended to synergize with programmed cell death protein 1 blockade. BioInvent has held a clinical trial collaboration and supply agreement with Merck & Co., known as MSD outside the United States and Canada, since August 2021 to evaluate BI-1808 with Merck's pembrolizumab (Keytruda).¹

What's next for BI-1808?

Cohort expansion is underway, according to the company, focusing on high-grade serous and clear cell ovarian cancer subtypes, with an additional data readout expected in the second half of 2026.¹ BI-1808 is also in clinical development for T-cell lymphoma and other solid tumors, and BioInvent is a clinical-stage biotech advancing multiple immune-modulatory antibody programs through its proprietary F.I.R.S.T. discovery platform.¹

What are the limitations?

Fast track designation facilitates more frequent FDA interactions during development but does not indicate that BI-1808 will ultimately receive accelerated or full approval. The reported efficacy data come from a small, heavily pretreated interim cohort and remain subject to change as the trial's cohort expansion matures.

References

1. BioInvent International. BioInvent receives FDA fast track designation for BI-1808 for the treatment of ovarian cancer. Press release. Published August 7, 2026. Accessed August 7, 2026. https://www.bioinvent.com/en/press/bioinvent-receives-fda-fast-track-designation-bi-1808-treatment-ovarian-cancer-2472829
2. Williams A, Kristeleit R, Lopez JS, et al. BI-1808 + pembrolizumab: responses to a chemotherapy-free regimen in advanced ovarian cancer. J Clin Oncol. 2026;44(16_suppl):2605. doi:10.1200/JCO.2026.44.16_suppl.2605