LUND, Sweden, August 7, 2026
BioInvent International AB announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to BI-1808, its first-in-class anti-TNFR2 monoclonal antibody, in combination with pembrolizumab for the treatment of ovarian cancer. The designation recognizes the significant unmet medical need in patients with advanced platinum-resistant ovarian cancer and is intended to facilitate development through more frequent interactions with the FDA, eligibility for rolling review, and the potential for Priority Review. The regulatory milestone follows encouraging Phase 2a clinical data presented at ASCO 2026, where the investigational combination demonstrated promising antitumor activity in heavily pretreated patients. BI-1808 is designed to target TNFR2, a key immune checkpoint highly expressed on regulatory T cells (Tregs) within the tumor microenvironment, helping restore anti-tumor immune responses by reducing immune suppression and enhancing the activity of PD-1 inhibitors
Phase 2a Data Showed Encouraging Clinical Activity
The ongoing Phase 2a study evaluating BI-1808 plus pembrolizumab reported a 24% confirmed overall response rate (ORR) and a 56% disease control rate (DCR) in patients with advanced platinum-resistant ovarian cancer, a population with limited treatment options after platinum-based therapy. Responses were observed across both high-grade serous and clear cell ovarian cancer subtypes, with several patients experiencing durable partial responses and prolonged stable disease, including ongoing responses extending beyond 10 months. Preliminary analyses also showed a median progression-free survival (mPFS) of 10.3 months, substantially exceeding historical outcomes typically seen with pembrolizumab monotherapy, which has demonstrated response rates of approximately 8% in this difficult-to-treat patient population. Based on these findings, BioInvent has initiated cohort expansion to further evaluate BI-1808 in both major ovarian cancer subtypes, with an additional clinical data update expected during the second half of 2026.
Novel TNFR2 Targeting Strategy Strengthens Immunotherapy
BI-1808 represents a first-in-class immunotherapy targeting Tumor Necrosis Factor Receptor 2 (TNFR2), an emerging target involved in maintaining the activity of immunosuppressive regulatory T cells within tumors. By selectively depleting these Tregs while simultaneously activating myeloid cells and CD8+ cytotoxic T cells, BI-1808 aims to enhance the effectiveness of existing immune checkpoint inhibitors such as pembrolizumab without relying on chemotherapy. The investigational therapy has demonstrated a favorable safety profile and encouraging efficacy across multiple solid tumors and T-cell lymphomas in ongoing clinical studies. BioInvent continues its long-standing clinical collaboration with MSD, which provides KEYTRUDA® (pembrolizumab) for combination studies evaluating the potential synergy between TNFR2 inhibition and PD-1 blockade.
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Fast Track Designation Supports Accelerated Development
The FDA Fast Track Designation represents an important regulatory milestone that may accelerate the clinical development and review of BI-1808 as BioInvent advances its ovarian cancer program. The designation provides the company with opportunities for enhanced regulatory engagement, potentially faster submission timelines, and a more efficient path toward registration if future clinical data continue to demonstrate meaningful patient benefit. BioInvent believes TNFR2 inhibition could represent a new class of cancer immunotherapy, particularly for tumors that have shown limited responses to existing checkpoint inhibitors alone. With ongoing Phase 1/2a clinical trials, expanding patient cohorts, and additional efficacy data anticipated later this year, the company is positioning BI-1808 as a promising investigational treatment aimed at improving outcomes for patients with advanced ovarian cancer and other difficult-to-treat malignancies.
Source:BioInvent press release
