BioInvent International has announced promising new data from its ongoing Phase 2a study of BI-1808 monotherapy in patients with cutaneous T-cell lymphoma (CTCL). The results, which will be presented at the European Hematology Association (EHA) 2025 congress in Milan this June, demonstrate significant clinical activity and immune activation in treated patients.
As of the February 20, 2025 data cutoff, eight of ten enrolled CTCL patients were evaluable for response. The treatment showed a 50% objective response rate, with one patient achieving complete response (CR), three patients showing partial response (PR), and four patients maintaining stable disease (SD).
"The emerging clinical responses, along with immune activation reflect the meaningful biological activity of BI-1808 and support further development in hematologic malignancies and solid tumor settings," said Martin Welschof, Chief Executive Officer of BioInvent.
Mechanism of Action and Immune Response
BI-1808 is a first-in-class anti-TNFR2 antibody designed to target tumor-associated regulatory T cells (Tregs). TNFR2 is particularly upregulated on Tregs within the tumor microenvironment and plays a critical role in tumor expansion and survival.
The study revealed important immunological changes in patients receiving treatment. Researchers observed depletion of regulatory T cells and an influx of CD8+ T cells into the skin during the early weeks of treatment, suggesting that BI-1808 effectively stimulates the intended immune response against CTCL.
Safety Profile and Regulatory Status
The treatment demonstrated a favorable safety profile with primarily mild to moderate adverse events. Notably, no grade 3 or higher adverse events were reported in the cohort, indicating good tolerability.
The FDA has recognized the potential of BI-1808 by granting it both Fast Track and Orphan Drug Designations for CTCL, a rare form of non-Hodgkin lymphoma that primarily affects the skin.
Study Design and Future Plans
The current Phase 2a trial (NCT04752826) is evaluating BI-1808 as monotherapy in patients with T-cell lymphomas, including CTCL. The trial is currently in a signal-seeking phase and is expected to enroll a total of 20 patients before moving to a dose optimization phase.
Dr. Stefan K. Barta from the University of Pennsylvania Hospital, the lead author of the upcoming presentation, will present detailed findings in a poster titled "Robust Single Agent Activity of BI-1808, a Tumor Necrosis Factor Receptor 2 (TNFR2) Blocker/Depleter, in Cutaneous T Cell Lymphoma (CTCL) Patients" on June 13, 2025.
Clinical Significance for CTCL Patients
CTCL represents an area of significant unmet medical need, with limited effective treatment options for patients, particularly those with advanced disease.
"We believe that BI-1808 could become a novel treatment option for CTCL patients, where innovative approaches are urgently needed," Welschof added.
The upcoming poster presentation at EHA will include more detailed and recent data, including findings in patients with peripheral T-cell lymphoma (PTCL), further expanding the potential applications of this novel immunotherapy.
Broader Development Program
Beyond the current CTCL study, BI-1808 is being evaluated in other clinical settings. The drug has shown signs of efficacy and a favorable safety profile in combination with pembrolizumab in the ongoing Part B of a Phase 1/2a study, results of which were presented at ASCO 2024.
BioInvent's broader pipeline includes five drug candidates in six ongoing clinical programs in Phase 1/2 trials for the treatment of hematological cancers and solid tumors. The company's proprietary F.I.R.S.T™ technology platform continues to identify both novel targets and the antibodies that bind to them, generating new immune-modulatory candidates for the company's development pipeline.
The full poster presentation from EHA 2025 will be made available on the Scientific Publications section of BioInvent's website following the e-poster disclosure on June 12, 2025.
