The deal adds to growing global interest in bispecific antibodies that simultaneously inhibit immune checkpoints and tumor angiogenesis. Recently, BioNTech SE announced an $800 million acquisition of Biotheus, a move aimed at bolstering its oncology pipeline. That deal included rights to BNT327/PM8002, a bispecific antibody that, like SSGJ-707, targets PD-L1 and VEGF. At the time, BioNTech stated that clinical trials were expected to initiate by 2025.2
More recently, Akeso's PD-1/VEGF bispecific candidate, ivonescimab, demonstrated superior efficacy compared to tislelizumab plus chemotherapy in first-line treatment of advanced squamous NSCLC. Ivonescimab achieved this in both PD-L1-positive and PD-L1-negative patient populations, highlighting the therapeutic promise of this bispecific class.3
Efficacy Highlights from SSGJ-707 Trials
In January, 3SBio released data from several early- and mid-stage trials of SSGJ-707. In a Phase II trial of PD-L1-positive NSCLC patients without EGFR/ALK mutations, the agent, when combined with chemotherapy, produced a 70.8% overall response rate (ORR) and a disease control rate (DCR) of 100%.
A separate Phase Ia/Ib study in advanced solid tumors showed an ORR of 14% and a DCR of 59.6% with monotherapy. In another Phase II trial in first-line NSCLC, combination therapy with SSGJ-707 and chemotherapy yielded an ORR of 81.3%, with all patients achieving disease control. Additionally, third-line mCRC patients receiving SSGJ-707 monotherapy demonstrated an ORR of 33.3%.4
Manufacturing and Closing Timeline
The transaction is expected to close in the third quarter of 2025, subject to customary regulatory approvals and 3SBio shareholder consent. Upon completion, Pfizer will also make a $100 million equity investment in 3SBio under a previously agreed securities subscription arrangement. Manufacturing plans for SSGJ-707 include producing the drug substance at Pfizer’s site in Sanford, NC, and the drug product in McPherson, Kansas.1
References
1. Pfizer Enters into Exclusive Licensing Agreement with 3SBio. Pfizer. May 19, 2025. Accessed May 20, 2025. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-enters-exclusive-licensing-agreement-3sbio
2. BioNTech SE Strikes Deal to Acquire Biotheus. PharmExec. November 13, 2024. Accessed May 20, 2025. https://www.pharmexec.com/view/biontech-se-strikes-deal-acquire-biotheus
3. Akeso’s PD-1/VEGF Bispecific Antibody Demonstrates Meaningful Progression-Free Survival Benefits in Advanced Squamous NSCLC. PharmExec. April 23, 2025. Accessed May 20, 2025. https://www.pharmexec.com/view/akeso-pd-1-vegf-bispecific-antibody-demonstrates-meaningful-progression-free-survival-benefits-advanced-squamous-nsclc
4. Corporate Presentation. 3SBio. January 16, 2025. Accessed May 20, 2025. https://www.3sbio.com/ImgUpload/files/202501/2025012104422077090.pdf