Akeso's trispecific antibody AK150, which simultaneously targets the immunosuppressive receptors ILT2, ILT4, and CSF1R, has received Investigational New Drug clearance from China's National Medical Products Administration for clinical trials in patients with advanced solid tumors. The molecule is the first trispecific antibody engaging all three of these myeloid-associated targets to enter clinical development anywhere in the world. Akeso (HKEX: 9926.HK), a Hong Kong-listed biopharmaceutical company with two commercially approved bispecific antibodies already on the market in China, engineered AK150 using its proprietary Tetrabody platform and AI-driven discovery infrastructure. The company's announcement did not disclose trial size, dosing schedule, endpoints, or an estimated completion date, and no clinical trial registry listing has yet been identified.
AK150 works through a three-pronged mechanism: CSF1R blockade depletes M2-like tumor-associated macrophages, while simultaneous ILT2 and ILT4 antagonism disrupts HLA-mediated inhibitory signaling on remaining myeloid cells. ILT2 blockade also has the potential to restore CD8+ T cell and natural killer cell activity. The intended effect is multi-layered relief of immunosuppression in the tumor microenvironment, with particular relevance to tumors resistant to PD-1/PD-L1 checkpoint inhibitors.
Research context
The scientific case for targeting this triad rests on converging preclinical evidence. CSF1/CSF1R blockade has been shown to reprogram tumor-infiltrating macrophages and improve responses to T-cell checkpoint immunotherapy in pancreatic cancer models, as documented in work indexed on AllSci. Separately, ILT4 inhibition has been demonstrated to prevent macrophage-mediated immunosuppression and enhance anti-PD-L1 efficacy in EGFR-activated NSCLC, according to research catalogued on AllSci. Dual antagonism of ILT2 and ILT4 together promotes Th1-polarized immune responses and potentiates anti-cancer immunity, as shown in preclinical characterization of dual LILRB1/LILRB2 antibodies (AllSci). AK150's trispecific format aims to capture these effects simultaneously rather than requiring combination dosing of separate agents.
The trial targets advanced solid tumors broadly, with the company highlighting NSCLC, hepatocellular carcinoma, pancreatic cancer, and refractory breast cancer as indications where all three targets are highly expressed. Current standard of care across these diseases relies heavily on PD-1/PD-L1 checkpoint inhibitors, often combined with chemotherapy or anti-angiogenic agents. Recent approvals have expanded options — nivolumab plus ipilimumab gained approval for first-line HCC in 2025, and NALIRIFOX was approved for first-line metastatic pancreatic adenocarcinoma in 2024 — yet response rates remain limited, particularly in immunologically "cold" tumors. Pancreatic cancer exemplifies the problem: checkpoint inhibitors have shown virtually no efficacy as monotherapy outside the rare microsatellite instability-high subset, and median overall survival remains approximately eleven months even with current regimens.
Several companies are pursuing individual components of AK150's target space, though none with a trispecific approach. NGM Biopharmaceuticals has NGM707, a dual ILT2/ILT4 antagonist, in Phase 1/2 trials for advanced cancers combined with pembrolizumab. Biond Biologics is advancing SAR444881 (BND-22), an ILT2-targeting antibody, in Phase 2 for cholangiocarcinoma and in combination with cetuximab for NSCLC and colorectal cancer. Merck's MK-4830, an anti-ILT4 antibody, is in combination trials for esophageal cancer (AllSci trial listing), while Jounce Therapeutics completed a Phase 1/2 study of JTX-8064 against ILT4 in solid tumors (AllSci). On the CSF1R axis, vimseltinib (Deciphera) remains in Phase 1/2 (AllSci), and pimicotinib (Abbisko/Merck KGaA) has shown activity in tenosynovial giant cell tumor, though CSF1R inhibitors have generally disappointed as monotherapies in solid tumors — cabiralizumab (Five Prime/BMS) failed in pancreatic cancer. The field is thus converging on the view that single-target myeloid modulation is insufficient, and AK150's trispecific design represents one hypothesis for how to move beyond that limitation. Whether simultaneous engagement of three targets on a single molecule confers a pharmacological advantage over combination regimens remains to be tested clinically.
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