For a decade, the way to test a new cancer immunotherapy has been to add it to chemotherapy and compare the result against chemotherapy. Akeso did something rarer. It ran its drug against the class leader, head to head, and won.

On August 12, China’s National Medical Products Administration approved ivonescimab in combination with chemotherapy as a first-line treatment for advanced squamous non-small cell lung cancer. The approval rests on HARMONi-6, a Chinese Phase 3 that pitted ivonescimab plus platinum chemotherapy against tislelizumab, a PD-1 inhibitor, plus the same chemotherapy. Patients on ivonescimab did significantly better on both progression-free and overall survival, with median overall survival of 27.9 months against 23.7 months in the control arm. The data were presented in a plenary session at ASCO earlier this year. It is the third NMPA-approved indication for an ivonescimab regimen since the molecule was first approved in May 2024.

Ivonescimab is a bispecific antibody: one molecule with two different binding arms. One arm blocks PD-1, the brake that tumours press to switch off approaching T cells, the same target hit by pembrolizumab, nivolumab and tislelizumab. The other arm blocks VEGF, the signal tumours send out to grow themselves a blood supply.

Those two make sense together. Blood vessels built under heavy VEGF signalling come out chaotic and leaky, and the environment they create inside a tumour is actively hostile to immune cells trying to get in. Blocking VEGF calms that vasculature down and makes the tumour easier to reach for exactly the T cells that PD-1 blockade has just set free. Doing both jobs with one molecule means both happen in the same place at the same time, which is the entire argument for a bispecific over simply giving two separate antibodies.

Superiority trials against an active comparator are expensive and genuinely risky, because a tie counts as a loss. Most programmes avoid them and design against chemotherapy or placebo instead, where the bar is lower and the answer is more predictable. Akeso has now run two of them: HARMONi-2 against pembrolizumab in PD-L1-high disease, and HARMONi-6 against tislelizumab in squamous disease.

27.9 months against 23.7 is a little over four months of median survival. That is real, and it is also less than the word landmark tends to imply. Both things deserve to be said. The bigger fact is where the evidence came from. A Chinese biotech chose to test its drug against the standard of care rather than around it, won twice, and has collected three approvals in its home market while the molecule works through filings elsewhere. The centre of gravity in oncology development has been shifting for several years. This is what that shift looks like once it reaches a label.

Sources: Akeso / Summit Therapeutics announcement