June 2, 2026 — A drug developed entirely in China just changed the standard of care for the most aggressive form of lung cancer. On May 31, at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Professor Shun Lu of Shanghai Chest Hospital presented the Phase III HARMONi-6 trial to a standing-room-only Plenary Session — a stage reserved for the most practice-changing studies in oncology. It was the first time in ASCO's 61-year history that a China-originated investigational oncology drug had been selected for that honor.
The drug is ivonescimab (依达方), a bispecific antibody built by Akeso (HKEX: 9926) that simultaneously blocks two pathways cancer exploits to grow: PD-1 (the immune checkpoint) and VEGF (the blood-vessel growth signal). In HARMONi-6, ivonescimab plus chemotherapy reduced the risk of death by 34% compared with tislelizumab (BeiGene's PD-1 inhibitor) plus chemotherapy in 532 patients with previously untreated advanced squamous non-small cell lung cancer (sq-NSCLC). Median overall survival was 27.9 months versus 23.7 months — a 4.2-month absolute gain.
The hazard ratio for death was 0.66 (95% CI 0.50–0.87, P=0.0017), crossing the trial's pre-specified efficacy threshold at a median follow-up of 21.4 months. Median progression-free survival was 11.1 months versus 6.9 months (HR 0.60, P<0.0001). The 12-month overall survival rate was 78.9% with ivonescimab versus 72.2% with the PD-1 comparator; at 24 months it was 64.7% versus 48.6%.
The results were published simultaneously in The Lancet — a rare pairing of a Plenary Session presentation with a top-tier general medical journal, on par with what is normally reserved for large pharma Phase III readouts from the US and Europe. An accompanying editorial by Dr. Tina Cascone of MD Anderson Cancer Center and Dr. Mountzios of Athens asked the title question plainly: "Ivonescimab in advanced squamous non-small-cell lung cancer: can we raise the survival bar?" Their answer, based on the data: yes.
Squamous non-small cell lung cancer accounts for roughly 25–30% of all lung cancer cases. It is closely tied to smoking history, is often centrally located in the chest, and has historically lagged behind other NSCLC subtypes in targeted-therapy options. Until now, the standard first-line treatment for advanced sq-NSCLC without targetable mutations has been a PD-1 inhibitor (tislelizumab, pembrolizumab, nivolumab, atezolizumab) combined with platinum-based chemotherapy. That regimen produces a median overall survival of around 22–24 months in modern trials — a number that has barely budged in five years.
HARMONi-6 is the first large Phase III trial in any lung cancer subtype to show statistically significant improvements in both overall survival and progression-free survival when added head-to-head against a PD-1 plus chemotherapy regimen. The "dual success" is what makes this a Plenary Session-grade result rather than a poster.
Standard PD-1 inhibitors release a single brake on the immune system — they let T cells see and attack cancer. Anti-VEGF drugs cut off the tumor's blood supply but, given as a separate drug alongside a PD-1 inhibitor, they tend to add toxicity (high blood pressure, bleeding, kidney problems, poor wound healing). Ivonescimab combines both functions in a single antibody, designed to deliver the immune-releasing and blood-vessel-starving effects together while avoiding the overlap toxicities of two separate drugs.
The mechanism matters clinically in two ways. First, the HARMONi-6 benefit was seen even in patients whose tumors expressed very low levels of PD-L1 — a biomarker that normally predicts poor response to PD-1 blockade. About 39% of patients in the trial had PD-L1 TPS below 1%, and they still derived benefit. Second, the safety profile was manageable. The investigators reported no new safety signals compared with the known profile of either drug class alone.
HARMONi-6 is the third head-to-head Phase III win for ivonescimab against a PD-1 axis drug, and the second against a PD-1 plus chemotherapy combination:
Akeso says ivonescimab is now being evaluated in more than 30 clinical settings across solid tumors, including 15 Phase III trials — seven of which are head-to-head comparisons against PD-1/PD-L1 therapies. Outside China, the drug is licensed to Summit Therapeutics, which has filed an FDA application for ivonescimab in a different lung cancer indication, with a PDUFA target date of November 14, 2026. No US filing has yet been made for the squamous indication covered by HARMONi-6.
Some context on the patient population is important for international readers thinking about whether these results might apply to them. HARMONi-6 was conducted at 50 sites in China and enrolled only Chinese patients. Baseline characteristics were:
Independent oncologists commenting on the data raised the standard caveat: Chinese patients have historically responded differently to PD-1 and VEGF therapies than Western populations, and the magnitude of the survival benefit may not transfer one-to-one. Suresh Ramalingam of Emory noted that "Chinese patients have historically responded differently to PD-1 and VEGF therapies, which may account for part of the observed benefit." A separate global trial — HARMONi-3 — is enrolling patients in the US, Europe, and elsewhere to test whether the survival gain holds in non-Asian populations.
| Outcome | Tislelizumab + Chemo (control) | Ivonescimab + Chemo (HARMONi-6) |
|---|---|---|
| Patients enrolled | ~266 | ~266 |
| Median overall survival | 23.7 months | 27.9 months |
| Risk of death (hazard ratio) | Reference | 0.66 (34% reduction) |
| Median progression-free survival | 6.9 months | 11.1 months |
| 12-month OS rate | 72.2% | 78.9% |
| 24-month OS rate | 48.6% | 64.7% |
| Patients with PD-L1 <1% | ~39% | ~39% (consistent benefit) |
| Global trial sites | 50 (China only) | 50 (China only) |
| FDA approval status | Available (PD-1 class) | Pending (PDUFA Nov 14, 2026 for different indication) |
| NMPA approval status (China) | Approved (tislelizumab, 2024) | Approved for NSCLC indications; squamous indication filing expected 2026 |
1. Drug access. Ivonescimab is already approved in China for several lung cancer indications, and Akeso has indicated it intends to file for the squamous indication covered by HARMONi-6 with the NMPA in 2026. For an international patient with advanced squamous NSCLC whose home country has not yet approved ivonescimab — including patients in the US, EU, most of the Middle East, and parts of Southeast Asia — China is currently one of the few places where the drug is accessible outside a clinical trial.
2. Cost. PD-1 inhibitors like pembrolizumab (Keytruda) and tislelizumab are expensive. A single dose of pembrolizumab runs $10,000–$12,000 in the US; a full course routinely exceeds $150,000–$250,000 annually. In China, the same drug class costs 50–75% less, and the ivonescimab regimen is priced competitively with domestic PD-1 inhibitors. Even accounting for flights, accommodation, and translation, total treatment cost in China is typically half or less of US pricing.
3. Speed. Chinese Grade 3A hospitals treat large volumes of lung cancer patients — Shanghai Chest Hospital alone runs tens of thousands of thoracic oncology visits per year. International patients can often begin treatment within a week of arrival, with no insurance pre-authorization delay and direct access to the senior oncologist on the trial team. For patients with progressive disease, every month of waiting is meaningful.
These centers have active lung cancer programs with experience on bispecific antibodies and large international patient departments:
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Request a Lung Cancer Assessment →No. As of June 2026, ivonescimab is approved only in China. Summit Therapeutics, which holds the ex-China development and commercialization rights, has filed an FDA application for ivonescimab in a different lung cancer indication (a non-squamous subtype) with a PDUFA target date of November 14, 2026. No US or EU filing has yet been made for the squamous NSCLC indication covered by HARMONi-6. Once Summit's application is reviewed, broader indications may follow, but a US or EU approval specifically for squamous NSCLC is not expected before 2027.
It means the 532 patients were all treated at hospitals in China. This is a common pattern for drugs developed in China before global Phase III trials are launched. The advantage is that the results reflect real-world outcomes in the patient population that today has access to the drug. The disadvantage is that historical differences in PD-1/VEGF response between Asian and non-Asian populations mean the magnitude of benefit may differ when tested in Western patients. HARMONi-3, a separate global Phase III trial run by Summit Therapeutics, is currently enrolling in the US, Europe, and other regions to answer that question.
There is no head-to-head trial yet, and the regimens are not directly comparable across studies. The closest head-to-head data Akeso has produced is HARMONi-2, which tested ivonescimab monotherapy versus pembrolizumab monotherapy in PD-L1-positive NSCLC and showed a 49% reduction in the risk of disease progression. HARMONi-6 tested ivonescimab plus chemotherapy versus tislelizumab plus chemotherapy in squamous disease. Both results favor ivonescimab. A separate global trial of ivonescimab plus chemotherapy versus pembrolizumab plus chemotherapy in squamous NSCLC is ongoing as part of the HARMONi-3 program.
Ivonescimab combines PD-1 and VEGF inhibition in a single molecule, so its side-effect profile overlaps with both drug classes. The most common adverse events are fatigue, hypertension, proteinuria, and immune-related events (thyroid dysfunction, rash, colitis). In HARMONi-6, the rate of grade 3 or higher adverse events was comparable to the tislelizumab plus chemotherapy control arm, and the investigators reported no new safety signals. The drug's dual mechanism did not appear to produce additive toxicity in the way that combining two separate drugs often does.
In most cases, yes — but with an important caveat. The drug is not approved in most countries outside China, so a home-country oncologist would need to apply for named-patient or compassionate-use access, which is not guaranteed. For patients from countries where ivonescimab is unavailable, the practical approach is to complete the induction course (4–6 cycles) in China and then return for maintenance cycles if access can be arranged. Some international patients choose to stay in China for 4–6 months for the full induction and early maintenance period, then transition to local care if a clinical trial or named-patient program becomes available.
Ivonescimab in China runs roughly $4,000–$6,500 per cycle. In the US, pembrolizumab (Keytruda) costs $10,000–$12,000 per dose without insurance, and a full course can exceed $180,000–$250,000. Tislelizumab is cheaper in the US (around $5,000–$8,000 per dose list price) but is not widely available in every market. Adding chemotherapy, hospitalization, and monitoring, total cost in China for a full induction course is typically $35,000–$60,000 all-in, compared with $180,000–$300,000 in the US.
It is the third Phase III trial in which ivonescimab has beaten a PD-1 axis drug head-to-head, and the second to show overall survival benefit. The progression now is from monotherapy comparisons (HARMONi-2) to combination comparisons (HARMONi-6), and from PD-L1-positive populations to all-comers. The next major step is HARMONi-3, a global Phase III trial in squamous and non-squamous NSCLC that will test ivonescimab plus chemotherapy against pembrolizumab plus chemotherapy in a multi-regional population.