# Ivonescimab by Summit Therapeutics

Canonical page: https://technooptimist.io/biotech/ivonescimab
Frontier: [Biotech](https://technooptimist.io/biotech.md) · Field: Antibody drugs · Company: [Summit Therapeutics](https://technooptimist.io/companies/summit-therapeutics.md)
Stage: Pilot (3 of 5: Research → Proto → Pilot → Deploy → Scaling)
Updated: last update 2026-09-15, facts checked 2026-10-11
Goal: Replace PD-1 antibodies like Keytruda as the backbone of cancer immunotherapy by adding blood-vessel blockade in the same molecule, first in lung cancer, where most patients still die within a few years.
Status: Approved in China; FDA decision for EGFR-mutant lung cancer due 14 Nov 2026; Keytruda head-to-head running.
Next milestone: HARMONi-3 squamous cohort: progression-free survival readout, target 2026

## Milestones

| Status | Milestone | Date | Slip |
| --- | --- | --- | --- |
| Done | Summit licenses ivonescimab from Akeso | Dec 2022 |   |
| Done | First approval, by China's NMPA | May 2024 |   |
| Done | HARMONi-2 (China): beats Keytruda on progression-free survival | Sep 2024 |   |
| Done | HARMONi-6 (China): survival gain vs tislelizumab, ASCO plenary | May 2026 |   |
| Done | FDA accepts first US filing (EGFR-mutant lung cancer) | Jan 2026 |   |
| Current | HARMONi-3 squamous cohort: progression-free survival readout | 2026 |   |
| Planned | FDA decision (PDUFA) | 14 Nov 2026 |   |
| Planned | HARMONi-3 non-squamous cohort: progression-free survival readout | 2027 |   |

## Upcoming events

- **2026**: HARMONi-3 squamous cohort: progression-free survival readout
- **14 Nov 2026**: FDA decision (PDUFA)
- **2027**: HARMONi-3 non-squamous cohort: progression-free survival readout

## Most important updates

- **15 Sep 2026**: HARMONi-2 survival data: ivonescimab cuts risk of death by 27% versus Keytruda. At the 2026 World Conference on Lung Cancer, investigators reported that ivonescimab alone extended overall survival compared with Keytruda alone in PD-L1-positive advanced lung cancer in the China HARMONi-2 trial. ([our story](https://technooptimist.io/stories/harmoni-2-survival-data-ivonescimab-cuts-risk-of-death-by-27-versus-936c243d.md) · [original source](https://ascopost.com/news/september-2026/ivonescimab-significantly-improves-overall-survival-vs-pembrolizumab-in-pd-l1-positive-advanced-nsclc/))
- **31 May 2026**: HARMONi-6: ivonescimab plus chemo extends survival over tislelizumab plus chemo in squamous lung cancer. Akeso's China phase 3 HARMONi-6 showed that ivonescimab plus platinum chemotherapy lengthened survival compared with the PD-1 antibody tislelizumab plus chemotherapy as first treatment for squamous lung cancer. ([our story](https://technooptimist.io/stories/harmoni-6-ivonescimab-plus-chemo-extends-survival-over-tislelizumab-55af2e13.md) · [original source](https://www.sec.gov/Archives/edgar/data/0001599298/000159929826000043/ivonescimab-withxchemoth.htm))
- **Jan 2026**: FDA accepts Summit's first ivonescimab filing; decision due 14 Nov 2026, with survival flagged as the key question. The FDA accepted Summit's application for ivonescimab plus chemotherapy in EGFR-mutant non-squamous lung cancer after targeted-pill (TKI) therapy, setting a 14 November 2026 decision date. ([our story](https://technooptimist.io/stories/fda-accepts-summit-s-first-ivonescimab-filing-decision-due-14-nov-2026-66e6270c.md) · [original source](https://www.sec.gov/Archives/edgar/data/0001599298/000159929826000068/smmt-20260630.htm))
- **8 Sep 2024**: Ivonescimab beats Keytruda in HARMONi-2, nearly doubling progression-free survival in lung cancer. Akeso's phase 3 HARMONi-2 trial in China compared ivonescimab head-to-head with Keytruda (pembrolizumab) as first treatment for PD-L1-positive advanced lung cancer. ([our story](https://technooptimist.io/stories/ivonescimab-beats-keytruda-in-harmoni-2-nearly-doubling-progression-7d56fc52.md) · [original source](https://ascopost.com/issues/november-25-2024-supplement-conference-highlights-2024-wclc/harmoni-2-ivonescimab-outperforms-pembrolizumab-as-first-line-treatment-in-nsclc/))

## Current obstacles

- **FDA wants a survival benefit**: HARMONi met progression-free survival but missed significance on survival (HR 0.79); FDA said PFS alone may not suffice.
- **Bleeding and side effects**: VEGF blockade brings bleeding risk; HARMONi-6 saw grade 3+ haemorrhage in 2.6% vs 0.8%, and more serious side effects.
- **Global proof**: The wins over Keytruda come from China-only trials; the multiregional HARMONi-3 must replicate them.

## Physics limits

- **Blood vessels matter outside tumours too**: VEGF keeps normal vessels and wound healing working, so blocking it everywhere brings bleeding, high blood pressure and protein loss in urine that cap how hard it can be pushed.
- **Many tumours don't respond to immunotherapy**: Releasing the PD-1 brake only helps if T cells can recognise the tumour; cancers with few mutations or no T cells inside respond poorly to any PD-1 drug.

## How it works

### PD-1 arm: Releases the immune brake

Tumours switch off T cells through PD-1; blocking it lets T cells attack, the same idea as Keytruda.

### VEGF arm: Cuts the tumour's blood supply

VEGF tells blood vessels to sprout into the tumour and also suppresses immunity; mopping it up does both jobs.

### Cooperation: Stickier where both are present

VEGF raises its PD-1 binding in lab tests, so the drug should concentrate its effect inside tumours.

### Fc-null: Silenced antibody tail

The antibody's tail is disabled so it doesn't recruit immune cells to kill the T cells it is trying to free.

## Spec sheet

| Spec | Ivonescimab | Provenance |
| --- | --- | --- |
| HARMONi-2 PFS hazard ratio vs Keytruda | 0.51 (11.1 vs 5.8 months) | reported |
| HARMONi-2 survival hazard ratio | 0.73 (30.8 vs 22.6 months) | reported |
| HARMONi (global) survival HR | 0.79, p=0.057 (not significant) | reported |
| Half-life | ~10 days | reported |
| Patients treated in trials | 3,000+ | reported |
| HARMONi-3 enrollment | ~1,600 (600 squamous + 1,000 non-squamous) | reported |

Provenance: reported = stated by the company; estimated = our estimate; sample = a sample figure.

## About Summit Therapeutics

Summit develops ivonescimab, a two-in-one antibody licensed from China's Akeso, in its territories (the US, Canada, Europe, Japan, Latin America, the Middle East and Africa). Its first US filing faces an FDA decision in November 2026.

- Licensed ivonescimab from Akeso in Dec 2022: $500M upfront, up to ~$4.56B in milestones, low double-digit royalties.
- FDA decision on the first US filing (EGFR-mutant lung cancer) due 14 Nov 2026; FDA says survival benefit is key.
- Head-to-head lung trial vs Keytruda (HARMONi-3, ~1,600 patients) fully enrolled; first readout expected H2 2026.

- Headquarters: US
- Status: public
- Website: https://www.smmttx.com
- Partners, customers, investors: Akeso (partner)

Company page: https://technooptimist.io/companies/summit-therapeutics.md

## Related programs

Everything in Biotech: https://technooptimist.io/biotech.md

---

The Techno Optimist tracks every frontier of technology, program by program: https://technooptimist.io/ (a Markdown version of any page: add .md to its URL; site map for agents: https://technooptimist.io/llms.txt).
Data API (JSON, realtime stream): https://technooptimist.io/developers. People read 5 pages free, then Reader $10/month; these Markdown pages are open to agents.