Bristol Myers' iza-bren held lung cancer back for 11.1 months, almost double chemo's 5.7

Iza-bren kept EGFR mutated lung cancer from growing for a median 11.1 months, against 5.7 months on chemotherapy. Bristol Myers Squibb and its partner SystImmune reported the Phase 3 result on Oct 26. It was a late breaking talk at the ESMO 2026 congress in Madrid. The Lancet published the paper the same day.

Who was in the trial

PANKU-Lung01 enrolled people with non squamous non small cell lung cancer driven by an EGFR mutation. Their cancer had grown despite treatment with an EGFR pill, the tyrosine kinase inhibitors that are the usual first treatment for this cancer.

The trial randomized 216 patients to iza-bren and 206 to platinum based chemotherapy, the standard next step. It ran only in mainland China. Sichuan Biokin, the parent of SystImmune, sponsored it, per the trial record.

The results

An independent panel that did not know each patient’s treatment read the scans. Median follow up was 14.6 months, per the company release.

Median progression free survival was 11.1 months on iza-bren and 5.7 months on chemo. The hazard ratio was 0.40, a 60% lower risk of the cancer growing or death.

Tumors shrank in 60.2% of iza-bren patients and 34.5% of chemo patients. The responses lasted a median 10.4 months on iza-bren and 5.7 months on chemo.

Overall survival data are not mature. The companies reported a favorable trend and gave no number. This analysis was a planned interim look.

Side effects

The most common serious side effects were blood related, such as low blood counts. The companies did not give a rate. 1.9% of iza-bren patients stopped the drug because of side effects.

Two patients, or 0.9%, had confirmed lung inflammation, called interstitial lung disease, per the release. One case was grade 3 and one was grade 1.

What the drug is

Iza-bren, also called BL-B01D1, is an antibody drug conjugate. It is an antibody that carries a chemotherapy payload into cancer cells. It latches on to two proteins, EGFR and HER3, which many cancers make in high amounts.

The FDA gave it Breakthrough Therapy Designation for previously treated, advanced EGFR mutated lung cancer. The designation is meant to speed development and review. The drug is not approved in the US.

The companies say iza-bren has now shown benefit in five Phase 3 trials across five cancers. They are this lung cancer, nasopharyngeal cancer, esophageal cancer, triple negative breast cancer and HR positive, HER2 negative breast cancer.

The US path

Bristol Myers is running its own global trial, IZABRIGHT-Lung01, in the same patients. It plans about 500 patients at 187 sites in 25 countries, including 28 in the US. Its estimated primary completion date is Dec 15, 2028.

Bristol Myers paid $800 million upfront for rights outside China in December 2023. The deal is worth up to $8.4 billion with milestones, per the deal release. The two companies will develop and sell it together in the US.

A US filing date and price: MISSING.

Why it matters: After an EGFR pill stops working, chemo is the usual next step. Iza-bren nearly doubled the time before the cancer grew, and its global trial with 28 US sites is the route to US patients.