BMS Just Showed Up to the ADC Party With a Weapon Nobody Expected

BMS also showed Phase 3 results in esophageal squamous cell carcinoma, where iza-bren cut the risk of death by 36%, extending median survival from 7.2 to 9.8 months.

Why TROP2 Players Should Be Nervous

Here's what makes this uncomfortable for Gilead, AstraZeneca, and Daiichi Sankyo. Iza-bren just posted competitive survival numbers in TNBC, a tumor type where TROP2 drugs have been the go-to option for later-line treatment. And it did so by targeting completely different biology.

That creates a strategic problem. If a non-TROP2 drug can match or rival TROP2 ADC outcomes, then the entire value proposition of the TROP2 class gets questioned. Doctors and payers will inevitably ask: why commit to TROP2 targeting when a bispecific ADC hitting EGFR and HER3 delivers similar (or better) results?

The safety profile adds another layer. Interstitial lung disease (ILD), a serious inflammatory lung condition, is the boogeyman of ADC therapy. Iza-bren showed an all-grade ILD rate of just 1.4% in the TNBC trial. That's notably low for the ADC class and could be a major selling point, especially if BMS pushes into lung cancer, where ILD risk makes oncologists particularly cautious.

The drug isn't without downsides. Grade 3 or higher blood count drops were common: low platelets hit 52.7% of patients, and anemia affected 46.9%. Those are meaningful toxicities. But they're manageable ones, the kind oncologists are used to handling with dose adjustments and supportive care.

The Bigger Picture: BMS's ADC Chess Move

Iza-bren isn't a one-tumor wonder in BMS's playbook. The company already has FDA Breakthrough Therapy Designation for the drug in previously treated EGFR-mutant non-small cell lung cancer. Global Phase 2/3 trials are running in bladder cancer and first-line TNBC. BMS is clearly building a multi-tumor franchise around this single asset.

And they're not stopping at monotherapy. BMS leadership has signaled interest in novel-novel combination strategies, pairing precision-targeted ADCs with immune-boosting bispecifics. That approach could be potent. It's the oncology equivalent of a one-two punch: the ADC poisons the tumor while the bispecific rallies the immune system.

The Competitive Landscape Just Got Messier

The ADC market is projected to balloon from roughly $15.6 billion in 2025 to over $70 billion by 2031. TROP2 drugs were supposed to be a cornerstone of that growth. Trodelvy and Dato-DXd have been positioning themselves across breast, lung, and other solid tumors, with topoisomerase-1 ADCs already accounting for more than half of all ADC revenue.

But iza-bren's data introduce a genuinely different competitive dynamic. This isn't another TROP2 "me too" drug fighting for share within the same target class. It's an entirely different approach that could siphon patients away from TROP2 drugs if the data hold up in global populations.

Wall Street's reaction has been measured but interested. Analysts describe BMS as "quietly building its next growth cycle," with iza-bren as a central pillar. The consensus: the data are strong, but investors want to see mature global results before fully pricing in a franchise-level opportunity. BMS still faces massive patent cliffs on Eliquis and legacy assets, so the pressure to turn pipeline into revenue is real.

What Happens Next

The China data are compelling, but they're China data. The real test comes when BMS's global trials read out. Can iza-bren replicate these results in broader, more diverse patient populations? Can it eventually go head-to-head with TROP2 ADCs in randomized trials?

For now, the message from ASCO 2026 is clear: the assumption that TROP2 would dominate the ADC landscape is no longer safe. BMS just proved that you can hit different targets, deliver the same class of payload, and get results that make the entire field rethink its assumptions. The TROP2 incumbents aren't dethroned yet, but they're officially on notice.

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