ASCO 2026: Iza New Day For Pretreated Breast Cancer

Research evidence excerpt

ASCO 2026: Iza New Day For Pretreated Breast Cancer

Pharmaceuticals (Major) & Large Cap Biotechnology

Pharmaceuticals - Major - Market Weight

ASCO 2026: Iza New Day For Pretreated Breast Cancer June 2, 2026

Bristol Myers-Squibb (BMY), Pfizer (PFE)

The Wolfe Byte

Iza-bren's (BMY) new MoA (EGFRxHER3) and efficacy in pretreated TNBC were encouraging, though questions were

raised on whether enrolled patients represent the contemporary landscape & will translate to a global population.

Addtl. color on Tukysa's (PFE) HERCLIMB-05 within.

Setting the stage for the late breaking iza-bren presentation, PANKU-Breast02. In our previous conversations

with Bristol (BMY), izalontamab brengitecan (iza-bren), in partnership with SystImmune, was highlighted as one

of the more underappreciated assets within its vast pipeline. Iza-bren represents a first-in-class bispecific ADC

targeting EGFRxHER3 with a topoisomerase I inhibitor payload. The rationale is particularly convincing in TNBC, where

overexpression of both EGFR and HER3 is common. This point was further reiterated by the speaker at ASCO today

who emphasized that the literature points to 70% of breast cancer patients being EGFR+ and almost all expressing

HER3. The PANKU-Breast02 trial investigated iza-bren against physician's choice of chemotherapy in patients with

unresectable locally advanced or metastatic TNBC who progressed on one or two prior lines of therapy.

Iza-bren shows a 71% reduction in time to progression and 40% reduction in risk of mortality. In this randomized

phase 3 study presented at ASCO (LBA1003), iza-bren demonstrated a impressive improvement over chemotherapy.

On PFS, patients on iza-bren had a mPFS of 8.5 months, as compared to 3.1 months for chemotherapy (p<0.0001, HR

0.29).