Biokin’s Iza-bren hits Phase 3 PFS endpoint in EGFR-Mutant NSCLC, marking 4th positive Phase 3 trial
Sichuan Biokin Pharmaceutical’s izalontamab brengitecan (iza-bren, BL-B01D1) has achieved another major clinical milestone, with the company reporting that its Phase 3 BL-B01D1-301 study in previously treated EGFR-mutant non-small cell lung cancer (NSCLC) met its primary endpoint of progression-free survival (PFS) at a prespecified interim analysis.
According to the latest company disclosure, the independent Data Monitoring Committee (iDMC) determined that the study had met its PFS endpoint, while an overall survival (OS) benefit trend was also observed. The result makes BL-B01D1-301 the fourth Phase 3 study of iza-bren to achieve its primary endpoint. Chinese industry reports described the result as the first positive Phase 3 readout for a bispecific ADC in NSCLC. (ByDrug)
The result adds another layer of validation for iza-bren, an EGFR×HER3 bispecific antibody-drug conjugate (ADC) that Biokin is developing in China and that is being jointly developed by its subsidiary SystImmune and Bristol Myers Squibb (BMS) outside Mainland China.
Phase 3 Success in EGFR-Mutant NSCLC
The BL-B01D1-301 trial, also known as PANKU-Lung01, is a randomized Phase 3 study evaluating iza-bren in patients with locally advanced or metastatic non-squamous NSCLC harboring EGFR-sensitive mutations whose disease progressed following EGFR tyrosine kinase inhibitor (TKI) therapy.
The trial compares iza-bren with platinum-based chemotherapy, including pemetrexed plus cisplatin or carboplatin. The study enrolled approximately 432 patients and is registered as NCT06382116. (ctv.veeva.com)
The latest interim analysis showed that iza-bren achieved the study’s PFS primary endpoint. The company has not yet publicly disclosed the full numerical PFS results, including the median PFS, hazard ratio or p-value, so those data will be important to assess the magnitude of the treatment benefit.
The OS analysis has not yet produced a definitive statistical result, but the reported favorable trend provides an additional signal as the trial continues to mature.
Fourth Phase 3 Win for Iza-bren
The BL-B01D1-301 result is particularly notable because it represents the fourth Phase 3 study in which iza-bren has achieved its primary endpoint.
Earlier in 2026, iza-bren delivered positive results in two additional Phase 3 studies in China.
In BL-B01D1-307 (PANKU-Breast02), iza-bren demonstrated statistically significant and clinically meaningful improvements in both PFS and OS versus physician’s-choice chemotherapy in patients with previously treated triple-negative breast cancer (TNBC). BMS reported a median PFS of 8.5 months versus 3.1 months and median OS of 15.9 months versus 12.5 months, respectively. (Bristol Myers Squibb News)
In BL-B01D1-305 (PANKU-Esophagus01), iza-bren also met both dual primary endpoints of PFS and OS in recurrent or metastatic esophageal squamous cell carcinoma. Median OS was 9.8 months versus 7.2 months, while median PFS was 4.2 months versus 2.0 months compared with chemotherapy. (Bristol Myers Squibb News)
The program’s earlier Phase 3 success came from BL-B01D1-303 in recurrent or metastatic nasopharyngeal carcinoma (NPC). That study demonstrated a statistically significant improvement in objective response rate and PFS versus chemotherapy. (Systimmune)
Taken together, the results increasingly support the potential of iza-bren’s dual-targeting approach across multiple epithelial cancers.
A Potentially First-in-Class EGFR×HER3 Bispecific ADC
Iza-bren is designed to simultaneously target EGFR and HER3, two receptor tyrosine kinases that are frequently expressed in epithelial cancers.
The molecule combines a bispecific antibody with a topoisomerase I inhibitor payload. After binding to tumor cells and undergoing internalization, the ADC releases its payload, generating cytotoxic stress and ultimately inducing tumor-cell death. (Bristol Myers Squibb Investors)
The rationale behind targeting both EGFR and HER3 is to exploit the complementary biology of the two receptors. EGFR signaling is a well-established driver in multiple cancers, while HER3 can participate in compensatory signaling pathways and has been implicated in resistance mechanisms.
This gives iza-bren a potentially differentiated profile compared with conventional ADCs directed against a single target.
Biokin previously described BL-B01D1 as the world’s first clinical-stage EGFR×HER3 bispecific ADC. The program entered human clinical testing in 2021 and has since expanded across multiple tumor types. (HKEX News)
Broad Development Program Across China and the U.S.
The latest NSCLC result comes as Biokin and its partners continue to expand iza-bren’s clinical development program.
As of mid-2026, the program includes more than 40 clinical trials across China and the United States, spanning lung, breast, head and neck, esophageal, ovarian, urothelial and biliary tract cancers.
In China, the company has established a broad group of PANKU registrational studies, including programs in:
- EGFR-mutant and EGFR-wild-type NSCLC
- Small-cell lung cancer
- Esophageal squamous cell carcinoma
- Triple-negative and HR+/HER2-negative breast cancer
- Nasopharyngeal carcinoma
- Ovarian cancer
- Urothelial cancer
- Biliary tract cancer
A number of these studies have received Breakthrough Therapy Designation from China’s Center for Drug Evaluation (CDE). Biokin’s earlier disclosures showed BL-B01D1 already being investigated in multiple Phase 3 settings across lung, breast and other solid tumors. (HKEX News)
Outside China, SystImmune and BMS are advancing iza-bren through a global development program. In August 2025, the U.S. FDA granted Breakthrough Therapy Designation to iza-bren for previously treated advanced EGFR-mutated NSCLC following EGFR TKI and platinum-based chemotherapy. (Bristol Myers Squibb Investors)
BMS Partnership Adds Global Commercial Potential
The program’s global potential is reinforced by its partnership with Bristol Myers Squibb.
Under the collaboration and exclusive license agreement, Biokin’s subsidiary SystImmune and BMS are jointly developing iza-bren outside Mainland China. BMS has highlighted the asset as an important component of its next-generation oncology pipeline, particularly because of its potential across multiple solid tumors. (Bristol Myers Squibb Investors)
The partnership includes development efforts in TNBC, NSCLC and urothelial cancer, among other indications.
The U.S. FDA’s Breakthrough Therapy designation for EGFR-mutated NSCLC further increases the significance of the latest BL-B01D1-301 result. A positive Phase 3 result in the same biomarker-defined population could potentially provide an important clinical and regulatory foundation for future U.S. development.
Iza-bren Is Already Entering the Commercial Stage in China
The latest clinical milestone comes shortly after iza-bren began transitioning from an investigational asset into a commercial product in China.
The drug has received Chinese regulatory approval for recurrent or metastatic nasopharyngeal carcinoma and subsequently for recurrent or metastatic esophageal squamous cell carcinoma, giving Biokin its first commercial footholds for the EGFR×HER3 ADC.
The approvals are particularly significant because they make iza-bren one of the few bispecific ADC programs to move beyond clinical development and into commercial use.
Meanwhile, the company continues to pursue additional indications that could substantially expand the addressable market.
What Comes Next?
The BL-B01D1-301 result strengthens the case for iza-bren as one of the most advanced bispecific ADC programs globally, but the detailed clinical data will now be closely watched.
Key questions will include the magnitude of the PFS improvement, the eventual OS result, safety outcomes and whether the benefit is consistent across clinically relevant EGFR-mutant subgroups.
The study’s OS trend is encouraging but should not be interpreted as a confirmed survival benefit until the OS analysis matures and reaches the appropriate statistical threshold.
Nevertheless, the latest result marks an important milestone for Biokin. With four positive Phase 3 studies, multiple Chinese regulatory approvals, FDA Breakthrough Therapy Designation and a global partnership with BMS, iza-bren has evolved from an experimental bispecific ADC into one of the industry’s most closely watched next-generation oncology programs.
If subsequent readouts continue to demonstrate meaningful survival benefits, iza-bren could potentially become a multi-tumor, multi-line ADC franchise, extending well beyond its initial indications in nasopharyngeal and esophageal cancers.
References
- Biokin / SystImmune — Iza-bren development and partnership information
- Bristol Myers Squibb — Positive Phase III results for iza-bren in TNBC and esophageal cancer
- Bristol Myers Squibb — FDA Breakthrough Therapy Designation for iza-bren in EGFR-mutated NSCLC
- SystImmune — Phase III results for iza-bren in nasopharyngeal carcinoma
- Clinical trial information for BL-B01D1-301 / PANKU-Lung01
- HKEX filing — BL-B01D1 development program and clinical pipeline
- Medical Cube / ByDrug — August 17, 2026 report on BL-B01D1-301 Phase 3 results
Author’s note: The full numerical results from the BL-B01D1-301 interim analysis—including median PFS, hazard ratio, confidence interval and p-value—had not been publicly disclosed in the sources reviewed for this article as of August 18, 2026. The article therefore reports the endpoint result without attributing specific efficacy numbers that have not yet been released.
