trastuzumab pamirtecan (BNT323) / DualityBio, BioNTech, 3SBio - LARVOL DELTA

Pumitamig + trastuzumab pamirtecan (T-Pam) in patients (pts) with HR+, HER2-low advanced/metastatic breast cancer (a/mBC): phase 1 results of a phase 1/2, open-label trial (BNT323-03) (EORTC-NCI-AACR 2026) - "Abstract will be available as of 4 November (with consent of the author)"

Clinical • Metastases • P1/2 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Safety and efficacy of DB-1303 in patients with advanced/metastatic solid tumors: A multicenter, open-label, first-in-human, phase 1/2a study. (ASCO 2023) - P1/2 | "DB-1303 was well tolerated with encouraging preliminary antitumor activity in heavily pretreated pts with advanced/metastatic solid tumors, especially in pts with HER2+ BC and brain metastasis as well as in HER2-low BC. Expansion is ongoing in selected tumor pts treated at the RP2D. Clinical trial information: NCT05150691."

Clinical • Metastases • P1/2 data • Alopecia • Anemia • Breast Cancer • Colorectal Cancer • Endometrial Cancer • Esophageal Cancer • Gastrointestinal Cancer • Hematological Disorders • HER2 Breast Cancer • Interstitial Lung Disease • Neutropenia • Oncology • Ovarian Cancer • Pulmonary Disease • Respiratory Diseases • Solid Tumor

Pumitamig + trastuzumab pamirtecan (T-Pam) in patients (pts) with HR+, HER2-low advanced/metastatic breast cancer (a/mBC): phase 1 results of a phase 1/2, open-label trial (BNT323-03) (ESMO 2026) - No abstract available

Clinical • Metastases • P1/2 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Activity of BNT327/PM8002 (PD-L1 x VEGF-A bispecific antibody) in combination with BNT325/DB-1305 (TROP2 ADC) in solid tumors: Early preclinical and clinical evidence to support BNT327 + ADC combinations (AACR 2025) - P1/2 | "Emerging data suggest that IO-ADC combinations may lead to better patient outcomes. Early clinical data showed successful dose escalation allowing enrollment to NSCLC, TNBC, ovarian, and cervical cancer expansion cohorts, with updated clinical data planned to be presented. Further evaluation is ongoing of BNT327 with ADCs against HER2 (BNT323/DB-1303), B7H3 (BNT324/DB-1311) and HER3 (BNT326/YL202), with a focus on tumors where early monotherapy efficacy has been observed with these ADCs."

ADC • Bispecific • Combination therapy • First-in-human • IO biomarker • Preclinical • Breast Cancer • Cervical Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Lung Cancer • Non Small Cell Lung Cancer • Oncology • Ovarian Cancer • Solid Tumor • Triple Negative Breast Cancer • B2M • CD276 • ERBB3 • HER-2

Trastuzumab pamirtecan (T-Pam/DB-1303/BNT323) in patients (pts) with previously treated, HER2-expressing, advanced endometrial cancer (EC): Overall survival (OS) and efficacy in pt subgroups of a phase II dose-expansion cohort (ESMO-Gynae 2026) - P1/2 | "Conclusions The efficacy of T-Pam in subgroups (race, prior lines of therapy, and prior ICI) of pts with HER2-expressing advanced/metastatic EC was comparable to that reported for the overall population. Median OS in this population was encouraging."

Clinical • IO biomarker • Metastases • P2 data • Endometrial Cancer • Gynecologic Cancers • Oncology • Solid Tumor • HER-2

Trastuzumab Pamirtecan (DB-1303/BNT323) in patients with previously treated HER2-expressing advanced/metastatic endometrial cancer: First global clinical Phase 2 data (SGO 2026) - No abstract available

Clinical • Metastases • P2 data • Endometrial Cancer • Oncology • Solid Tumor • HER-2

DB-1303-O-1001: A Phase 1/2a Study of DB-1303/BNT323 in Advanced/Metastatic Solid Tumors (clinicaltrials.gov) - P1/2 | N=796 | Recruiting | Sponsor: DualityBio Inc. | Trial primary completion date: Apr 2026 ➔ Aug 2027

First-in-human • Trial primary completion date • Oncology • Solid Tumor • HER-2

Trastuzumab pamirtecan (BNT323/DB-1303) is an ADC candidate targeting HER2 that is being developed in collaboration with Duality Biologics (Suzhou) Co. Ltd. (BioNTech Press Release) - "A Phase 3 clinical trial (DYNASTY-Breast02, NCT06018337) to evaluate trastuzumab pamirtecan in patients with HR-positive, HER2-low metastatic breast cancer is ongoing. Based on current event accrual projections, the primary analysis is expected in the fourth quarter 2026....While BioNTech and DualityBio plan to file a biologics license application ('BLA') in 2026, the companies will determine the optimal regulatory path for trastuzumab pamirtecan based on the totality of clinical data in endometrial cancer and breast cancer."

FDA filing • P3 data • Endometrial Cancer • HER2 Breast Cancer • Hormone Receptor Positive Breast Cancer

In June 2026, additional data were presented from the Phase 2 portion of the trial at the ESMO Gynaecological Cancers Congress 2026 in Copenhagen, Denmark. (BioNTech Press Release) - "Trastuzumab pamirtecan showed encouraging and durable anti-tumor activity and meaningful survival in patients with advanced HER2-expressing endometrial cancer. The safety profile was manageable and consistent with the known class effects of anti-HER2 ADCs."

P2 data • Endometrial Cancer

BNT323-03: A Clinical Study to Find the Optimal Dose of an Investigational Treatment Called BNT323 When Used in Combination With Another Investigational Treatment, BNT327, and to Test if That Combination Treatment is Safe and Beneficial for Patients With Advanced Breast Cancer (clinicaltrials.gov) - P1/2 | N=380 | Recruiting | Sponsor: BioNTech SE | Trial completion date: May 2029 ➔ Aug 2029 | Trial primary completion date: May 2028 ➔ Aug 2029

Trial completion date • Trial primary completion date • Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Dynasty-Breast01: A study comparing DB-1303 with T-DM1 in the treatment of HER2-positive unresectable/metastatic breast cancer patients who had previously received trastuzumab and taxane therapy. (clinicaltrials.gov) - P3 | N=228 | Active, not recruiting | Sponsor: Yingen Biopharmaceutical (Suzhou) Co., Ltd. | -> Active, not recruiting | Phase classification: PN/A ➔ P3

Enrollment closed • Phase classification • Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Fern-EC-01 (BNT323-01): A phase 3 trial of trastuzumab pamirtecan (HER2 ADC) versus investigator's choice of chemotherapy in patients with previously treated, HER2-expressing, recurrent endometrial cancer (EC). (ASCO 2026) - P1/2, P3 | "In Cohort 1, ≈420 patients with HER2-expressing (IHC 1+ or 2+) EC will be randomized 2:1 to evaluate the efficacy and safety of T-Pam vs investigator's choice of chemotherapy (doxorubicin, paclitaxel, or docetaxel in case of contraindication to paclitaxel and availability at the site). In Cohort 2, ≈60 patients with HER2 IHC 3+ EC will receive T-Pam; the primary endpoint for this cohort is objective response rate by BICR. Enrollment is ongoing globally."

ADC • Clinical • P3 data • Endometrial Cancer • Oncology • Solid Tumor • HER-2

A Phase 1/2 clinical trial (NCT05150691) is being conducted to evaluate trastuzumab pamirtecan in patients with advanced HER2-expressing tumors. A potentially registrational cohort with HER2-expressing (IHC3+, 2+, 1+ or ISH-positive) patients with recurrent endometrial cancer ('EC') is fully recruited. (BioNTech Press Release)

Trial status • Endometrial Cancer • HER-2

Trastuzumab pamirtecan (BNT323/DB-1303) is an ADC candidate targeting HER2 that is being developed in collaboration with Duality Biologics (Suzhou) Co. Ltd. ('DualityBio'). (BioNTech Press Release) - "BioNTech and DualityBio plan to file a biologics license application ('BLA') in 2026, subject to regulatory feedback....A global Phase 3 clinical trial (DYNASTY-Breast02, NCT06018337) to evaluate trastuzumab pamirtecan in patients with HR-positive, HER2-low metastatic breast cancer is ongoing. Based on current event accrual projections, data are expected in 2026."

FDA filing • P3 data • HER2 Negative Breast Cancer • Hormone Receptor Positive Breast Cancer

Pumitamig + Trastuzumab pamirtecan: Data from P1/2 trial (NCT06827236) for advanced breast cancer in 2026 (BioNTech) - Q1 2026 Results

P1/2 data • Breast Cancer • Oncology

Trastuzumab Pamirtecan: "49.3% confirmed ORR by IRC in patients with prior ICI treatment and central testing for HER2-expression"; Endometrial cancer (BioNTech) - Q1 2026 Results

P2 data • Endometrial Cancer • Gynecologic Cancers • Oncology

Trastuzumab pamirtecan: Data from P3 Fern-EC-01 trial (NCT06340568) for endometrial cancer in 2028 (BioNTech) - Q1 2026 Results

P3 data • Endometrial Cancer • Gynecologic Cancers • Oncology

BNT323-01: A Clinical Study of the Anti-cancer Effects of an Investigational Therapy or Chemotherapy in Patients With Recurring Uterine Cancer (clinicaltrials.gov) - P3 | N=480 | Recruiting | Sponsor: BioNTech SE

New P3 trial • Endometrial Cancer • Oncology • Solid Tumor • Uterine Cancer • HER-2

Duality Biotherapeutics said China’s National Medical Products Administration has accepted its Biologics License Application for DB-1303/BNT323 to treat adults with unresectable or metastatic HER2-positive breast cancer, following positive Phase III trial data versus T-DM1. (TipRanks)

China filing • HER2 Positive Breast Cancer

BioNTech and DualityBio’s Antibody-Drug Conjugate Trastuzumab Pamirtecan Demonstrated Clinically Meaningful Efficacy in Patients with HER2-Expressing, Recurrent Endometrial Cancer (StockTitan.net) - "BioNTech...reported positive Phase 2 results for trastuzumab pamirtecan in HER2-expressing, recurrent endometrial cancer on April 11, 2026. The cohort (n=145) showed a confirmed ORR of 47.9% in centrally tested patients and mPFS of 8.1 months, with a median DoR of 10.3 months. The safety profile was manageable; grade ≥3 TRAEs occurred in 46.9% and grade ≥3 ILD/pneumonitis in 4.8%. BioNTech and DualityBio plan a BLA filing in 2026 and an ongoing Phase 3 confirmatory trial is underway."

FDA filing • P2 data • Endometrial Cancer

Antibodies to watch in 2026. (PubMed, MAbs) - "In this installment of the series, we recap first marketing approvals granted to 19 antibody therapeutics in 2025, discuss 26 molecules currently in regulatory review, including the bispecific antibody-drug conjugate izalontamab brengitecan, and predict which molecules of the 209 currently in the commercial late-stage pipeline might transition to regulatory review by the end of 2026. Most antibody therapeutics in the latter category are for non-cancer indications (16/21, 76%) and have a conventional format (13/21, 62%), but the category also includes numerous antibody-oligo or -drug conjugates, such as delpacibart etedesiran, delpacibart zotadirsen, zeleciment rostudirsen, sonesitatug vedotin, trastuzumab pamirtecan, and ifinatamab deruxtecan, as well as the bispecific petosemtamab...Finally, to benchmark the time typically required for clinical development and regulatory review, we calculated this period for recently approved antibody therapeutic products stratified by..."

Journal • Review • Oncology

BNT323-03: A Clinical Study to Find the Optimal Dose of an Investigational Treatment Called BNT323 When Used in Combination With Another Investigational Treatment, BNT327, and to Test if That Combination Treatment is Safe and Beneficial for Patients With Advanced Breast Cancer (clinicaltrials.gov) - P1/2 | N=380 | Recruiting | Sponsor: BioNTech SE | Not yet recruiting ➔ Recruiting

Enrollment open • Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Positive Breast Cancer • Oncology • Solid Tumor • HER-2

A Study of DB-1303/BNT323 vs Investigator's Choice Chemotherapy in HER2-Low, Hormone Receptor Positive Metastatic Breast Cancer (DYNASTY-Breast02) (clinicaltrials.gov) - P3 | N=541 | Active, not recruiting | Sponsor: DualityBio Inc. | Recruiting ➔ Active, not recruiting

Enrollment closed • Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Positive Breast Cancer • Oncology • Solid Tumor • ER • HER-2 • mTOR • PGR

BNT323-03: A clinical study to find the optimal dose of an investigational treatment called BNT323 when used in combination with another investigational treatment, BNT327, and to test if that combination treatment is safe and beneficial for patients with advanced breast cancer (clinicaltrialsregister.eu) - P1/2 | N=95 | Not yet recruiting | Sponsor: BioNTech SE

New P1/2 trial • Breast Cancer • Oncology • Solid Tumor • HER-2

BNT323-01: A phase 3 trial of trastuzumab pamirtecan (HER2 ADC) versus investigator's choice of chemotherapy in pretreated patients with HER2-expressing recurrent endometrial cancer (EC) (ESGO 2026) - P1/2 | "Approximately 504 pts with previously treated HER2-expressing EC will be randomized 2:1 to receive T-Pam IV every 3 weeks, or physicians' choice chemotherapy (doxorubicin or weekly paclitaxel) until RECIST v1.1-defined progressive disease, unacceptable toxicity, or withdrawal of consent. Primary endpoint is progression-free survival (PFS) by blinded independent central review (BICR) in patients with prior ICI treatment. Secondary endpoints are PFS by BICR in all pts, overall survival (OS), PFS by investigator, ORR, duration of response, and safety.Enrollment has been initiated globally.Results NAConclusion NA"

Clinical • IO biomarker • P3 data • Endometrial Cancer • Oncology • Solid Tumor • HER-2