Recruiting
Phase 3

BNT323 vs. Chemotherapy

Sponsor:

BioNTech SE

Code:

NCT06340568

Conditions

Endometrial Cancer

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Interventions

BNT323/DB-1303

Doxorubicin

Paclitaxel

Docetaxel

Study Details

Brief summary:

The study is divided into two cohorts (Cohort 1 and Cohort 2), to which participants will be enrolled based on the amount of human epidermal growth factor receptor 2 (HER2) in their tumor sample.

In Cohort 1, the main goal is to assess how well BNT323 (also known as DB-1303) or chemotherapy (doxorubicin or paclitaxel \[or docetaxel, if participants cannot take paclitaxel\]) works by determining the progression-free survival (PFS) of participants who have been previously treated with immune checkpoint inhibitors (ICIs).

In Cohort 2, the main goal is to assess how well BNT323 works by determining the objective response rate (ORR), that is, the percentage of participants whose tumor shrinks (partial response) or disappears (complete response) after treatment.

The safety of BNT323 will also be assessed by following the occurrence of unfavorable/adverse effects that are seen after treatment. Other measures include the pharmacokinetics of BNT323 (or how BNT323 moves through and out of the body), the body's immune response, and the impact on quality of life.

Conditions

Endometrial Cancer

Study ID

NCT06340568

Start date

Jun 10, 2025

Status verified date

Aug, 2026

Completion date

Nov, 2029

Anticipated

Primary completion date

Mar, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Are female adults (defined as ≥18 years of age or acceptable age according to local regulations at the time of voluntarily giving informed consent).
  • Have histologically confirmed endometrial cancer that:

  • Is recurrent,
  • Has a HER2 IHC score of 1+, 2+ (Cohort 1), or 3+ (Cohort 2) as determined by central laboratory testing for HER2 expression, and
  • Is not defined as a true sarcoma (i.e., leiomyosarcoma or endometrial stromal sarcoma). Note: Uterine carcinosarcoma is allowed.
  • Have measurable disease defined by RECIST v1.1.
  • Have Eastern Cooperative Oncology Group (ECOG) Performance Status of 0, 1 or 2.
  • Have recurrent endometrial cancer and meet any of the following:

  • developed recurrence <12 months from completing platinum-based chemotherapy given as adjuvant therapy for Stage I to III disease, or
  • developed recurrence after platinum-based chemotherapy in the recurrent/metastatic setting.
  • Have received prior ICI treatment (i.e., anti-programmed death 1/anti-programmed death-ligand 1)
  • Have a life expectancy of ≥12 weeks at screening.

Key Exclusion Criteria:

  • Are ineligible for all options in the investigator's choice of chemotherapy arm, per local prescribing information and institutional guidelines (applicable to Cohort 1 only).
  • Have a history of small bowel obstruction requiring hospitalization within the past 3 months prior the first dose of study treatment.
  • Have an uncontrolled intercurrent illness that would limit compliance with study requirement or substantially increase risk of incurring adverse events.
  • Have clinically uncontrolled pleural effusion, ascites or pericardial effusion requiring drainage, or peritoneal shunt within 2 weeks prior to the first dose of study treatment.
  • Have a history of (non-infectious) interstitial lung disease (ILD)/pneumonitis that required steroids, have current ILD/pneumonitis, or where suspected ILD/pneumonitis cannot be ruled out by imaging at screening.
  • Participants with prior use of immunosuppressive medication within 14 days prior to the first dose of study treatment, except for intranasal and inhaled corticosteroids or systemic corticosteroids at doses of less than 10 mg/day of prednisone or equivalent, and topical corticosteroids. Participants receiving corticosteroids may continue if the dose is stable upon giving main informed consent.
  • Have a lung-specific intercurrent clinically significant illness including, but not limited to, any underlying pulmonary disorder (e.g., pulmonary emboli within 3 months prior to the first dose of study treatment, severe asthma, chronic obstructive pulmonary disorder with moderate acute exacerbations, restrictive lung disease, pulmonary fibrosis, radiation pneumonitis, significant pleural effusion etc.), or any autoimmune, connective tissue or inflammatory disorder with pulmonary involvement (i.e., rheumatoid arthritis, Sjogren's syndrome, sarcoidosis etc.), and/or prior pneumonectomy (complete).
  • Have uncontrolled infection requiring systemic antibiotics, antivirals, or antifungals within 2 weeks prior to the first dose of study treatment.
  • Have unresolved toxicities from previous anti-cancer therapy, defined as toxicities (other than alopecia, fatigue, or endocrinopathies that are well controlled) not yet resolved to Grade ≤1 or baseline.
  • Are pregnant or breastfeeding or are planning pregnancy during the study or within 7 months after the last dose of study treatment.
  • Have a history of allergies, hypersensitivities, or intolerance to study treatments (investigational medicinal products and auxiliary medicinal product) including any excipients thereof or to other monoclonal antibodies. Participants who have successfully undergone a desensitization process and are able to tolerate the drug are eligible.
  • Had prior treatment with topoisomerase I inhibitors, including ADCs.
  • Have left ventricular ejection fraction <55% by either echocardiography or multiple-gated acquisition within 28 days prior to the first dose of study treatment. This includes participants with tissue doppler E/e' ratio >15.

NOTE: Other protocol defined Inclusion/Exclusion criteria apply.

Study Design

Enrollment

480 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Cohort 1 (HER2 IHC score 1+ or 2+): BNT323/DB-1303

active comparator: Cohort 1 - Doxorubicin or paclitaxel (or docetaxel)

Single agent chemotherapy (either doxorubicin or paclitaxel) per investigator's choice. Participants with contraindications to paclitaxel may receive docetaxel as an alternative (if available at the site).

experimental: Cohort 2 (HER2 IHC score 3+) - BNT323/DB-1303

Interventions

BNT323/DB-1303

intravenous (IV) infusion

Doxorubicin

IV bolus or infusion

Paclitaxel

IV infusion

Docetaxel

IV infusion

Primary outcome measure

  • Cohort 1: PFS assessed by blinded independent central review (BICR) in participants with HER2 IHC 1+/2+ recurrent endometrial cancer [ Time Frame: Up to approximately 53 months ]
  • Cohort 2: ORR assessed by BICR in participants with HER2 IHC 3+ recurrent endometrial cancer [ Time Frame: Up to approximately 53 months ]

Central Contacts and Locations

Central contacts

BioNTech clinical trials patient information

+49 6131 9084patients@biontech.de

Locations

Yale University School of Medicine

Recruiting

New Haven, Connecticut, United States, 06520

MedStar Washington Hospital Center

Recruiting

Washington D.C., District of Columbia, United States, 20010

Broward Health Medical Center

Recruiting

Fort Lauderdale, Florida, United States, 33316

OSF Saint Francis Medical Center

Recruiting

Peoria, Illinois, United States, 61637

Carle Cancer Institute

Recruiting

Urbana, Illinois, United States, 61801

WK Cancer Center

Recruiting

Shreveport, Louisiana, United States, 71103

The Center of Hope Reno

Recruiting

Reno, Nevada, United States, 89511

NYU Langone Hospital - Long Island

Recruiting

Mineola, New York, United States, 11501

NYU Langone Health

Recruiting

New York, New York, United States, 10016

SUNY Upstate Medical University

Recruiting

Syracuse, New York, United States, 13210

Miami Valley Hospital South

Recruiting

Centerville, Ohio, United States, 45459

Ohio State University

Recruiting

Hilliard, Ohio, United States, 43026

Peggy & Charles Stephenson Oklahoma Cancer Center

Recruiting

Oklahoma City, Oklahoma, United States, 73104

Sanford Cancer Center

Recruiting

Sioux Falls, South Dakota, United States, 57104

Jewish General Hospital

Recruiting

Montreal, Canada, H3T 1E2

Health Sciences Centre

Recruiting

St. John's, Canada, A1V 3V6

Princess Margaret Cancer C

Recruiting

Toronto, Canada, M5G 2M9

More Information

Sponsor

BioNTech SE

Last update posted

Sep 1, 2026

Last verified

Aug, 2026

Keywords

  • Human epidermal growth factor receptor 2 (HER2)
  • HER2-expressing tumors
  • Recurrent endometrial cancer
  • IHC scores 1+, 2+, and 3+
  • Immune checkpoint inhibitor
  • Platinum-based therapy
  • HER2 protein expression
  • HER2-expressing endometrial cancer
  • ErbB-2 receptor
  • Antibody drug conjugate (ADC)

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by BioNTech SE on 2026-09-01.