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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

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BioNTech

Status and phase

Enrolling
Phase 2
Phase 1

Conditions

Unresectable Breast Carcinoma
Locally Advanced Breast Cancer
Metastatic Breast Cancer

Treatments

Drug: BNT327
Drug: BNT323

Study type

Interventional

Funder types

Industry
Other

Identifiers

NCT06827236
1011776 (Other Identifier)
2024-517979-20-00 (EU Trial (CTIS) Number)
BNT323-03

Details and patient eligibility

About

This is a Phase I/II, multi-site, open-label, two-part study designed to evaluate the efficacy, safety, optimized dose and contribution of components of BNT323 in combination with BNT327 in participants with hormone receptor-positive (HR+) or hormone receptor-negative (HR-), Human epidermal growth factor receptor (HER)2-positive, HER2-low (immunohistochemistry [IHC] 1+ or IHC 2+/in situ hybridization -), HER2-ultralow (IHC 0, with membrane staining) or HER2-null breast cancer (BC), or triple-negative breast cancer (TNBC).

Full description

The study consists of two parts:

  • Part 1 - Dose escalation: In this part of the study, participants with histologically confirmed, chemotherapy-pretreated advanced HR+, HER2-low or HER2-ultralow BC will receive BNT323 in combination with BNT327 (BNT323 + BNT327) in a dose escalation design. This will define the recommended Phase 2 dose (RP2D) for the BNT323 + BNT327 combination therapy.
  • Part 2 - Dose optimization and exploratory cohorts: This part of the study will be an expansion phase, aiming to evaluate the efficacy and safety of the optimal dose combination and providing a more robust comparison against the other treatments. It will start once the enrollment in Part 1 is completed and the sponsor in conjunction with the Safety Review Committee has assessed available Part 1 efficacy and safety data. Part 2 of the study will have four cohorts, i.e., Cohorts 1 (dose optimization cohort), and Cohorts 2, 3, and 4 (exploratory cohorts). Recruitment to Cohorts 2, 3, and 4 will begin with RP2D from Part 1 and in parallel to randomization in Cohort 1.

Randomization is planned for Cohort 1 in Part 2, i.e., participants will be randomized in 2:2:1:1 ratio into one of the four arms (RP2D of BNT323 + BNT327, lower dose of RP2D of BNT323 + BNT327, BNT323 monotherapy, and BNT327 monotherapy). No randomization is planned for any other cohort in Part 2.

Enrollment

380 estimated patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria (applicable to all participants and all parts unless otherwise specified):

  • Have pathologically documented BC that:

    • Is locally advanced, unresectable or metastatic.
    • Has a confirmed HER2 status as determined by the local laboratory (Part 1, Part 2 Cohorts 2 and 4) or the central laboratory (Part 2, Cohorts 1 and 3) from the most recently collected pre-randomization tumor sample.
    • Has a documented history of HER2 expression consistent with the subgroup definitions (i.e., HER2-low, HER2-ultralow, HER2-null, HER2-positive, or TNBC) as per current American Society of Clinical Oncology/College of American Pathologists guidelines.
  • Have measurable disease defined by RECIST v1.1.

  • Has left ventricular ejection fraction ≥55% by either echocardiography or multi-gated acquisition (scanning) within 28 days before randomization/enrollment.

Key Exclusion Criteria:

  • Have history of small bowel obstruction requiring hospitalization within the past 3 months prior to the first dose of IMP.

  • 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, peritoneal shunt, or cell-free concentrated ascites reinfusion therapy within 2 weeks prior to randomization/enrollment.

  • 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.

  • Had prior treatment with topoisomerase I inhibitors, including ADCs with topoisomerase I inhibitor payloads such as trastuzumab deruxtecan.

  • Have received any of the following therapies or drugs prior to the initiation of the study:

    • Participants who have previously been randomized to or received treatment in a previous study with BNT323, regardless of treatment assignment.
    • Participants who received prior treatment with a PD-L1/VEGF bispecific antibody. Note: Prior treatment with PD-1/VEGF bispecific antibodies, PD-1/PD-L1 inhibitors or anti-VEGF therapies are permitted.
    • Have received other systemic immunostimulatory agents or immunosuppressive therapies (such as interferon-α, interleukin-2, or methotrexate) within 4 weeks prior to the initiation of study treatment or are within five half-lives of the treatment drug (whichever is longer). Exception: excluding local, intranasal, intraocular, intra-articular or inhaled corticosteroids, short term use (≤7 days) of corticosteroids for prophylaxis (e.g., prevention of contrast agent allergy) or treatment of non-autoimmune conditions (e.g., delayed hypersensitivity reactions caused by exposure to allergens).
    • Have received systemic corticosteroids (at a dosage greater than 10 mg/day of prednisone or an equivalent dose of other corticosteroids) within 3 weeks prior to the initiation of study treatment.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Trial design

Primary purpose

Treatment

Allocation

Randomized

Interventional model

Sequential Assignment

Masking

None (Open label)

380 participants in 8 patient groups

Part1 - BNT323 + BNT327 combination therapy
Experimental group
Description:
Escalating dose levels (DLs) of BNT323 and BNT327 to define RP2D. Six DLs are planned, i.e., DL0-1, DL1-1, DL2-1, DL0-0, DL1-0, DL2-0, a combination of three different DLs for BNT323 (DL0, DL1, and DL2) and two DLs for BNT327 (DL0 and DL1).
Treatment:
Drug: BNT323
Drug: BNT327
Part 2 Cohort 1 - RP2D of BNT323 + BNT327
Experimental group
Treatment:
Drug: BNT323
Drug: BNT327
Part 2 Cohort 1 - Lower dose or RP2D of BNT323 + BNT327
Experimental group
Treatment:
Drug: BNT323
Drug: BNT327
Part 2 Cohort 1 - BNT323 monotherapy
Experimental group
Description:
BNT323 monotherapy at a fixed dose
Treatment:
Drug: BNT323
Part 2 Cohort 1 - BNT327 monotherapy
Experimental group
Description:
BNT327 monotherapy at a fixed dose
Treatment:
Drug: BNT327
Part 2 Cohort 2 - Selected dose level of BNT323 + BNT327
Experimental group
Treatment:
Drug: BNT323
Drug: BNT327
Part 2 Cohort 3 - Selected dose level of BNT323 + BNT327
Experimental group
Treatment:
Drug: BNT323
Drug: BNT327
Part 2 Cohort 4 - Selected dose level of BNT323 + BNT327
Experimental group
Treatment:
Drug: BNT323
Drug: BNT327

Trial contacts and locations

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Central trial contact

BioNTech clinical trials patient information

Data sourced from clinicaltrials.gov

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