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Phase 1/2a Study of DB-1303/BNT323 for HER2-positive Solid Tumors

This study is testing a new treatment called DB-1303/BNT323 for people with advanced or metastatic (spread to other parts of the body) solid tumors that are HER2-positive. HER2 is a protein that can be found on some cancer cells. You might also receive other medications like Pertuzumab Injection, Ritonavir, or Itraconazole. The main goal of the first part of the study is to find a safe dose of DB-1303/BNT323 and understand its side effects. Later, the study will look at how well the treatment works. To join, you must have a HER2-positive solid tumor that has either not responded to standard treatments, caused too many side effects, or for which there are no other standard treatments available. The study is currently enrolling up to 796 participants, but its exact status is unclear.

Study design
This is a multi-center, open-label study, meaning both you and your doctors will know which treatment you are receiving. It is not randomized, except for some specific groups, and will enroll up to 796 participants.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
You would be followed for safety for approximately 35 days after treatment, and for serious side effects for about 1 year after treatment.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT05150691

A Phase 1/2a Study of DB-1303/BNT323 in Advanced/Metastatic Solid Tumors

Recruiting
PHASE1Ages 18+InterventionalTreatment
DualityBio Inc.
~796 participants
Updated 2026-08-27 on ClinicalTrials.gov
What's tested:DB-1303/BNT323Pertuzumab InjectionRitonavirItraconazole

At a glance

Recruiting sites
46 of 102 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Phase 1: Percentage of Participants with Dose-Limiting Toxicities (DLTs) as assessed by CTCAE v5.0.
Measured over up to 21 days after C1D1
+9 more outcomes measured

Conditions

HER2-positive Advanced Solid Tumor

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Where it's being run

102 sites across 61 states
Florida6
Shandong6
Zhejiang5
New York4
Jiangsu4
California3
Pennsylvania3
Anhui3

Who to contact

Britney Winterberger
[email protected]
+1-513-403-8568
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Has a pathologically documented HER2-positive or HER2-expressing (except for cohort 2h where the requirement is HER2-null), advanced/unresectable, recurrent, or metastatic malignant solid tumor that is refractory to or intolerable with standard treatment, or for which no standard treatment is available.
At least 1 measurable lesion (per RECIST 1.1)
Provide signed informed consent
ECOG performance status (PS) of 0-1.
LVEF ≥ 50% by ECHO or MUGA
Adequate organ functions
Provide pre-existing diagnosis of HER2 status or resected tumor samples or undergo fresh tumor biopsy for HER2 testing.
Life expectancy of ≥ 3 months.

Exclusion

History of symptomatic CHF (New York Heart Association \[NYHA\] classes II-IV) or serious cardiac arrhythmia requiring treatment.
History of myocardial infarction or unstable angina within 6 months before Day 1.
Average QTcF \> 450 ms in males and \> 470 ms in females
History of clinically significant lung diseases
Uncontrolled infection requiring IV antibiotics, antivirals, or antifungals.
HIV infection with AIDS defining illness or active viral hepatitis.
Clinically active brain metastases
Unresolved toxicities from previous anticancer therapy, defined as toxicities not yet resolved to NCI-CTCAE version 5.0, Grade ≤ 1 or baseline.
A known hypersensitivity to either the drug substances or inactive ingredients in the drug product.
Part 2 (expansion) Only:Multiple primary malignancies within 3 years, except adequately resected non- melanoma skin cancer, curatively treated in-situ disease, other solid tumors curatively treated, or contralateral breast cancer.

What this trial measures

  • Phase 1: Percentage of Participants with Dose-Limiting Toxicities (DLTs) as assessed by CTCAE v5.0.up to 21 days after C1D1

    Percentage of participants in Part 1 with DLTs

  • Phase 1: Percentage of participants with AEs in Part 1 graded according to NCI CTCAE v5.0Up to Safety Follow-Up visit, approximately 35 days post-treatment

    Percentage of Participants with Treatment Emergent Adverse Events (TEAEs) or Treatment Emergent Adverse Event of Special Interest include those \>/= G3 leading to dose reduction, interruption or discontinuation as assessed by CTCAE v5.0, abnormal vital signs, abnormal 12-lead ECGs, abnormal safety laboratory tests, abnormal ECOG PS, abnormal ECHO/MUGA (LVEF).

  • Phase 1: Percentage of Participants with Serious Adverse Events (SAEs) as assessed by CTCAE v5.0.Up to follow-up period, approximately 1 year post-treatment

    Percentage of Participants with SAEs in Part 1 graded according to NCI CTCAE v5.0

  • Phase 1: Maximum Tolerated Dose (MTD) of DB-1303Up to Safety Follow-Up visit, approximately 35 days post-treatment

    MTD on the data collected during Part 1

  • Phase 1: Recommended Phase 2 Dose (RP2D) of DB-1303Up to Safety Follow-Up visit, approximately 35 days post-treatment

    RP2D of DB-1303 based on the data collected during Part 1

  • Percentage of participants with AEs in Part 2 graded according to NCI CTCAE v5.0Up to follow-up period, approximately 1 year post-treatment

    Phase 2: Percentage of Participants with Treatment Emergent Adverse Events (TEAEs) or Treatment Emergent Adverse Event of Special Interest include those \>/= G3 leading to dose reduction, interruption or discontinuation as assessed by CTCAE v5.0, abnormal vital signs, abnormal 12-lead ECGs, abnormal safety laboratory tests, abnormal ECOG PS, abnormal ECHO/MUGA (LVEF).

  • Phase 2: Percentage participants with Serious Adverse Events (SAEs) as assessed by CTCAE v5.0.Up to follow-up period, approximately 1 year post-treatment

    Percentage of participants with SAEs in Part 2 graded according to NCI CTCAE v5.0

  • Phase 2: Percentage of Objective Response Rate (ORR) as assessed by RECIST 1.1.Up to follow-up period, approximately 1 year post-treatment

    The percentage of subjects who had a best response of CR or PR, for Part 2 only which was maintained ≥4 weeks.

  • Phase 2 (Dose Expansion 10 only): To evaluate the effect of ritonavir on DB-1303 and P1003 PK in subjects with HER2-expressing, HER2-amplified, or HER2-mutated advanced solid malignant tumorsup to safety follow-up visit, approx. 35 days post-treatment

    Maximum observed plasms concentration (Cmax) and Area under the concentration-time curve from 0 to infinity of DB-1303 and P1003 (+/- Ritonavir)

  • Phase 2 (Dose Expansion 10 only): To evaluate the effect of itraconazole on DB-1303 and P1003 PK in subjects with HER2-expressing, HER2-amplified, or HER2-mutated advanced solid malignant tumors.up to safety follow-up visit, approx. 35 days post-treatment

    Maximum observed plasms concentration (Cmax) and Area under the concentration-time curve from 0 to infinity of DB-1303 and P1003 (+/- Itraconazole)