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Study of MT-5111 in HER2-positive Solid Tumors

Trial Status: Active

This will be a Phase 1, first in human, open-label, dose escalation and expansion study of MT-5111 (a recombinant fusion protein) in subjects with HER2-positive solid tumors.

Inclusion Criteria

  • Histologically confirmed, unresectable, locally advanced or metastatic solid cancers:
  • Part 1 (Dose-Escalation): All HER2-positive solid cancers are eligible
  • Part 2 (Dose-Expansion): Any type of HER2-positive solid cancer, including breast cancer, gastric or gastroesophageal adenocarcinomas (GEA).
  • HER2-positive in the latest tumor sample tested for HER2 (testing to be done on a metastatic lesion in cases of metastatic cancers).
  • Relapsed or refractory to or intolerant of existing therapy(ies)
  • At least 1 measurable or evaluable lesion according to RECIST 1.1
  • ECOG performance score of ≤ 1
  • Bone marrow function:
  • Absolute neutrophil count (ANC) ≥ 1,000/mm3
  • Platelet count ≥ 75,000 mm³ and
  • Hemoglobin ≥ 8.0 g/dL
  • No red blood cell transfusion within 4 weeks of study treatment start is allowed
  • Kidney function:
  • (eGFR) ≥ 50 mL/min calculated by the Cockcroft-Gault formula
  • Subjects with CLcr ≥ 50 mL/min will be eligible irrespective of the eGFR result
  • Cardiac Function:
  • Left ventricular ejection fraction (LVEF) ≥ 55% on the multigated acquisition (MUGA) scan (preferred) or echocardiogram (ECHO) assessment, and
  • QTcF ≤ 480 ms for women and QTcF ≤ 450 ms for men [average from three QTcF values on the triplicate 12-lead electrocardiogram (ECG)] at baseline
  • Hepatic function:
  • Total bilirubin ≤ 1.5 x ULN, and
  • AST ≤ 3 x ULN and ALT ≤ 3 x ULN
  • < 5 x ULN (if hepatic metastases)

Exclusion Criteria

  • History or current evidence of another tumor that is histologically distinct from the tumor under study
  • Current evidence of new or growing CNS metastases during screening -Subjects with known CNS metastases will be eligible if they meet specified criteria
  • Evidence of CTCAE Grade >1 toxicity before the start of treatment, except for hair loss and those Grade 2 toxicities listed as permitted in other eligibility criteria
  • History or evidence of significant cardiovascular disease
  • Current evidence of active, uncontrolled hepatitis B virus, hepatitis C virus, human immunodeficiency virus (HIV) (evidenced by detectable viral load by PCR) or acquired immunodeficiency syndrome (AIDS) related illness
  • Current evidence of ≥ grade 2 underlying pulmonary disease
  • Certain exclusionary prior treatments


Mayo Clinic in Arizona
Status: ACTIVE


Los Angeles
UCLA / Jonsson Comprehensive Cancer Center
Status: ACTIVE
Contact: Kim Kelly
Phone: 310-206-8309


Mayo Clinic in Florida
Status: ACTIVE
University of Miami Miller School of Medicine-Sylvester Cancer Center
Status: ACTIVE


University of Chicago Comprehensive Cancer Center
Status: ACTIVE


Mayo Clinic in Rochester
Status: ACTIVE


Saint Louis
Siteman Cancer Center at Washington University
Status: ACTIVE


San Antonio
Cancer Therapy and Research Center at The UT Health Science Center at San Antonio
Status: ACTIVE
Contact: Sonia Lisa Creighton
Phone: 210-450-1366

This study will be conducted in two sequential parts:

- Part 1 (Dose Escalation): The purpose of Part 1 is to determine the Phase 2 dose (RP2D)

to be used in Part 2. Part 1 will include any type of HER2-positive solid cancer.

- Part 2 (Dose Expansion): The purpose of Part 2 is to confirm the safety and tolerability

of the RP2D of MT-5111. Part 2 will include any type of HER2-positive solid cancer,

including breast cancer, gastric or gastroesophageal adenocarcinomas (GEA).

Up to 140 eligible subjects will be identified and treated through competitive enrollment at

multiple study centers.

In Parts 1 and 2 of the study, a subject may participate for the following four periods:

- Screening (up to 28 days before first dose of MT-5111)

- Treatment period (active period where a subject will receive doses of MT-5111 over a

21-day treatment cycle)

- Follow-up (30 days after last dose of MT-5111)

- Long-term follow-up (up to 24 months after the last dose of MT-5111)

MT-5111 will be given as an intravenous (IV) infusion over about 30 minutes on the same day

every week (i.e., on day 1, day 8 and day 15 of each cycle, a cycle being defined as 21

days). A subject can continue receiving MT-5111 as long as it is well-tolerated, their

disease has not worsened, or until the subject decides they no longer want to participate in

the study.

Trial Phase Phase I

Trial Type Treatment

Lead Organization
Molecular Templates, Inc.

  • Primary ID MT-5111_001
  • Secondary IDs NCI-2019-05158
  • ID NCT04029922