A Phase I/IIA Study of DB-1303 in People with Advanced Endometrial Cancer or Endometrial Carcinosarcoma


Full Title

A Phase 1/2a, Multicenter, Open-Label, First in Human Study to Assess the Safety, Tolerability, Pharmacokinetics, and Preliminary Antitumor Activity of DB-1303/BNT323 in Patients with Advanced/Metastatic Solid Tumors


The purpose of this study is to assess the safety of the investigational drug DB-1303 in people with advanced endometrial cancer or endometrial carcinosarcoma that has come back or continued to grow despite treatment and makes a protein called HER2, which helps cancer cells grow and survive.

DB-1303 is a type of drug called an “antibody-drug conjugate.” It is made up of an antibody and a chemotherapy drug. DB-1303 attaches to the HER2 protein on cancer cells. Then the chemotherapy drug enters the cells and kills them, preventing tumor growth. DB-1303 is given intravenously (by vein).

Who Can Join

To be eligible for this study, patients must meet several requirements, including:

  • Participants must have HER2-positive endometrial cancer or endometrial carcinosarcoma that has come back or continues to grow despite treatment.
  • The serious side effects of previous therapies must go away before DB-1303 is given.
  • Patients must be physically well enough that they are able to be mobile, take care of themselves, and engage in all but physically strenuous activities. For example, they must be well enough that they could carry out office work or light housework.
  • This study is for people age 18 and older.


For more information and to ask about eligibility for this study, please contact the office of Dr. Vicky Makker at 646-888-4224.




Phase I/II (phases 1 and 2 combined)

Disease Status

Relapsed or Refractory



ClinicalTrials.gov ID