Antibody-drug conjugate MORAb-202 exhibits long-lasting antitumor efficacy in TNBC PDx models

Keiji Furuuchi1, Katherine Rybinski1, James Fulmer1

  • 1Epochal Precision Anti-Cancer Therapeutics (EPAT), Eisai Inc, Exton, PA, USA.

Cancer Science
|March 23, 2021
PubMed

Insights

The investigational antibody-drug conjugate MORAb-202 shows promise for treating triple-negative breast cancer (TNBC). It effectively targets folate receptor alpha (FRA)-positive tumors with minimal off-target effects and demonstrates durable antitumor efficacy in preclinical models.

Area of Science:

  • Oncology
  • Pharmacology
  • Biotechnology

Background:

  • Folate receptor alpha (FRA) is overexpressed in several cancer types, making it a target for cancer therapies.
  • Antibody-drug conjugates (ADCs) offer targeted delivery of cytotoxic agents to cancer cells.

Purpose of the Study:

  • To evaluate the preclinical efficacy and safety of MORAb-202, an ADC targeting FRA.
  • To assess MORAb-202's in vitro and in vivo activity, including its bystander effect and toxicity profile.

Main Methods:

  • In vitro cytotoxicity assays on FRA-positive and FRA-negative cells.
  • Coculture experiments to evaluate bystander effect.
  • In vivo antitumor efficacy studies in triple-negative breast cancer (TNBC) patient-derived xenograft (PDx) models.
  • Toxicology studies in nonhuman primates.

Main Results:

  • MORAb-202 demonstrated high in vitro cytotoxicity against FRA-positive cells with limited off-target effects.
  • A significant in vitro bystander cytotoxic effect was observed.
  • MORAb-202 exhibited durable, dose-dependent antitumor efficacy in TNBC PDx models.
  • Hematologic toxicity was identified as the primary concern in nonhuman primate toxicology studies.

Conclusions:

  • MORAb-202 is a potent ADC targeting FRA, showing promising preclinical efficacy in TNBC models.
  • The observed efficacy and manageable toxicity profile support further investigation of MORAb-202 for TNBC treatment.