Apristor®

A First-in-Class Progesterone Receptor Antagonist

ABOUT HORMONE DRIVEN CANCERS

Over 100,000 patients with metastatic breast, ovarian, prostate, or uterine cancers die per year in the United States. For many of these patients, continuous progesterone and estrogen signaling drives disease progression. Currently, only medicines that block estrogen are approved, meaning that progesterone signaling continues in those patients receiving anti-estrogen therapy.

ABOUT APRISTOR

Apristor (onapristone xr) is an investigational medicine that prevents progesterone signaling by blocking the interaction between progesterone and its binding partner, progesterone receptor. Apristor is the only known full PR antagonist. 

ROLE OF PR IN CANCER

Under normal conditions, progesterone is primarily responsible for the development of sex organs and for regulating the menstrual cycle. Cancer cells hijack progesterone to stimulate cancer cell proliferation, metastases, regeneration, and immune evasion.

LEAD INDICATION - Second Line Metastatic Breast Cancer (2L mBCa)

An estimated 40,000 patients in the United States currently have 2L mBCa. Most of these patients will have progressed on prior anti-Cdk4/6 plus antiestrogen combination therapy. Upon progression, patients exhibit a complex resistance profile that renders the current second line standard of care, Faslodex (fulvestrant), largely ineffective.

Progesterone receptor has emerged as a central resistance mechanism for up to 70% of these second line patients.

EXPANSION OPPORTUNITIES

Apristor has been evaluated in clinical trials as a monotherapy in metastatic breast, ovarian, and endometrial cancer. Context seeks to expand upon these preliminary findings via Context-sponsored or Investigator Initiated Phase 2 trials.