Context Therapeutics (NASDAQ:CNTX) has announced preliminary Phase 2 data from the ongoing SMILE trial of onapristone extended-release (ONA-XR), the company’s novel, first-in-class, potent, orally administered progesterone receptor (PR) antagonist, in metastatic breast cancer.
Being conducted in collaboration with the Wisconsin Oncology Network, the Philadelphia-based women’s oncology company said the Phase 2 SMILE trial is evaluating ONA-XR in combination with fulvestrant in patients with ER+ (estrogen receptors), HER2- (human epidermal growth factor receptor 2) advanced or metastatic breast cancer who progressed on prior CDK4/6 inhibitor therapy.
Preliminary Phase 2 findings highlight a four-month progression-free survival (PFS) rate of 44%, and favorable safety and tolerability. The data were presented at the 2022 San Antonio Breast Cancer Symposium (SABCS).
“We are pleased to be building a robust package of data supporting the safety and tolerability of ONA-XR and its potentially meaningful improvement over single agent standards of care,” Context CEO Martin Lehr said in a statement.
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“We’re encouraged by the improvement in preliminary PFS observed in the SMILE trial presented at SABCS this week, which is consistent with the significant improvement in PFS recently reported in the ongoing Phase 2 endometrial cancer trial. We look forward to the continued evaluation of ONA-XR across multiple ongoing breast cancer clinical trials, including the SMILE and ELONA trials," he added.
Context said an initial look at the trial design of the recently initiated ELONA Phase 1b/2 clinical trial evaluating the combination of ONA-XR with The Menarini Group’s oral selective estrogen degrader, elacestrant, in patients with second- or third-line advanced or metastatic ER+, PR+, HER2- breast cancer was also presented at the symposium. Data from the Phase 1b portion of the trial is expected in the fourth quarter of 2023, it added.
The company also recently announced preliminary Phase 2 findings for ONA-XR in combination with anastrozole in progesterone receptor-positive (PR+) metastatic endometrial cancer, highlighting a four-month PFS rate of 77% and favorable safety and tolerability.
“There is a clear unmet need in metastatic endometrial cancer for a therapeutic option after primary or secondary chemotherapy treatment that can meaningfully delay disease progression without debilitating side effects prior to the next round of cytotoxic therapy,” continued Lehr.
“We believe that dual targeting of both the progesterone receptor and estrogen receptor at efficacious doses without dose-limiting toxicities could potentially result in a competitive product profile for ONA-XR. It is our hope that ONA-XR will one day address this unmet need," he concluded.
Context Therapeutics is a clinical-stage biopharmaceutical company committed to advancing medicines for female cancers. The company’s pipeline includes small molecule and bispecific antibody drug candidates that target cancer signaling pathways.
Onapristone extended-release (ONA-XR), a novel, first-in-class potent and selective progesterone receptor antagonist, is currently in three Phase 2 clinical trials and one Phase 1b/2 clinical trial in hormone-driven breast, ovarian, and endometrial cancers.
Context is also developing CTIM-76, a selective Claudin 6 (CLDN6) x CD3 bispecific antibody for CLDN6 positive tumors, currently in preclinical development.
Contact the author at stephen.gunnion@proactiveinvestors.com