ZENITH Epigenetics has commenced a Phase IIb clinical trial of a combination of its ZEN-3694 with Pfizer’s Talzenna (talazoparib) to treat patients with triple-negative breast cancer (TNBC).

A lead compound of the company, ZEN-3694 is being developed for several oncologic indications.

The trial will assess the safety and efficacy of the combination therapy in people who have locally advanced or metastatic germline wild type BRCA1/2 TNBC. 

It will enrol subjects who have previously received a TROP2 antibody-drug conjugate for locally advanced or metastatic disease.

This trial is an expansion of the lately concluded Phase Ib/II trial.

The Phase Ib/II trial had met the primary efficacy endpoint of clinical benefit rate including objective responses and stable disease.

Furthermore, the combination treatment was found to be well tolerated in the trial.

Data from this concluded trial will be presented on 6 June this year.

Zenith Epigenetics president and CEO Donald McCaffery said: “We are very pleased to advance our TNBC programme to Phase IIb and closer to possible registration. 

“There is a significant unmet need in this aggressive cancer with few non-cytotoxic therapy options available for the patient”.

Apart from the Phase IIb trial, ZEN-3694 is being analysed along with Xtandi (enzalutamide) in a Phase IIb trial for metastatic castration-resistant prostate cancer.

In addition, a Phase Ib/II trial of ZEN-3694 plus Keytruda (pembrolizumab) and Xtandi for androgen receptor-independent mCRPC and a Phase Ib/II ovarian cancer trial of ZEN-3694 plus nivolumab and ipilimumab are underway.

An inhibitor of poly (ADP-ribose) polymerase (PARP), talazoparib is approved for usage in the US under the brand name Talzenna.

It is intended to treat adults with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm) HER2-negative locally advanced or metastatic breast cancer.