Talzenna-Novel Drug Combo Continues to Be Studied in Patients With Triple-Negative Breast Cancer

After results from a phase 1b/2 trial showed that treatment with Talzenna (talazoparib) plus ZEN-3694 was well tolerated and elicited a clinical benefit in a group of patients with triple-negative breast cancer, Zenith Epigenetics, the manufacturer of ZEN-3694, announced it would initiate an extension of the initial trial.

The phase 2b portion of the trial, according to a company-issued press release, will enroll patients who have previously been treated with a Trophoblast cell surface antigen 2 (TROP2) antibody drug conjugate for locally advanced or metastatic disease.

“The data from the phase 1b/2 trial has shown that the ZEN-3694 plus (Talzenna) combination regimen induced durable responses in tumors of (triple-negative breast cancer) patients which do not harbor mutations in BRCA1/2,” lead study author Dr. Mark Robson, a medical oncologist at The Memorial Sloan Kettering Cancer Center in New York City, said in the release. “These clinical results confirm the rationale and data from pre-clinical experiments which have shown that BET inhibition can sensitize wild type BRCA1/2 TNBC tumors to PARP inhibition. This interesting data warrants the continued clinical evaluation of this combination.”

In 2018, the Food and Drug Administration (FDA) approved Talzenna as a monotherapy for the treatment of patients with deleterious or suspected deleterious germline BRCA-mutant, HER2-negative locally advanced or metastatic breast cancer.

The findings of the phase 3 EMBRACE trial, which led the agency to approve Talzenna, had demonstrated that treatment with the study drug resulted in an average progression-free survival (time to disease progression or death) of 8.6 months compared with 5.6 months in those who had received standard chemotherapy.

In this phase 2b trial, researchers will continue to analyze the safety and efficacy of Talzenna in combination with ZEN-3694 in patients with locally advanced or metastatic germline wild type BRCA1/2 triple-negative breast cancer.

“There is a significant unmet need in this aggressive cancer with few non-cytotoxic therapy options available for the patient,” Donald J. McCaffery, president and CEO of Zenith, said in the release.

The data from the completed portion of this trial, according to the release, will be presented at an upcoming medical conference in Chicago.

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