FDA approved Talzenna (talazoparib) for Germline BRCA-Mutated HER2-Negative Breast CancerFDA approved Talzenna, a Daily Pill for Some Inherited Breast Cancers

Talzenna is a poly (ADP-ribose) polymerase (PARP) inhibitor. The label states this mechanism but does not provide further details on the specific PARP enzymes inhibited or the precise mechanism of action.

Talzenna is indicated as a single agent for the treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm) HER2-negative locally advanced or metastatic breast cancer. Patients should be selected for therapy based on an FDA-approved companion diagnostic for Talzenna. The label also includes an indication in combination with enzalutamide for HRR gene-mutated metastatic castration-resistant prostate cancer (mCRPC), but this article focuses on the breast cancer indication.

The recommended dosage of Talzenna for gBRCAm HER2-negative locally advanced or metastatic breast cancer is 1 mg taken orally once daily until disease progression or unacceptable toxicity. Talzenna may be taken with or without food. Capsules should be swallowed whole and must not be opened or dissolved. If a patient vomits or misses a dose, the next prescribed dose should be taken at the usual time. For adverse reactions, treatment interruption with or without dose reduction may be considered based on severity and clinical presentation. The recommended dose reduction levels for breast cancer are: first reduction to 0.75 mg once daily, second reduction to 0.5 mg once daily, and third reduction to 0.25 mg once daily. Treatment should be discontinued if more than 3 dose reductions are required. Complete blood counts should be monitored monthly and as clinically indicated. For patients with moderate renal impairment (CLcr 30-59 mL/min), the recommended dosage is 0.75 mg once daily. The label also provides dosing for severe renal impairment, but the text is truncated.

Trial data not available in label.

The label includes warnings and precautions regarding hematologic toxicities. Monitoring of complete blood counts is recommended. Dose modification and management guidelines for adverse reactions are provided: for hemoglobin <8 g/dL, withhold Talzenna until levels resolve to ≥9 g/dL, then resume at a reduced dose; for platelet count <50,000/μL, withhold until ≥75,000/μL; for neutrophil count <1,000/μL, withhold until ≥1500/µL; for non-hematologic Grade 3 or Grade 4 adverse reactions, withhold until ≤Grade 1, then consider resuming at a reduced dose or discontinue. Contraindications are not specified in the provided label text.

The label positions Talzenna as a single-agent oral therapy for adult patients with gBRCAm HER2-negative locally advanced or metastatic breast cancer, selected by an FDA-approved companion diagnostic. It is a PARP inhibitor, a class of drugs used in BRCA-mutated cancers. The label does not provide comparative efficacy data or information on sequencing relative to other therapies.