Initially approved in 2018, talazoparib (Talzenna®) capsules are indicated for the treatment of adult patients with deleterious or suspected deleterious germline breast cancer susceptibility gene HER2-negative locally advanced or metastatic breast cancer.
Talazoparib is a targeted agent that inhibits PARP (poly ADP-ribose polymerase) enzymes. When PARP enzymes are inhibited, tumors are unable to repair damaged DNA strands, especially tumors with defects in DNA repair mechanisms, including BRCA1 or BRCA2 mutations.
It is currently approved for the treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRDAm) HER2-negative locally advanced or metastatic breast cancer.
The initial recommended dose is 1 mg orally daily. Dose reductions are recommended for adverse effects, renal impairment, and concomitant use of certain P-gp inhibitors. Capsules are available in 1 mg and 0.25 mg dosages.
Talazoparib is given as a single oral daily dose, with or without food, taken at approximately the same time daily.
Most common side effects include bone marrow suppression (e.g., anemia, thrombocytopenia, neutropenia) and related symptoms (e.g., fatigue). Gastrointestinal side effects include nausea, vomiting, decreased appetite, and diarrhea. Patients may require antiemetic therapy. Alopecia has been reported. As with other PARP inhibitors, rare cases are reported of patients diagnosed with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) while taking talazoparib.
Dosing should be reduced in patients receiving certain P-gp inhibitors (e.g., erythromycin, carvedilol, diltiazem, ketoconazole) during concomitant therapy; consider a complete drug-drug interaction evaluation with changes in therapy. Monitor for potential increased adverse reactions to BCRP inhibitors. Talazoparib has the potential to cause embryo-fetal harm and should be avoided in pregnant women; a pregnancy test is recommended for females prior to beginning talazoparib, and females of reproductive potential must use effective contraception during treatment and for at least seven months following the last dose. Men should use effective contraception during treatment. Women should not breastfeed during treatment and for at least one month after the final dose. Monitor blood counts for potential MDS or AML.
Teach patients to swallow capsules whole, and do not cut, open, dissolve, or chew talazoparib capsules. If they miss a dose, take the next dose at the regular time. Do not take an extra dose to make up for the missed dose. Low blood cell counts are common and may need to be monitored. Women should avoid breastfeeding during and for one month after talazoparib has been stopped. Educate patients about safe drug storage and safe handling in the home.
No differences in treatment or side effects were observed when talazoparib was administered to people older than 65, 75, or 85 years.
Talazoparib has the potential for genotoxicity in humans, meeting the National Institute of Occupational Safety and Health definition of a hazardous drug. Additionally, talazoparib may cause infertility in men.
A financial assistance program is available at Talzenna’s website.