The FDA recently approved palbociclib plus trastuzumab, with or without pertuzumab, and endocrine therapy (ET) as a maintenance protocol for adult patients with hormone receptor (HR)-positive, HER2-positive locally advanced or metastatic breast cancer following induction treatment, according to a press release issued by the agency.

The agency approved oral palbociclib at a dosage of 125 mg for 21 consecutive days, followed by a 7-day off period.

The agency based its approval on data from the phase 3 PATINA trial, which enrolled patients with HR-positive, HER2-positive locally advanced or metastatic breast cancer. Patients enrolled in the study received induction therapy with trastuzumab and a taxane, with or without pertuzumab, and showed no evidence of disease progression at study entrance.

In the open-label study, the researchers randomly assigned patients to palbociclib plus trastuzumab, with or without pertuzumab, and ET, or to trastuzumab, with or without pertuzumab, and ET alone. ETs used in the study included fulvestrant or aromatase inhibitors. Treatment continued until confirmed disease progression or unacceptable toxicity.

Investigator-assessed progression-free survival (PFS) served as the primary endpoint, with overall survival as a secondary endpoint. Results showed a statistically significant improvement in investigator-assessed PFS among patients assigned to palbociclib plus trastuzumab, with or without pertuzumab, and ET compared with those assigned to trastuzumab, with or without pertuzumab, and ET alone.

Patients randomly assigned to palbociclib experienced a higher rate of grade 3 adverse events and grade 4 adverse events. Neutropenia was the most common treatment-emergent adverse event.

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By Cameron Kelsall

Disclosures: MD /alert could not confirm financial disclosures at the time of reporting. Alliance Foundation Trials, LLC sponsored the PATINA trial.

References:

https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-palbociclib-trastuzumab-or-without-pertuzumab-and-endocrine-therapy-maintenance

https://clinicaltrials.gov/study/NCT02947685