FDA Approves Palbociclib Combo in HR+, HER2+ Metastatic Breast Cancer

Palbociclib (Ibrance) plus trastuzumab (Herceptin), with or without pertuzumab (Perjeta), and endocrine therapy has been approved by the FDA for patients with hormone receptor–positive, HER2-positive locally advanced or metastatic breast cancer after induction treatment, according to a press release from the agency.¹

Results from the phase 3 PATINA trial (NCT02947685) led to the approval.² Data showed a median progression-free survival of 44.3 months (95% CI, 32.4-56.8) in the palbociclib arm vs 29.1 months (95% CI, 23.3-38.6) for those in the standard therapy arm (HR, 0.75; 95% CI, 0.59-0.96; P = .02). The PFS rates at 48 months were 46.5% vs 38.3%, respectively.

The press release highlighted that at the time of the PFS analysis, overall survival data were not mature.

The recommended dosage of palbociclib is 125 mg orally once a day for 21 days followed by 7 days off. The prescribing information for trastuzumab, pertuzumab, and endocrine therapy should be consulted for their specific dosing.

The prescribing information for palbociclib includes warnings and precautions for neutropenia, intersitial lung disease/pneumonitis, and embryo-fetal toxicity.

Grade 3 neutropenia occurred in 55.9% of patients in the palbociclib group vs 2.0% in the standard therapy group. Additionally, grade 4 neutropenia was reported in 4.6% vs 0%. In the palbociclib group, 2 patients experienced febrile neutropenia.

“The ability to meaningfully extend [PFS] with a well-tolerated regimen offers new hope for individuals living with this challenging subtype of metastatic breast cancer,” Otto Metzger, MD, associate medical director, International Strategic Initiatives, and physician at Dana-Farber Cancer Institute; assistant professor of medicine at Harvard Medical School; and principal investigator of PATINA, said in the press release in January 2026 when PATINA results were reported.³

References

1. FDA approves palbociclib with trastuzumab, with or without pertuzumab, and endocrine therapy for the maintenance treatment of HR-positive, HER2-positive metastatic breast cancer. News release. FDA. June 24, 2026. Accessed June 24, 2026. https://tinyurl.com/mrb565fz
2. Metzger O, Mandrekar S, Goel S, et al. Palbociclib for hormone-receptor-positive, HER2-positive advanced breast cancer. N Engl J Med. 2026;394(5):451-462. doi:10.1056/NEJMoa2511218
3. Addition of CDK 4/6 inhibitor benefits patients with HR+, HER2+ metastatic breast cancer, new study shows. News release. Dana-Farber Cancer Institute. January 29, 2026. Accessed June 24, 2026. https://tinyurl.com/dvu4sj2b