Dr Tarantino on De-Escalated THP With/Without Carboplatin in HER2+ Breast Cancer

“[These data] were impressive because we would have expected the carboplatin to add [to the efficacy of THP]. Instead, in the setting of HER2 blockade, it doesn’t seem to add much.”

Paolo Tarantino, MD, PhD, a research fellow in the Department of Medicine at Dana-Farber Cancer Institute and Harvard Medical School, discussed findings from the phase 3 neoCARHP trial (NCT04858529) in patients with HER2-positive early breast cancer.

neoCARHP compared neoadjuvant taxane therapy in combination with carboplatin, trastuzumab (Herceptin), and pertuzumab (Perjeta; TCHP) vs a taxane plus trastuzumab and pertuzumab (THP), Tarantino began. Findings from the study, which were presented during the 2025 ASCO Annual Meeting, demonstrated that the pathologic complete response (pCR) rate among patients who received THP (n = 382) was 64.1% compared with 65.9% in the TCHP arm (n = 384), representing a difference of only –1.8% (95% CI, –8.5% to 5.0%; P = .0089), he said. These data were notable because investigators expected the TCHP arm to have a positive effect on pCR rate, but in the setting of HER2 blockade, it did not, he noted.

Recurrence-free survival (RFS) findings have not yet fully matured, but the pCR rate that was observed with THP alone was promising, Tarantino said. Regarding safety, THP was well tolerated. Although peripheral neuropathy remains a concern, the omission of carboplatin led to much less hematologic toxicity, he added.

These data, together with findings from the phase 2 CompassHER2 pCR trial (NCT04266249), suggest that carboplatin can be omitted from the treatment regimen for patients with stage II HER2-positive breast cancer, Tarantino explained. However, this approach has not yet been confirmed for patients with stage III disease because overall survival and RFS data are not yet available, he noted. As these data become available over the coming years, they have the potential to change practice for the treatment of patients with HER2-positive breast cancer, he concluded.