Palbociclib/Palbociclib Latest News: Zanidatamab in combination with palbociclib and fulvestrant

Zanidatamab (ZW25) in combination with palbociclib (Ibrance) and fulvestrant (Faslodex) resulted in positive progression-free survival (PFS) outcomes and demonstrated an acceptable safety profile in patients with hormone receptor-positive, HER2-positive metastatic breast cancer, according

As of 51 patients (median age, 54 years (range, 36-77 years)) in the multicenter study had received triplet therapy as of August 3, 2023, with a median follow-up of 16 months (range, 2 -32). The study's primary endpoint was 6-month progression-free survival (PFS), in 32 patients with ccHER2 In the subset of positive patients, 67% (i.e. 34 patients) and 69% (i.e. 22 patients).

Patients with metastatic disease had received an average of 4 (range, 1-12) prior systemic treatment regimens, 4 (range, 2-6) prior other HER2-targeted regimens, and 1 (range, 0-5) prior endocrine therapy.

Median PFS was 12 months (95% CI, 8-15) for all patients and 15 months (95% CI, 9-17) for the ccHER2-positive subgroup. The median duration of response was 15 months (95% CI, 12-25) for all patients and 14 months (95% CI, 11-25) for patients in the ccHER2-positive subgroup.

The disease control rate was 91% (95% CI; 79-98) and 93% (95% CI; 77-99) among all patients and the ccHER2-positive subpopulation, respectively, and the median duration of response was 15 months (95 % CI; 12-25) and 14 months (range, 11-25).

For patients with measurable disease (total 46 patients, 29 of whom were in the ccHER2-positive subset), with confirmed objective response rates of 35% (95% CI; 21-50) and 48% (95% CI; 29%-68%), respectively. For these same patients, the best confirmed objective response occurred in each group with 3 patients experiencing a complete response, 13 and 11 patients experiencing a partial response, 26 and 13 patients experiencing stable disease, and 4 and 2 patients experiencing progressive disease, respectively.

Among 29 patients with available PAM50 subtypes, the PFS6 rate was 66% and the median PFS was 9 months (95% CI; 7-14).

Trial participants had HER2-positive or HR-positive, unresectable, locally advanced or metastatic breast cancer, an ECOG performance score of 0 or 1, and at least prior treatment with trastuzumab, pertuzumab (Perjeta), and an antibody. drug conjugate trastuzumab (Kadclya) and not previously treated with a CDK4/6 inhibitor.

More than 20% of patients experienced treatment-related adverse events (TRAEs), including diarrhea (80%), neutrophil count/neutropenia (59%), nausea (39%), stomatitis (37%), anemia (29%), vomiting (25%), and fatigue (24%).

Grade 3 or higher TRAEs experienced by multiple patients included neutropenia/neutropenia (53%), diarrhea (14%), anemia (10%), thrombocytopenia (6%), hypokalemia (4%), and hypomagnesemia (4%). One serious TRAE, elevated transaminases, was also reported.

One patient discontinued all treatment due to grade 1 weakness, 2 patients discontinued palbociclib due to AEs (grade 3 diarrhea and grade 3 aminotransferase elevation), and 4 patients had their zanidumab dose reduced due to AEs. There have been 14 deaths, none of which are known to be related to treatment, 12 of which were due to disease progression, one due to COVID-19, and one of unknown cause, with causality pending.

Overall, palbociclib showed significant efficacy in the treatment of breast cancer. Although it may cause some side effects, these are predictable and manageable in most cases. Patients need to carefully observe their physical condition while taking palbociclib, and report any discomfort to their doctor immediately. On the other hand, doctors will also flexibly adjust the treatment plan based on the patient's individual differences and drug response, and provide professional medication guidance to ensure the safety and effectiveness of the treatment.