The PHERGain clinical trial, developed by MEDSIR – a company dedicated to promoting independent clinical research in oncology internationally – has been published in the prestigious journal The Lancet, following positive results showing that one-third of patients with localized HER2-positive breast cancer can be cured without requiring chemotherapy, drastically reducing side effects.

This study marks a milestone by using an adaptive design to personalize treatment in the neoadjuvant/adjuvant setting for patients with localized HER2-positive breast cancer. The main goal was to evaluate the feasibility of an adaptive therapeutic strategy based initially on exclusive treatment with dual HER2 blockade using trastuzumab and pertuzumab, with the addition of chemotherapy based on early response observed by PET-CT and complete pathological response.

The trial was led by MEDSIR researchers Dr. Javier Cortés, Dr. Antonio Llombart-Cussac, and Dr. José Pérez. “The results of this study bring us closer to the end of chemotherapy in a significant percentage of patients with this type of tumor,” says Dr. Javier Cortés, the principal investigator of the study.

The initial results of the PHERGain clinical trial showed that early assessment of response to exclusive preoperative treatment without chemotherapy based on trastuzumab and pertuzumab, using PET-CT, could identify around 40% of patients with localized HER2-positive breast cancer who achieved a complete pathological response. These positive results were published in the journal Lancet Oncology in 2021.