Newswise — JERSEY CITY, N.J.June 2, 2023 /PRNewswire/ -- MEDSIR announced today the positive results of the PHERGain trial. This study is the first to use an adaptive design that tailors treatment in the neoadjuvant/adjuvant setting of patients with HER2-positive early breast cancer. The main objective of this trial was to assess the feasibility of a chemotherapy-free strategy based on a dual HER2 blockade with trastuzumab and pertuzumab through a positron emission tomography (PET)-based, pathologic complete response response(pCR)-adapted strategy.

MEDSIR PHERGain trial is the first to use an adaptive design in HER2-positive early breast cancer. 

PHERGain is a randomized, controlled phase 2 clinical trial that involved 356 early-stage HER2-positive breast cancer patients from 45 centers in seven European countries. It was sponsored by MEDSIR, a company dedicated to advancing clinical research in oncology, and led by scientific investigators Dr. Javier Cortés, Dr. Antonio Llombart-Cussac, and Dr. José Pérez. The first primary endpoint was the pCR rate in patients with PET response included in group B, whose positive results were published in 2021 in Lancet Oncology.

The results of the second primary endpoint, 3-year invasive disease-free survival in all patients assigned to group B, have been presented at the 2023 American Society of Clinical Oncology (ASCO) congress. Overall, 95.4% of patients who followed this chemotherapy de-escalation strategy using PHERGain's adaptive design remained cancer-free after three years of follow-up from breast cancer surgery. This is especially relevant because around 30% of these patients did not receive chemotherapy without compromising patient's outcome. Among this latter group, 98.9% remained cancer-free after three years of follow-up from breast cancer surgery.

"This study offers a potential future therapeutic option that enables a significant reduction of toxicity and an improvement in quality of life for this patient population without reducing efficacy", explains Dr. Cortés. In addition, the most relevant finding "is that 99% of the subgroup who received anti-HER2 therapy without chemotherapy have not presented a recurrence of the disease after three years of follow-up".

"These results bring us closer to the end of chemotherapy in a significant percentage of patients with this type of tumor," explains Dr. Llombart-Cussac, "It is critical to design more efficient strategy-based clinical trials with adaptive designs to bring effective therapies to patients in the shortest amount of time."


Founded in 2012, MEDSIR works closely with its partners to drive innovation in oncology research. Based in Spain and the United States, the company manages all aspects of clinical trials, from study design to publication, utilizing a global network of experts and integrated technology to streamline the process. The company offers proof-of-concept support and a strategic approach that helps research partners experience the best of both worlds from industry-based clinical research and investigator-driven trials. To promote independent cancer research worldwide, MEDSIR has a strategic alliance with Oncoclínicas, the leading oncology group in Brazil with the greatest research potential in South America. Learn how MEDSIR brings ideas to life:

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2023 American Society of Clinical Oncology (ASCO) Congress