Up until a few years ago, medicine had focused on researching and developing therapeutic solutions that could give answers to the needs of as many patients as possible.
Nowadays, thanks to advances in research and innovation, which are solving the mysteries surrounding human genome and the origin of each tumor, and also thanks to new and increasingly precise diagnostic technologies and localized treatment, a new era begins in which medicine is specializing in giving answers to the specific needs of each patient.
This is the main goal of the PHERgain study started and led from MEDSIR alongside an ecosystem of collaborative partners: to prove that a de-escalation in the use of chemotherapy is possible in HER-2 positive (HER2+) breast cancer treatment, thus reducing the side effects and toxicity of the treatment and improving life quality for patients.
HER2+ breast cancer represents 15-20% of all diagnosed breast cancer tumors. It is characterized by an increased expression in a protein called HER2, which also increases its aggression and the likelihood of developing metastases from these tumors. Patients diagnosed with localized HER2+ breast cancer systematically receive treatment consisting of a combination of chemotherapy and HER2-targeted therapies that specifically block this protein (trastuzumab and pertuzumab).
Chemotherapy is very effective in killing cancer cells, but is also associated with high toxicity and secondary effects, as it also damages other healthy cells. Treatment strategies without chemotherapy, for example trastuzumab or pertuzumab, can stop, prevent and slow the growth of cancer cells with fewer side effects.
The PHERGain study involved researchers from 45 centers located in seven European countries and included a total of 356 patients with localized HER2+ breast cancer. The obtained results have been very promising, because they not only prove that some patients can be safely and effectively treated without chemotherapy, but they also show that adaptive trial designs are beneficial, highlighting the importance of designing strategic and innovative trials that are of clinical interest to patients.
According to PHERgain results presented during the international ASCO 2023 Congress in Chicago last June, a therapeutic strategy based on PET-CT and pathological response could identify around 30% of patients with localized HER2+ breast cancer who could be safely spared chemotherapy treatment. Furthermore, the study shows that 95.4% of all patients that followed this treatment strategy remain cancer-free after 3 years of follow-up.
The PHERGain study is of great importance for several reasons. Firstly, it is a pioneer study that gradually adjusts each patient’s treatment according to how she responds to therapy, which represents an advance towards a more personalized medicine that is based on the global participation of the collaborator ecosystem. Unlike usual clinical trials where two treatment arms are compared, the PHERGain study design focuses on determining each patient’s response to the treatment and adapting their care according to their individual needs.
In addition, this trial lays the groundwork for future studies that seek to develop more precise prognostic tools, with the goal of better identifying localized HER2+ breast cancer patients that could safely avoid chemotherapy treatment.
In the end, the positive results not only prove the chance of treating some patients safely and efficiently without chemotherapy, they also support the value of adaptive trial designs and their use whenever they are feasible. These designs allow professionals to adjust treatments in a dynamic way according to the individual response of each patient, something that could significantly improve clinical results and open up new perspectives in the field of HER2+ breast cancer treatment.
MEDSIR
