What if it were soon possible to eradicate gestational trophoblastic tumors? This is the hope raised by a recent Lyon study according to which a new therapeutic combination combining chemotherapy and immunotherapy would make it possible to cure 96% of patients. Focus on the conclusions of this unprecedented study.
What are gestational trophoblastic tumors?
Affecting less than 200 women per year in France, gestational trophoblastic tumors designate rare tumors that grow inside the placenta during pregnancy. They manifest themselves by bleeding during pregnancy and an abnormally high level of hCG (human chorionic gonadotropic hormone) in patients. Visible on ultrasound, 80% of these tumors are considered low risk because they are located in the uterus. Others are metastatic in the lungs but have a favorable prognosis.
To know! In rare cases, a gestational trophoblastic tumor may develop after a normal delivery and be classified as “high risk.”
Regarding the treatment classically administered to patients with this type of tumor, it is based on chemotherapy based on methotrexate with a cure rate of 70%.
Based on this observation, Lyon researchers from the Lyon Sud hospital (Hospices Civils de Lyon) wanted to check if it was possible to improve this healing rate by means of a new therapeutic combination combining classic chemotherapy with immunotherapy.
A new, unprecedented therapeutic combination
To carry out their work, the Lyon scientists called on the national network of the Lyon Sud Reference Center for Trophoblastic Diseases to recruit 26 patients in nine French health establishments specializing in early phase clinical trials in gynecology.
This is how, between the end of 2020 and the end of 2023, the participants in this study were administered a unique therapeutic combination combining chemotherapy and immunotherapy with :
- One methotrexate injection every other day for a week, every two weeks.
- An injection of avelumab (an anti-PDL-1 monoclonal antibody) every two weeks.
To know! Avelumab is a human immunoglobulin G1 monoclonal antibody directed against the programmed death protein 1 (PD-L1) ligand. By binding to PD-L1, avelumab blocks the interaction between PD-L1 and its receptors, PD-1 (programmed death protein 1) and B7.1. This blockade induces the suppression of the inhibitory effects of PD-L1 on cytotoxic CD8+ T lymphocytes, and therefore restores the anti-tumor responses of T lymphocytes.
During follow-up, each participant then had their hCG levels checked every week. If it was abnormally high, it means the disease was still active. On the other hand, when the hCG level normalized, the patient repeated six weeks of treatment before stopping it completely.
Towards a definitive treatment of gestational trophoblastic tumors?
Presented at the annual congress of the European Society of Medical Oncology (Esmo) on September 14 in Barcelona, the results of this study should delight its authors. Those who hoped to achieve a cure rate of at least 90% were able to observe a better result with a cure rate of 96% ! The researchers are also pleased to have been able to work together on this complex clinical trial requiring a phase 1 trial to verify tolerance, then a phase 2 trial to test effectiveness. Enough to give hope to the scientific community that one day it will be possible to eliminate all existing gestational trophoblastic tumors in young women of childbearing age.
The publication of these promising results is planned for early 2025. The authors then intend to exploit them within the framework of a application for marketing authorization and reimbursement for avelumab treatment in this indication. If scientists aim to be able to offer access to this new treatment to patients in routine care, they are aware that this may still take time. To be continued!
Déborah L., Doctor in Pharmacy
Sources
– Gestational trophoblastic tumors: a new treatment would allow 96% cure. www.lequotidiendumedecin.fr. Accessed September 25, 2024.
– Avelumab sheet. www.vidal.fr. Accessed September 25, 2024.
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