Published on 23.04.2017
Gene therapy: hope for genetic diseases
Gene therapy is the dream for patients with genetic diseases as it replaces the “sick” gene with a healthy gene. In reality it is a lot more complex that it seems. As the first clinical trials in children with X-linked severe combined immunodeficiency showed in 1999, that she conducted with Prof. Alain Fischer and Prof. Salima Hacein-Bey-Abina (Inserm Unit 768 Normal and pathological development of the immune system”, Biological Therapy Department and Pediatric Hematology and Immunology Unit, Necker-Enfants Malades hospital AP-HP, Paris Descartes University, Paris). Even though they showed the efficacy of this innovative treatment for the first time, they also uncovered faults that have to be resolved. Since, the treatment has continued to improve and it is now used for other diseases.
“Gene therapy can be done in vivo directly into the patient’s body. This approach is favored in central nervous system, neuromuscular or metabolism diseases, describes the professor. As a specialist of blood diseases, the approaches that I have developed with my team take place ex-vivo.” At first, bone marrow stem cells, the cells capable of generating all cell lines in the blood, are taken. Before reinjecting them into the patient, a functional gene is introduced into the cells to make up for the defective gene. “With this approach, we have recently been able to cure children with two forms of genetic anemia: sickle-cell anemia and beta-thalassemia”, rejoices Marina Cavazzana. Patients treated with gene therapy now produce enough hemoglobin and no longer need transfusions.
Discovering other avenues
“In theory, gene therapy could be offered to all patients with genetic disease, she continues, although I am aware that this will not be possible. Research must therefore continue to develop other therapeutic approaches.” And the one for which the conviction is greater than the restrictions against gene therapy already has different leading avenues to reduce transplant rejections from partially compatible donors among other things. As in this case, the chances of success do not exceed 50%, and can reduce to 30% sometimes, against 90% with a compatible family donor.
In this fight, she emphasizes the importance of being at Imagine: it is an accelerator for my work, she explains. My team has the most advanced technologies but also a multidisciplinary network of researchers and doctors around them. She hopes that gene therapy trials soon emerge in other diseases such as myopathies.
To treat the patient more and more, the hematology professor launches a new challenge: to encourage future generations of doctors in all specialties to be creative and go beyond what they are taught to develop the innovative therapies of tomorrow.
Being at Imagine: it is an accelerator for my work
The fight of a committed woman
Indeed, there is still a lot to explore to reduce genetic diseases and it is by breaking down the walls that new solutions will emerge tomorrow, and this does not just concern treatments: according to her, reducing the isolation of teenagers being cared for also has to be done, by using means of communication that are more appropriate for these generations.
2012 winner of the Irène Joliot-Curie prize awarded by the French Ministry of Research, she lives up to the title of scientific woman of the year and does not stop deploring the under-representation of women in science and medicine. In her laboratory, some simple rules ensure that it is a fair place for everyone: no meeting after 5pm, arranging working times for women with young children, protection regarding comments or attitudes of other colleagues that are uncalled for, support until a position is secured. That also is about breaking down the wall of silence towards the abuse of power, she recalls.
Marina Cavazzana is fighting and applying to herself the motto that she feels so strongly about: do not lose heart and never give up.
Marina Cavazzana is a hematology professor at Paris Descartes University, head of the Biological Therapy Department and the Biotherapy Clinical Investigation Center at the Necker-Enfants Malades hospital, AP-HP and co-director of the Inserm Human Lymphohematopoiesis Laboratory at the Imagine Institute of genetic diseases, Paris, France.