gene therapy

The journal Nature Medicine has published the results of the phase III STEER clinical trial for the treatment of spinal muscular atrophy in children aged between two and 18 years. A single dose of gene therapy administered directly into the cerebrospinal fluid showed an improvement in motor function in the children who received it in the clinical trial (75 compared to 51 with placebo). The drug in question is onasemnogene abeparvovec. On 24 November, the US Food and Drug Administration approved this treatment under the trade name Itvisma, from Novartis, based on data from this trial, making it the first treatment available for children over two years of age.

Severe combined immunodeficiency due to ADA enzyme deficiency is a rare disease that, without treatment, usually causes death within the first two years of life. These "bubble children" are currently treated with a bone marrow transplant or with injections that aim to restore, to the extent possible, the function of this enzyme. Now, an international team presents the results of a gene therapy administered to 62 children with the disease between 2012 and 2019. The therapy was effective in 95% of cases and did not cause serious complications, according to the authors, whose work is published in the journal NEJM. 

A team from the Netherlands has successfully edited pathogenic mutations in mitochondrial DNA in human cells, changes in DNA that cause disease, according to research published in PLoS Biology. The authors used a genetic tool known as a base editor. Until now, techniques derived from CRISPR have made it possible to correct mutations in nuclear DNA, and new techniques are being developed that allow mitochondrial DNA to be edited.

The regulatory agencies for medicines in the United States and Europe have issued statements informing about a possible risk of developing certain types of tumors following CAR-T cell immunotherapy treatment. What do we know so far? What is the real risk? Does the benefit-risk balance still hold? Has anything changed after these alerts? We answer these questions with expert opinions and the data currently available. 

Hurler syndrome is a rare and very serious disease caused by an enzyme deficiency, which results in a wide variety of signs and symptoms. Treatment with bone marrow transplantation helps to alleviate some of them, but has little effect on skeletal disorders. Now, a phase I/II trial has tested an autologous transplant of blood stem cells corrected by gene therapy in eight patients. The results, published in the journal Science Translational Medicine, suggest that the treatment is more effective and could also improve these types of disorders. 

Epigenetic editing is a technique that aims to alter gene expression without the need to modify the DNA sequence, as gene editing techniques do. In this way, Italian researchers have succeeded in silencing the PCSK9 gene in mice, thereby reducing cholesterol levels by half for at least a year. According to the authors, and assuming further evaluation is needed, their platform "could lay the foundations for the development of this type of therapy". The results are published in the journal Nature.