This review looked at ten small studies involving 424 people with cystic fibrosis. These patients have two copies of the F508del gene variant. The doctors tested if taking just one CFTR modulator drug helped them breathe better or feel better. The drugs tested included lumacaftor, cavosonstat, and others.
The results showed no deaths in the studies. However, the review could not prove that these single drugs improved lung function or quality of life. Some patients did not feel any difference compared to taking a placebo or another single drug.
Safety checks found no major differences in side effects between the drug groups. However, very few people had side effects, so it is hard to say if the drugs are safe or not. The longest study only lasted 29 days, which is too short to know if the drugs work long term.
Because the evidence is very weak, doctors should not use single drug therapy for these patients. More research is needed to find the best treatment plan for people with two F508del gene variants.