Kalydeco Shows Long-term Efficacy in CF Patients in Real-world Setting

Kalydeco (ivacaftor) preserved lung function, improved the nutritional status, and reduced hospital visits and chronic bacterial infections in people with cystic fibrosis (CF) when administered for up to five years in a clinical setting, a long-term, real-world, observational study showed.

The study, “Disease progression in patients with cystic fibrosis treated with ivacaftor: Data from national US and UK registries,” was published in the Journal of Cystic Fibrosis.

CF is caused by mutations in the CFTR gene that holds the instructions to produce a transport protein called cystic fibrosis transmembrane conductance regulator (CFTR). The faulty function of this protein causes the accumulation of mucus in several organs.

Kalydeco is a treatment developed by Vertex Pharmaceuticals that targets the underlying cause of CF in people with specific mutations. The therapy was approved by the U.S. Food and Drug Administration (FDA) in 2012 after slowing disease progression in several clinical trials. After that, it was also approved in Europe, New Zealand, and Canada.

From the moment of approval, researchers from the U.S. and U.K. started to gather data regarding the effectiveness of Kalydeco in the clinical setting, by comparing the outcomes of patients who received the therapy to those of patients who did not.

Now, researchers analyzed data from these two cohorts.

They evaluated the differences in lung function, measured by forced expiratory volume (FEV); nutritional status, measured as body mass index (BMI); number of acute pulmonary episodes (disease exacerbations), measured as the need for intravenous antibiotics; number of hospitalizations; incidence of CF-related diabetes, and presence of chronic infections caused by Pseudomonas aeruginosa bacteria.

The U.S. cohort consisted of 635 patients who received Kalydeco for five years, and 1,874 patients who did not receive the treatment. The U.K. cohort included 247 patients who received Kalydeco for four years, and 1,230 patients who did not. None of the patients received a lung transplant during the study.

The data were obtained from the U.S. Cystic Fibrosis Foundation Patient Registry (CFFPR) and the U.K. Cystic Fibrosis Registry (CFR).

Results showed that Kalydeco preserved lung function. In the U.S. cohort, patients taking Kalydeco had a decrease in FEV of 0.7%, whereas the reduction for those not taking the treatment was 8.3%. In the U.K. cohort, the therapy improved pulmonary function (increase of 4.9% in FEV values), compared to FEV decrease of 4.3% in patients not receiving Kalydeco.

Kalydeco was also found to induce a significant increase in BMI in both cohorts, suggesting an improvement in patients’ nutritional status.

Patients from both cohorts treated with Kalydeco had fewer exacerbations and hospitalizations during each year of the study, and a lower incidence of CF-related diabetes and chronic bacterial lung infections than patients not taking the treatment.

The Kalydeco group also tended to survive longer and need fewer lung transplants, although the difference was not statistically significant.

“Our findings from much larger patient cohorts in the U.S. and the U.K. followed for up to five  years show sustained favorable effects of [Kalydeco] therapy on disease progression. The results are consistent with the findings observed in the earlier studies,” the researchers said.

According to the team, “this observational study represents the largest longitudinal analysis of patients treated with [Kalydeco] in a real-world setting. The findings support disease modification by CFTR modulation with [Kalydeco].”