Patients treated with Ofev (nintedanib) or Esbriet (pirfenidone) for pulmonary fibrosis in a real-world setting have similar rates of side effects as those reported in clinical trials testing the drugs, despite being older and often having more severe lung disease and a host of other medical conditions.

Published in the journal Respirology, the study was the first to attempt to see how tolerability and side effect rates differed in clinical practice compared to the large Phase 3 studies assessing Ofev and Esbriet.

The study was conducted by researchers at the Lewis Katz School of Medicine at Temple University in Philadelphia, and the results were reported in the article “Pirfenidone and nintedanib for pulmonary fibrosis in clinical practice: Tolerability and adverse drug reactions.”

The team reviewed medical records of 186 patients — 129 treated with Esbriet and 57 with Ofev. Researchers followed Esbriet patients for an average of 52 weeks, and Ofev patients for 41 weeks.

Patients included in the study had significant breathing difficulties, with 63 percent requiring home oxygen therapy. They had an average airway gas diffusion ability of 36 percent of what is predicted for people their age. Along with lower forced vital capacity (FVC; a measure of lung function), this indicated that these patients were worse off than those included in the Phase 3 trials.

The clinical trials had also excluded patients with other health issues from participating. In the current study, about half the patients had gastroesophageal reflux disease, about one in four had diabetes or coronary artery disease, 15% to 19% had pulmonary hypertension, about 7% had heart failure, and about 20% had lung fibrosis with emphysema.

The majority — 81.7% — of patients had idiopathic pulmonary fibrosis, but other forms of lung fibrosis were also represented.

These factors made the patient group very different from those studied in the clinical trials, and researchers figured that adverse drug reactions, particularly those causing a patient to stop the treatment, would be more common.

But they were surprised to find that this was not the case. Side effects occurred at similar rates as those reported in the trials — CAPACITY (NCT00287729 and NCT00287716) and ASCEND (NCT01366209) for Esbriet, and INPULSIS 1 and 2 (NCT01335464 and NCT01335477) for Ofev.

Also, the number of patients who stopped the treatment after an adverse event was similar in the current study to that noted in clinical trials — 20.9 percent of Esbriet-treated patients and 26.3 percent of those taking Ofev stopped their treatment because of side effects.

Researchers said that a history of congestive heart failure and an age of 70 or more were the only factors linked to treatment discontinuation.

However, although the study has indicated that safety in this real-world patient population does not differ from what clinical trials had reported, researchers currently do not know if the drugs benefit these patients — who have more severe health issues — equally well as that seen in the controlled studies.

Following patients in clinical practice over time could answer this question, researchers said.