SAN FRANCISCO – Compressing damaged lung tissue with endobronchial coils improves exercise tolerance in patients with severe emphysema, albeit with the tradeoff of more adverse events, concludes the phase 3 RENEW trial.
After a year of treatment, the 6-minute walk distance had improved in patients given coils, whereas it had worsened in patients managed with usual care, with a difference of nearly 15 meters between groups, investigators reported at an international conference of the American Thoracic Society and simultaneously published (JAMA. doi:10.1001/jama.2016.6261. Published online May 15, 2016).
However, the median gain with coils fell short of the study’s predefined minimal clinically important difference of 25 meters. Additionally, major complications, mainly lower respiratory tract infections, were more common with the coils, although they resolved with time.
Dr. Frank C. Sciurba
“Participants in the RENEW trial had advanced disease. Seventy-seven percent had homogeneous emphysema. This is a group that has very few therapeutic options,” commented lead investigator Dr. Frank C. Sciurba, director of both the Emphysema Research Center and the Pulmonary Function Exercise Physiology Laboratory at the University of Pittsburgh.
“The response rates of endobronchial coils to improve quality of life and exercise tolerance in these severely symptomatic patients balanced against peri-procedural adverse events in this population provides an evidence-based choice for symptomatic patients and treating physicians when there are few other options in these patients,” he said.
RENEW (Lung Volume Reduction Coil Treatment in Patients With Emphysema) was conducted among 315 patients from the United States, Canada, the United Kingdom, Germany, the Netherlands, and France who had emphysema with severe air trapping.
“This was a very inclusive study. In contrast to the surgical and valvular studies, we randomized nearly half of those screened because we allowed patients with homogeneous disease and of course didn’t select based on fissure integrity, which is a selection criterion for other studies,” Dr. Sciurba commented.
The patients received either guideline-based usual care alone (including pulmonary rehabilitation and bronchodilators) or with the addition of bilateral, bronchoscopically placed coils (RePneu Lung Volume Reduction Coil System, currently investigational in the United States).
At 12 months, the median 6-minute walk distance had improved by 10.3 meters with coil treatment but worsened by 7.6 meters with usual care (P = .02). The proportion of patients attaining an improvement of at least 25 meters was higher in the coil group (40.0% vs. 26.9%; P = .01).
In exploratory analyses, patients having more nonpulmonary comorbidities at baseline derived lesser benefit in walk distance from coil treatment, Dr. Sciurba noted.
The coils also netted greater improvement in the median change in forced exploratory volume in 1 second (FEV1) (difference between groups, 7.0%; P < .001) and in scores on the St. George’s Respiratory Questionnaire (difference between groups, −8.9 points).
At the same time, patients in the coil group had higher rates of major complications such as pneumonia requiring hospitalization and other potentially life-threatening or fatal events (34.8% vs. 19.1%, P = .002) and of other serious adverse events such as pneumonia (20% vs. 4.5%) and pneumothorax (9.7% vs. 0.6%).
“All of these adverse events returned to baseline at 9 to 12 months,” Dr. Sciurba reported. Additionally, there was no significant difference between groups in mortality rate.
Of note, 35% of the 40 cases of coil-associated opacities initially thought to be pneumonia were in fact determined to likely be a noninfectious inflammatory reaction to the coils. “These adjudicated noninfectious coil-associated opacities were associated with a better response,” he noted.
Finally, in stratified analyses, patients with greater air trapping at baseline had better-than-average improvements in outcomes with the coils, regardless of whether they had homogeneous or heterogeneous disease. Among patients with lesser air trapping, those with homogeneous disease derived much less benefit than the average from coils, while the group with heterogeneous disease was too small to draw any conclusions.
Dr. Sciurba disclosed that he receives institutional support from PneumRx and Pulmonx. The study was sponsored by PneumRx.