CHICAGO – Taking a personalized approach to treating dyspnea will result in better outcomes, and will make choosing between surgical and the increasing number of nonsurgical techniques an easier process, according to Dr. Frank Sciurba, a presenter at the annual meeting of the American College of Chest Physicians.
In a talk that reviewed current and trial surgical and bronchoscopic treatments of dyspnea in chronic obstructive pulmonary disease, Dr. Sciurba said, "Just treating diseases that are now naively classified as COPD or [interstitial lung disease] is not enough. We can instead look at variations within those diseases that may or may not be responsive to different therapies."
For example, because the Impact of Heterogeneity on Outcome Following Endobronchial Valves (VENT) trial data showed that fissure integrity (collateral tracts) significantly influenced target and adjacent lobe volume changes, Dr. Sciurba said that medical device manufacturers have begun to develop technologies that are more specific to the patient.
Straight nitinol coils (PneumRx), which are placed bronchoscopically, are implanted in stages, and according to collateral tracts. "The concept is to target the most affected areas of the lung, allowing regional expansion of the least affected lung. It’s not dependent on just lobar re-expansion," said Dr. Sciurba, director of the emphysema research center at the University of Pittsburgh Medical Center.
Pilot trial data for this technique published in CHEST earlier this year showed that patients (n = 56) had a 17.5% improvement in forced expiratory volume in 1 second (FEV1) and a greater than 10% drop in residual volume, and clinical meaningful improvements in 6-minute walk distances at more than a 28% improvement from baseline: 73% had a greater than 25 meter improvement at 6 months post treatment.
The hydro-gel foam, AeriSeal (Aeris) is another bronchoscopic technique currently undergoing a small (n = 20) pilot trial. After fibrinogen was eliminated from the sealant, this polymeric lung volume reduction technology was cleared by the Food and Drug Administration for testing in humans.
The sealant is administered into specific subsegments of the lungs, where the foam adheres to surrounding tissues; air and water in the foam are reabsorbed when collapse occurs, with durable absorption in atelectasis.
The results will soon be published, although Dr. Sciurba said that at this point, "the mechanical benefits seem to exceed the symptomatic benefits," but that a trial in a larger population would produce more definitive results.
Other factors to consider include "understanding the pulmonary physiologic interaction in lung volume reduction, and how that translates downstream, and the importance of linking the mechanical intervention with pulmonary rehab."
Expanding the ‘tool chest’
In determining whether bronchoscopic solutions can achieve the same benefits of surgical ones, while also minimizing adverse effects, Dr. Sciurba said, the FDA is beginning to take a more personalized view when approving trials, which he hopes will increase the "tool chest" available to physicians.
Clinical trials going forward may need to consider selection criteria such as interlobar collaterals, regional emphysema heterogeneity, and the degree of hyperinflation, as well as the most relevant outcomes when determining adverse events, Dr. Sciurba said.
Whether therapies are reversible also will be relevant, and will have an impact on future criteria for lung volume reduction surgery and transplant candidacy.
"If we actually look in a little more detail and start to classify these patients both on physiologic and clinical patterns, and as we evolve, on genetic patterns and molecular patterns, we will isolate groups of patients who are home run responders from those in whom certain therapies may not be cost effective."
Dr. Sciurba disclosed that he has received support from AstraZeneca, GlaxoSmithKline, Pfizer, and other companies, as well as grant monies from the National Institutes of Health and the University of Pittsburgh.