Response to drug therapy may not be uniform across a heterogeneous population. Responder analyses, which dichotomize the response at a specific level of interest, can be helpful in gauging the utility of an intervention. The objective of this study was to evaluate the response to infliximab therapy in a randomized trial of 138 patients with chronic pulmonary sarcoidosis using clinically meaningful dichotomous endpoints for pulmonary function, symptoms, and physical function.
Primary and major secondary endpoint data at 24 weeks from a placebo-controlled study of infliximab were explored. The analyses are presented as the number (%) of responders using varying definitions for improvements in forced vital capacity (FVC), St. George’s Respiratory Questionnaire (SGRQ) score, Borg’s CR10 dyspnea score post 6 minute walk (6MW), and 6 MW distance (6MWD).
At week 24, there was a trend for more subjects having improved pulmonary function as measured by FVC with infliximab treatment using all definitions.All three groups responded similarly in SGRQ. For the combined infliximab group, there were more responders using Borg’s CR score post 6MW (p=0.028) or 6MWD (p=0.011). For 6MWD, the difference would translate into a number needed to treat (NNT) of 6.
Responder analyses can be helpful in identifying clinically meaningful treatment effects, and can be useful to help gauge the NNT to achieve the level of benefit of interest.
Infliximab appears to be associated with larger improvements in some endpoints in a subset of subjects, despite aggressive medical therapy. A larger trial of infliximab in such a population appears warranted.
M Drent, Grant monies (from industry related sources) Research grants; Consultant fee, speaker bureau, advisory committee, etc.; Employee.