Current clinical trials evaluating combination therapy for pulmonary artery hypertension (PAH) may be longer than what is needed to demonstrate treatment benefit, results of a recent meta-analysis suggest.
, according to results of the study published in the May issue of the journal Chest®.
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The meta-analysis by Dr. Lajoie and her colleagues included 3,801 patients enrolled in one of 15 previously published randomized clinical trials. Of those trials, four were long-term, event driven studies, with a mean duration of 87 weeks, while the remainder were shorter studies with a mean duration of 15 weeks.
For the long-term, event-driven trials, the mean number needed to treat (NNT) was 17.4 at week 16, gradually decreasing to 8.8 at 52 weeks of follow-up, remaining stable after that, according to investigators.
Consistent with that finding, the mean relative risk of clinical worsening was 0.38 at 16 weeks, and similarly, 0.41 at 26 weeks, investigators reported. After that, the relative risk progressively increased to 0.54 at 52 weeks and 0.68 at 104 weeks.
Looking at all trials combined, Dr. Lajoie and her colleagues observed that longer trial duration had a positive correlation with relative risk of clinical worsening (P = .0002).