Current treatment paradigms for PAH suggest adopting goals of therapy with relatively objective parameters such as 6 minute walk distance to determine when to add a second oral agent (1). This often entails observing deterioration in the patient on a single agent before instituting the second one. This strategy could be problematic, as patients may never recover the function lost due to progressive PAH (2). In addition, given the malignant nature of the clinical course of PAH in many cases and the nature of the underlying proliferative vasculopathy, some have argued that altering this paradigm to resemble that used in cancer chemotherapy may be more appropriate (3). That is, "induction" therapy at diagnosis with multiple agents followed by a maintenance phase of treatment might offer significant benefits to the patient.
This open-label pilot study is the first to investigate the potential efficacy and safety of a first-line combination strategy in consecutive patients with PAH in contrast to the "add-on" strategy for combination therapy. It will serve as the basis on which to consider larger, multicenter investigations of this strategy.
1. Hoeper M, et al. Eur Respir J. 2005 Nov;26(5):858-63.
2. Halpern SD, et al. Proc Am Thorac Soc. 2008 Jul 15;5(5):631-5.
3. Provencher S, et al. Chest. 2005 Dec;128(6 Suppl):622S-628S.
