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Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: Selexipag is a first-in-class orally available selective non-prostanoid IP receptor agonist. This review was based on a PubMed search and focuses on the potential role of selexipag in the treatment of pulmonary arterial hypertension (PAH). Selexipag is rapidly hydrolyzed to an active metabolite, ACT-333679. Both selexipag and its metabolite are highly selective for the IP receptor compared with other prostanoid receptors. This selectivity for the IP receptor offers the potential for improved tolerability with selexipag, as side effects (e.g., nausea and vomiting) that might result from activation of the other prostanoid receptors may be minimized. In addition, the selexipag metabolite has a half-life of 7.9 h, thus permitting oral dosing twice daily. Selexipag showed effects on pharmacodynamic end points obtained with right heart catheterization in a Phase II trial in patients with PAH, and is being evaluated in the ongoing Phase III trial (GRIPHON trial, Clinicaltrials.gov NCT01106014). The signal of a beneficial effect of selexipag on disease progression may become more robust for long term under prolonged exposure. Pending the GRIPHON trial results, selexipag could provide a convenient first-line prostacyclin treatment option for patients with PAH.
Question: Selexipag is used for which disease?
Output:
pulmonary arterial hypertension