Late-breaking abstract: Riociguat for the treatment of pulmonary arterial hypertension (PAH): 2-year results from the PATENT-2 long-term extension

In the 12-wk PATENT-1 study, riociguat significantly improved 6MWD and other secondary endpoints in PAH pts. Improvements persisted for a further 1 yr in PATENT-2. We present 2-yr data from PATENT-2, the final analysis before most pts switch to the commercial drug. PAH pts who were treatment-naive or pretreated with ERAs or prostanoids entered PATENT-2 after completing PATENT-1 without ongoing riociguat-related SAEs. All pts received riociguat adjusted up to 2.5 mg tid. Primary endpoints were safety and tolerability; secondary endpoints included 6MWD and WHO FC. Of 405 pts completing PATENT-1, 396 (98%) entered PATENT-2. At this cut-off (March 2014), 275 (69%) pts were ongoing, 307 (78%) had received ≥2 yrs of treatment and 13 (3%) had switched to the commercial drug. Riociguat was well tolerated; 10% of pts withdrew due to AEs. The most common drug-related AEs were dizziness (10%), headache (8%) and dyspepsia (9%). There were 13 (3%) drug-related SAEs of syncope and 4 (1%) drug-related SAEs of pulmonary bleeding. Mean±SD 6MWD increased from PATENT-1 baseline by +37±52 m in riociguat 2.5 mg–maximum pts vs +12±58 m in placebo pts at the end of PATENT-1 and by +47±85 m at 2 yrs (n=296). At the end of PATENT-1, WHO FC improved/stabilized/worsened in 21/78/2% of riociguat 2.5 mg–maximum pts vs 16/75/9% of placebo pts; proportions were 33/58/9% at 2 yrs (n=306). At 2 yrs, survival was 93% and 17% of former therapy-naive pts were receiving additional PAH therapy. Analyses of correlation between efficacy endpoints and long-term outcomes will be presented. Riociguat has a good long-term safety profile and shows sustained clinical effect for up to 2 yrs in PAH pts.