Riociguat in pulmonary arterial hypertension: Application of the 4-strata COMPERA 2.0 risk assessment tool in the PATENT studies.

BACKGROUND

Risk stratification is an essential part of evaluating disease severity in patients with pulmonary arterial hypertension (PAH). This study applied the 4-strata COMPERA 2.0 risk model to the Phase 3 PATENT-1/2 studies of riociguat.

METHODS

This was a post hoc analysis of PATENT-1 and PATENT-2. Log-rank tests of Kaplan-Meier curves were performed to compare the risk strata at PATENT-1 baseline and Week 12 regarding time to clinical worsening and survival at 2 years in the PATENT-2 population.

RESULTS

Data on COMPERA 2.0 status at baseline were available for 214 patients with riociguat and 100 with placebo; overall, 120 patients were identified as intermediate-low risk and 96 as intermediate-high risk. At PATENT-1 Week 12, improvements in COMPERA 2.0 risk strata and median 6-min walk distance were seen with riociguat vs placebo in patients assessed as intermediate-low risk and intermediate-high risk at baseline by COMPERA 2.0. More patients improved their COMPERA 2.0 risk status with riociguat vs placebo in the intermediate-low (38 % vs 22 %) and intermediate-high risk groups (42 % vs 31 %). COMPERA 2.0 assessed at PATENT-1 baseline and Week 12 discriminated between risk strata for survival and clinical worsening in PATENT-2 at 2 years (p ≤ .001 for all analyses).

CONCLUSIONS

In conclusion, this analysis supports the risk-reduction benefits of riociguat in patients with PAH at intermediate-low risk and intermediate-high risk, and externally validated the utility of COMPERA 2.0 in the long-term risk assessment of patients from a clinical trial population.