Efficacy and safety of oral porcine relaxin (pRLX) in adjunct to physical exercise in the treatment of peripheral arterial disease (PAD).

PAD medical therapy has a number of limitations. RLX showed promises in experimental model mainly through NO release. Our study is the first to evaluate the efficacy and safety of RLX in PAD.Eligible PAD La fontaine IIa-IIb patients were randomized in 2 groups. Group A was treated with physical therapy plus oral pRLX, 20 ug b.i.d for 12 weeks, group B received physical therapy alone. Pain Free Walking Distance (PFWD) and Maximum Walking Distance (MWD) at 3 and 12 wks and at follow up 3 months after treatment interruption were performed.The percentage increases of PFWD in group B were 23 +/- 9, 65 +/- 17, and 35 +/- 4 respectively at 3 and at 12 weeks, and 3 months after termination. In Group A showed significantly higher percentage increases: 74 +/- 16 p < 0.01, 168 +/- 28 p < 0.001, and 122 +/- 15 p < 0.001 at the corresponding time points. The percentage increases of MWD in the B group were 29 +/- 7, 55 +/- 10 and 54 +/- 8 at the above time points, while in the A group were 55 +/- 10 p < 0.001, and 99 +/- 12 p < 0.001. The RLX patients referred a better physical and mental status. No adverse events during or after the treatment were recorded.RLX resulted very effective in PAD. Our results may suggest that the observed functional benefits should come not only from hemodynamic improvement but also from positive vascular remodeling.