The safety and persistence of intravenous iloprost in systemic sclerosis

Vasculopathy is a crucial feature of systemic sclerosis (SSc). It occurs in almost every patient with SSc, with Raynaud's phenomenon (RP) and digital ulcers (DU) having a great impact on the quality of patients' lives. Intravenous (IV) iloprost, a synthetic analogue of prostacyclin, is broadly used to treat RP and DU secondary to SSc. Currently, there is no standard protocol defined for the iloprost treatment of SSc-associated RP and DU, and, consequently, the management of this treatment is largely based on each centre's experience.

The objective of this study is to evaluate the safety profile of a particular scheme of IV iloprost used in our centre as the standard treatment of SSc-related vascular complications.

We retrospectively evaluated the clinical records of SSc patients, classified according to the 2013 European Alliance of Associations for Rheumatology (EULAR) criteria (31) with SSc-related DU and/or severe RP not responsive to CCB, receiving or who have received IV iloprost infusions from January 1st 2011 to March 31st 2021 Results: Within this time frame, 60 patients (n=44 for DU; n=16 for severe RP) were treated with a monthly 10-hour IV iloprost perfusion with a dosing regimen adapted to individual tolerance. Forty-nine of these 60 patients (81.7%) were on iloprost for more than one year. Within 12 months of therapy, 40 patients have healed the DUs (90.9%), with only 4 patients maintaining active DUs. A significant clinical improvement in RP at 12 months was observed in 87.5% (n=14/16) of SSc patients with severe RP. Eleven AE implying treatment dose/frequency adjustments or suspension were recorded (18.3% of patients): severe headache (n=5), hypotension (n=3), tachycardia (n=1), flushing (n=1) and generalised erythroderma (n=1). In all patients, the perfusion rate was reduced in the following treatment sessions with good tolerance, with the exception of the patient with the generalised erythroderma reaction, who suspended the perfusion and was later switched to bosentan. After a mean follow-up time of 6.9 (+/-) 4.0 years of treatment (range 0.06-22), 24 patients (40%) stopped the therapy, 14 (58.3%) of whom due to clinical improvement. The overall 5-, and 10-year survival rates of IV iloprost were 68.2% and 55.6%, respectively.

SSc patients who received this flexible IV iloprost regimen achieved clinical improvement, reflected in the high persistence rate of the drug, with a good tolerability profile. In addition, most side effects were mild and easily managed.