Objective: To determine the safety and efficacy of prolonged treatment with 15-deoxyspergualin (DSG, gusperimus) in patients with relapsing WG.
Methods: Patients with relapsing WG treated with DSG were studied. Other immunosuppressants except corticosteroids were withdrawn and DSG, 0.5 mg/kg/day, self-administered subcutaneously for up to 21 days, in 28-day cycles. The cycle was terminated early for white blood cell count <4 x 10(9)/l. The prednisolone dose was adjusted according to the clinical state. End points were disease remission, relapse, Birmingham Vasculitis Activity Score (BVAS), prednisolone dose and safety.
Results: Eleven patients, five (45%) of whom were female, received a total of 15 treatment periods with DSG. The median (range) duration of each treatment period was 6.8 (3.3-15.9) months. Ten (90.9%) patients responded in 13/15 courses after a median of 1.7 (0.7-2.7) months and six (54.5%) achieved remission after 7.7 (1.9-13.5) months. Two (18.2%) patients relapsed while continuing to receive DSG. Remission was maintained in other patients while DSG was continued. However, 7/8 relapsed after DSG withdrawal. The median BVAS fell from 10 (3-22) at baseline to 3 (0-16) at the end of each treatment period (P = 0.002). Median prednisolone doses were reduced from 20 (5-30) mg/day at baseline to 10 (5-25) mg/day at the end of each treatment period (P = 0.052). Three severe adverse events occurred in two patients.
Conclusions: Extended treatment with DSG was effective in the majority of patients with relapsing WG and permitted prednisolone reduction. There was no unexpected toxicity associated with prolonged DSG administration.