Background and aims: To evaluate the safety, pharmacokinetics and clinical efficacy of the intercellular adhesion molecule-1 antisense phosphorothioate oligonucleotide alicaforsen (ISIS 2302) at 250-350 mg in Crohn's disease.
Methods: : Patients (> 50 kg) with active Crohn's disease (Crohn's disease activity index > or = 220) were assigned by gender, randomly, to two alicaforsen treatment groups: 300 or 350 mg, infused intravenously three times a week for 4 weeks. All patients weighing 36-50 kg received 250 mg of alicaforsen. Background aminosalicylates, antibiotics, immunosuppressives and corticosteroids were permitted, but tumour necrosis factor-alphainhibitors were prohibited. The primary end-point was clinical remission (Crohn's disease activity index < or = 150).
Results: Twenty-two patients were enrolled with a mean baseline Crohn's disease activity index of 304. Steroids were used by 27%, 5-aminosalicylic acid by 68% and immunosuppressives by 27%; 23% had previously received infliximab. Five subjects withdrew after one to three infusions for infusion-related symptoms. Nine patients (41%) experienced clinical remission. Fifty-three per cent of the evaluable subjects receiving more than three infusions experienced remission (18% at week 8; 29% at week 12). The overall response, using a minimum decrease of 70 in the Crohn's disease activity index, was 41-47% for the evaluable group, at weeks 8 and 12. The median duration of remission was 14 weeks. Plasma pharmacokinetic results showed overlapping levels (Cmax, AUC) for the three doses. The infusion-related reaction profile consisted of fever, chills, headache, nausea, emesis or arthralgias, typically occurring 2-4 h after completion of the first infusion. Reactions were less frequent in patients receiving background corticosteroids. The 2-4-h transient post-infusion partial thromboplastin time prolongation values, a class effect of phosphorothioate oligonucleotides, were 18, 21 and 23 s for 250, 300 and 350 mg, respectively.
Conclusions: Alicaforsen (ISIS 2302), at fixed doses of 300 and 350 mg, achieved the desired drug exposure and may be an effective therapy for Crohn's disease. Infusion-related reactions were observed less frequently in patients on corticosteroids, and with decreasing frequency with continued treatment.