Clinical Outcome of Topical Interferon Alpha-2b Cream in Phase II Trial for LSIL/CIN 1 Patients

Objectives: Interferon alpha-2b possesses variable activity against human papillomavirus (HPV) associated cervical intraepithelial neoplasia (CIN). No topical therapy is currently available for treatment of early stage CIN. We evaluated a new patented drug delivery technology in order to achieve topical efficacy. Methods: Two separate studies were conducted in parallel. IFN002 (treatment group) was an open label study. Twenty patients with Pap IIW, III and IIID (CIN1) were treated with intravaginal application of Interferon alpha-2b cream (5 g, 2 MIU/g) three times a week (alternate days) for 6 weeks with 6 weeks of follow up to determine its effect on cytologic and colposcopic assessment. HPV001 (control group) was a 12 week observational study. Both studies had similar inclusion/exclusion criteria and patient population. Results: In IFN002, 8 of 20 patients (40%) in the ITT population showed resolution of abnormal Pap smear during the 12 weeks following start of treatment (responders). In HPV001, 7 of 21 patients (33.3%) were regressors (p = 0.45, one-sided FET). In the PP population, 7 of 12 (58.3%) patients in IFN002 were regressors compared to 7 regressors of 19 patients (36.8%) in HPV001 patients (p = 0.21, one-sided FET). Among patients with Pap IIID, 8 of 14 patients in IFN002 showed resolution of abnormal Pap smear, while 4 of 14 patients resolved in HPV001 (one-sided FET, p = 0.13). Conclusions: Interferon alpha-2b cream (5 g, 2 MIU/g) may be an effective treatment for CIN 1 patients, and future investigation is warranted.