Complete clearance occurred at 12 months in 31% of patients who received field treatment with ingenol mebutate gel after cryotherapy for actinic keratoses, compared with 19% of placebo patients in a phase III trial.
The findings were published in the June issue of the Journal of Drugs in Dermatology.
Recurrence rates for AKs treated with cryotherapy alone are high, possibly because the treatment is lesion-directed and fails to address field cancerization, wrote Dr. Brian Berman of the University of Miami.
The FIELD study 1, a phase III, multicenter, randomized trial, showed that ingenol mebutate gel was safe and effective as a follow-up to cryosurgery for AKs. Short-term efficacy data (11 weeks) have been previously reported.
In this study, the patients were followed for 12 months (J. Drugs Dermatol. 2014;13:741-7).
Dr. Brian Berman
"In phase III clinical trials, 2 or 3 days of field-directed therapy with ingenol mebutate demonstrated high and sustained clearance of AKs on the head and body, and was well tolerated," noted Dr. Berman and his coauthors.
The percentage reduction in the number of AKs was significantly higher at 12 months in the treatment group compared with the placebo group (68% vs. 54%), and significantly fewer patients in the treatment group developed new lesions in the treatment area compared with the placebo group (39% vs. 52%). In addition, the probability of sustained clearance of AKs at 12 months was 55% in the treatment group vs. 40% in the placebo group.
The study included 329 adults aged 18 years and older with 4-8 clinically typical, visible, and discrete AKs within a 25-cm2 treatment area on the face or scalp. The patients underwent cryosurgery, and 3 weeks later underwent field therapy with 0.015% ingenol mebutate gel or vehicle gel once a day for 3 consecutive days. Patients with suspected basal cell carcinoma or squamous cell carcinoma were excluded.
The findings were limited by the possible unblinding of treatment because of localized skin reactions, the researchers noted. However, few drug-related adverse events and no drug-related serious adverse events were reported, they said.
Dr. Berman has served as a consultant, received honoraria, and served on the speakers bureau for Leo Pharma, which funded the study.