Tirbanibulin is superior to vehicle at two months for the treatment of actinic keratosis, but almost half of patients who had a complete response experienced recurrence of lesions at one year, according to a study in New England Journal of Medicine.
Dr Andrew Blauvelt, from the Oregon Medical Research Centre in Portland, and colleagues randomly assigned adults with actinic keratosis on the face or scalp to receive either topical tirbanibulin or vehicle (placebo) ointment in a 1:1 ratio in two identically designed double-blind trials (351 patients per trial). Ointment was applied to a 25-cm2 contiguous area once daily for five consecutive days.
The researchers found that in trial 1, complete clearance occurred in 44% and 5% of patients in the tirbanibulin and vehicle groups, respectively, at day 57; in trial 2, the corresponding percentages were 54% and 13%.
Compared with the vehicle groups, the tirbanibulin groups had significantly higher percentages of patients with partial clearance. Among patients who had had a complete response to tirbanibulin, the estimated percentage with recurrent lesions was 47% at one year. The most common local reactions to tirbanibulin were erythema and flaking or scaling (91% and 82%, respectively).
Larger and longer trials are necessary to determine the effects and risks of tirbanibulin therapy among patients with actinic keratosis,” the authors write.
Several authors disclosed financial ties to biopharmaceutical companies, including Athenex, which developed tirbanibulin and funded the study.
Phase 3 Trials of Tirbanibulin Ointment for Actinic Keratosis
Andrew Blauvelt, Steven Kempers, Edward Lain, Todd Schlesinger, Stephen Tyring, Seth Forman, Glynis Ablon, George Martin, Hui Wang, David L Cutler, Jane Fang, Min-Fun R Kwan, for the Phase 3 Tirbanibulin for Actinic Keratosis Group
Published in the New England Journal of Medicine on 11 February 2021
The tubulin polymerization and Src kinase signaling inhibitor tirbanibulin is being investigated as a topical treatment for actinic keratosis, a precursor of squamous-cell carcinoma.
In two identically designed double-blind trials, we randomly assigned, in a 1:1 ratio, adults with actinic keratoses on the face or scalp to receive either topical tirbanibulin or vehicle (placebo) ointment. The ointment was applied by the patients to a 25-cm2 contiguous area containing four to eight lesions once daily for 5 consecutive days. The primary outcome was the percentage of patients with a complete (100%) reduction in the number of lesions in the application area at day 57. The secondary outcome was the percentage of patients with a partial (≥75%) reduction in the number of lesions within the application area at day 57. The incidence of recurrence was evaluated at 1 year. Local reactions were scored with the use of 4-point scale (ranging from 0 [absent] to 3 [severe]).
A total of 702 patients were enrolled in the two trials (351 patients per trial). Complete clearance in trial 1 occurred in 44% of the patients (77 of 175) in the tirbanibulin group and in 5% of those (8 of 176) in the vehicle group (difference, 40 percentage points; 95% confidence interval [CI], 32 to 47; P<0.001); in trial 2, the percentages were 54% (97 of 178 patients) and 13% (22 of 173), respectively (difference, 42 percentage points; 95% CI, 33 to 51; P<0.001). The percentages of patients with partial clearance were significantly higher in the tirbanibulin groups than in the vehicle groups. At 1 year, the estimated percentage of patients with recurrent lesions was 47% among patients who had had a complete response to tirbanibulin. The most common local reactions to tirbanibulin were erythema in 91% of the patients and flaking or scaling in 82%. Adverse events with tirbanibulin were application-site pain in 10% of the patients and pruritus in 9%, all of which resolved.
In two identically designed trials, tirbanibulin 1% ointment applied once daily for 5 days was superior to vehicle for the treatment of actinic keratosis at 2 months but was associated with transient local reactions and recurrence of lesions at 1 year. Trials comparing tirbanibulin with conventional treatments and that have longer follow-up are needed to determine the effects of tirbanibulin therapy on actinic keratosis.
Full Medical Xpress report (Open access)
New England Journal of Medicine study (Restricted access)
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