Chlormethine gel may be more effective than ointment for mycosis fungoides

A post-hoc analysis of a key data set for chlormethine in mycosis fungoides showed that the gel formulation of the drug may be safer and more effective than the ointment, according to study findings.

The results of studies 201 and 202 led to the approval of chlormethine gel for patients with mycosis fungoides, which Christiane Querfeld, MD, of City of Hope Cancer Center and Beckman Research Institute in Duarte, California, and colleagues suggested is the most common cutaneous T-cell lymphoma.

“A post-hoc analysis of study 201 found interesting trends regarding improved efficacy of chlormethine gel vs. ointment and noted a potential association between dermatitis and clinical response,” the researchers wrote.

With that in mind, the group conducted a post-hoc analysis of study 202 to expand on this finding.

In study 201, participants received either the gel or the ointment for 12 months. In study 202, a higher concentration of the gel was administered for a 7-month extension.

The researchers used the Composite Assessment of Index Lesion Severity (CAILS) to assess disease severity outcomes. The study also used multivariable time-to-event analyses for associations between treatment frequency, response and skin-related adverse events.

A comparison between patients who only used chlormethine gel and those who switched from the ointment to the gel was made for time to response.

Results showed no association between frequency of treatment and skin response as assessed by CAILS. In addition, there were no differences in adverse events in the 201 and 202 study populations.

The researchers did observe an association between contact dermatitis and improvement in CAILS at the following visit (P < .0001).

Moreover, a significantly shorter time to response was observed among patients who used the gel in both studies (P < .05). Significantly higher response rates were also reported for patients using the gel in both 201 and 202.

“This post-hoc analysis shows that patients who initiated treatment using chlormethine gel had faster and higher responses compared with patients who initially used chlormethine ointment for 12 months,” the researchers concluded. “The development of contact dermatitis may be a potential prognostic factor for response.”