VALCHLOR® (mechlorethamine) gel is an alkylating drug indicated for the topical treatment of Stage IA and IB mycosis fungoides–type cutaneous T-cell lymphoma (MF-CTCL) in patients who have received prior skin-directed therapy

Post hoc, by-time analysis of the clinical trial provides additional insight


Taking a look at the response rate of VALCHLOR® (mechlorethamine) gel:

The details below are not highlighted in the full Prescribing Information for VALCHLOR and should not be interpreted as demonstrating better efficacy than what is in the product labeling.

By-time data from 130 VALCHLOR patients from the original noninferiority trial was collected, providing complementary information to the traditional ORR. The by-time analysis measures the proportion of CAILS/SWAT responders at each time point in the study, whereas the traditional ORR shows the proportion of responders throughout the study, without visibility to when the response occurred or if it was lost. Patients in the original ORR analysis were required to have a response at two consecutive visits. The reanalysis evaluated patients at all time points regardless of the response observed at prior visits.

By-time analysis provides visibility into1:

  • Initial response rate and time to maximum response to treatment
  • Lost responder status and early termination patients after an initial response
  • New unconfirmed responders who exceed the 50% threshold at the end of the study

Examples of varying response time for individual patients used in the by-time analysis

CAILS % change from baseline (visits 1 through 9)2

Visit (over 12 months) 1 2 3 4 5 6 7 8 9
Pt. 1 -50 -100 -100 -100 -100 -100 -100 -100 -100
Pt. 2 -50 -75 -79.2 -91.7 -75 -87.5 -79.2 -79.2 -87.5
Pt. 3 -50 -66.7 -50 -50 -66.7 -50 -50 -83.3 -50
Pt. 4 -38.9 0 -13 -38.9 -50 -38.9 -66.7 -70.4 -51.9
Pt. 5 -32.6 -41.3 -76.1 -34.8 -28.3 -8.7 -50 -69.6 73.9
Pt. 6 -20 -40 -24 -52 -76 -68 -48 -72 -100
Pt. 7 -28.6 -32.1 -35.7 -28.6 -21.4 -35.7 -75 -71.4 -64.3
Pt. 8 -32.3 -38.7 -48.4 -48.4 -58.1 -74.2 -83.9 -87.1 -100
Pt. 9 -8.8 -20.6 0 -14.7 -5.9 -5.9 -26.5 -58.8 -79.4
≥50% response <50% response

Response rates over time1

Post Hoc By-Time Analysis of CAILS Response1*

Maximum Response: 10 months

Maximum response to treatment was seen at 10 months per CAILS score

Post Hoc By-Time Analysis of SWAT Response1*

Maximum Response: 8-10 months

Maximum response to treatment was seen at an 8- to 10-month plateau per SWAT score

Analysis Limitation: Data are descriptive only and without P values; therefore, this information should be cautiously interpreted.

Patients with data curve: only patients who had data available at each time point were included in this by-time post hoc analysis. Only results from visits 1 to 8 are represented in the figures above.1

The by-time analysis is a post hoc analysis that shows the proportion of patients responding for each visit in the study, calculated as the ratio of the number of patients with a ≥50% reduction in symptoms divided by the number of patients contributing data at each timepoint (patients with data curve) or all patients randomized (ITT curve).1

*49 patients discontinued treatment early. To account for selection bias, 5 patients who terminated early due to lack of efficacy and/or disease progression were counted as nonresponders in the primary analysis (patients with data). The secondary analysis (ITT) considers all 49 early termination patients as nonresponders and includes all 130 randomized patients for each data point.1

Hear experts discuss the by-time analysis

The correlation between these pharmacological data and clinical efficacy has not been established.

An increasing proportion of patients responded when continuing therapy for longer1