Poor early response to methotrexate portends inadequate long-term outcomes in patients with moderate-to-severe psoriasis: Evidence from 2 phase 3 clinical trials

BACKGROUND:

Most methotrexate-treated psoriasis patients do not achieve a long-term PASI75 (75% reduction from baseline PsoriasisArea and Severity Index score) response. Indications of nonresponse can be apparent after only 4 weeks of treatment.

OBJECTIVE:

To develop a prediction rule to identify patients unlikely to respond adequately to methotrexate.

METHODS:

Patient-level data from CHAMPION (NCT00235820, N = 110) was used to construct a prediction model for week 16 PASI75 by using patient baseline characteristics and week 4 PASI25. A prediction rule was determined on the basis of the sensitivity and specificity and validated in terms of week 16 PASI75 response in an independent validation sample from trial M10-255 (NCT00679731, N = 163).

RESULTS:

PASI25 achievement at week 4 (odds ratio = 8.917) was highly predictive of response with methotrexate at week 16. Patients with a predicted response probability <30% were recommended to discontinue methotrexate. the rates of week 16 pasi75 response were 65.8% and 21.1% (p >< .001) for patients recommended to continue and discontinue methotrexate, respectively.>

LIMITATIONS:

The CHAMPION trial excluded patients previously treated with biologics, and the M10-255 trial had no restrictions.

CONCLUSION:

A prediction rule was developed and validated to identify patients unlikely to respond adequately to methotrexate. The rule indicates that 4 weeks of methotrexate might be sufficient to predict long-term response with limited safety risk.