20 Proposals on Methotrexate Dosing in Patients with Psoriasis Discussed

Astrid van Huizen, MD

A consensus was reach on 20 of the 21 proposals regarding dosing of methotrexate in patients with psoriasis, which investigators of the eDelphi study believed could be use to “harmonize the treatment” of the drug in affected patients.

As one of the 4 available systemic treatments, methotrexate has been prescribed for psoriasis for over 6 decades, and is also used prominently in the rheumatology field.

However, methotrexate was approved by the US Food and Drug Administration before the introduction of dose ranging studies. As such, a clear dosing regimen for the treatment is lacking.

As such, investigators led by Astrid van Huizen, MD, Department of Dermatology at the University of Amsterdam, conducted the eDelphi study to reach international consensus on the dosing of methotrexate for treating patients with psoriatic disease.

The study consisted of 3 sequential survey rounds that were conducted in September 2020, November 2020, and February 2021. An online consensus meeting occurred following the last survey round in June 2021.

A total of 4500 members of the Skin Inflammation and Psoriasis International Network (SPIN) were invited to participate. Additional emails were sent to 108 national representatives and 35 scientific committee members of the network.

From September 2020 to March 2021, a total of 180 participants worldwide- 30.6% of whom resided in non-Western countries- completed the 3 survey rounds.

Participants voted on 21 individuals proposals on a 9-point scale, 1-3 indicated “disagree”, 4-6 “neither agree nor disagree”, and 7-9 being “agree”.

A majority of participants worked at a university hospital (53.9%) and were experienced in treating patients with psoriasis with methotrexate (91.6%), with more than 10 years of experience.

Among the 251 participants included in the study, 180 (71.7%) completed all 3 survey rounds, and 58 participants (23.1%) joined the conference meeting.

No consensus was achieved regarding increased dosage of folic acid when increasing the dosage of methotrexate, with members of the study citing a lack of conclusive evidence.

However, a consensus was met regarding children and methotrexate dosing, though most proposals were based on studies from rheumatology due to a lack of evidence in dermatology.

The most widely discussed proposals involved patients with frailty. Elderly individuals, individuals with kidney renal dysfunction, liver disorders (eg, nonalcoholic steatohepatitis), ulcerative colitis, history of hepatitis, lack of compliance, gastritis, diabetes, previous cancer, and congestive heart failure were included in the added definition of patients with frailty.

Furthermore, the term “patients with frailty” was replaced with “vulnerable patient”, which excluded elderly patients and patients with impaired kidney function.

While a consensus was achieved in the study, investigators believed that additional high-quality studies were needed to support the proposals offered by the group.

“Other consensus projects can focus on the screening and monitoring of this drug, how often and which tests should be performed, and whether special precautions are needed in children, elderly individuals, and other subpopulations,” the team wrote.

The statement, "International eDelphi Study to Reach Consensus on the Methotrexate Dosing Regimen in Patients With Psoriasis," was published online in JAMA Dermatology.