SAN DIEGO – A split dose of methotrexate (MTX) given orally once per week showed significantly higher efficacy in patients with rheumatoid arthritis at 16 weeks, compared with a single MTX dose weekly, according to new research. By 24 weeks, efficacy measures were similar for both groups.
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However, fewer patients in the split-dose group needed additional disease-modifying antirheumatic drugs (DMARDs) to control disease activity.
MTX is a highly utilized, inexpensive drug for RA, but only about 30% of patients can achieve low disease activity or remission on MTX monotherapy, said Varun Dhir, MD, MBBS, of the Postgraduate Institute of Medical Education and Research, Chandigarh, India. He co-authored and presented the research at the annual meeting of the American College of Rheumatology.
Part of the problem is that “oral methotrexate absorption from the gut reduces as the doses go up,” Dr. Dhir noted, because the transport mechanism gets saturated. MTX delivered subcutaneously is one way to improve efficacy, but patients can be needle-averse, and in some countries, like India, pre-filled syringes are not available, he said.
There is pharmacokinetic data dating back 20 years that suggest split-dose MTX could be more efficacious. “However, there are no randomized controlled trials to date, and the guidelines therefore are silent on this approach,” Dr. Dhir said.
To address this question, Dr. Dhir and colleagues recruited patients with RA from six centers across India. Patients were aged 18-60 years, seropositive (rheumatoid factor or anti-citrullinated protein antibodies), and had a disease duration of 5 years or fewer. Patients had active disease, defined as at least four tender joints and at least two swollen joints, and were not taking any DMARDs except for hydroxychloroquine and/or low-dose prednisolone.
A total of 253 patients were randomly assigned to a single 25-mg dose or a split-dose of MTX once weekly (10 mg in the morning and 15 mg in the evening on the same day). The primary outcome was a European Alliance of Associations for Rheumatology (EULAR) good response at 24 weeks. At the 16-week mark, if patients had not achieved low disease activity based on a 28-joint Disease Activity Score (DAS28) greater than 3.2, a blinded assessor could add either leflunomide or sulfasalazine to the continued MTX therapy.
At baseline, there was no difference between the groups’ DAS28, but after 16 weeks, DAS28 was significantly lower in the split-dose group, compared with the single-dose group (4.4 vs. 5.1; P < .001), and a higher percentage of patients in the split-dose group had a EULAR good response.
About three-quarters (76.6%) of patients in the split-dose group experienced an improvement of at least 20% in ACR response criteria (ACR20), compared with 52% in the single-dose group. The split-dose group also had higher proportion of patients achieving ACR50 and ACR70.
About one-third of the split-dose group (35%) added an additional DMARD at 16 weeks, compared with 54.5% of the single-dose group (P = .005).
After 24 weeks, DAS28 scores remained lower in the split-dose group (4.1 vs. 4.5; P = .03), but there were no other differences in treatment responses. Health Assessment Questionnaire scores were the same between both groups at 16 and 24 weeks.
The primary outcome was not met, although Dr. Dhir noted a flaw in the study design that could have affected the results. By allowing patients to add additional DMARDs at 16 weeks, “there were two factors which were affecting the primary outcome” at 24 weeks, he told this news organization. “I feel there was a robust result at least at 16 weeks.”
While there were no major adverse events, the split-dose group had higher rates of transaminitis (elevated liver enzymes) during the study, and low white blood cell count was higher in the single-dose group at 24 weeks. There was no difference in MTX intolerance between the two groups.
“It looks like [the split-dose group] gets out of the block faster. It’s a faster effect,” although the other group did catch up, Janet Pope, MD, MPH, of Western University, London, Ont., said in an interview. She was not involved with the research. Two positive results were the earlier ACR responses in the split-dose group as well as fewer patients in that same group needing to add another DMARD to therapy.
“In my opinion, if it’s equal cost, why not try it and see?” she said.
In a separate presentation referring to the abstract, Joan Bathon, MD, director of rheumatology at Columbia University, New York City, noted that these results align with ACR 2021 recommendations. Dr. Bathon was not involved with this study but was on the writing committee establishing those 2021 guidelines.
“The recommendation – with low certainty of evidence – was that for patients who are intolerant to MTX, that split-dose of oral MTX is worth trying before you switch to a different DMARD,” she said. “I think these data support that concept.”
Dr. Dhir and Dr. Bathon had no relevant financial relationships. Dr. Pope disclosed financial relationships with AbbVie/Abbott, Amgen, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Fresenius Kabi, GlaxoSmithKline, Janssen, Mallinckrodt, Novartis, Organon, Pfizer, Sandoz, and Viatris.
A version of this article first appeared on Medscape.com.