Overall, 88 of 297 children (30%) experienced treatment failure, including 57 of 212 (27%) on infliximab and 31 of 85 (36%) on adalimumab. Overall, 40 of 156 children (26%) on combination therapy and 48 of 141 (34%) on monotherapy experienced treatment failure.
Kaplan Meier analysis of the overall population showed a nonsignificant trend toward lower event rates with combination therapy (hazard ratio, 0.69; 95% confidence interval, 0.45-1.05; P = .08).
After stratification by TNFi, there was no difference in time to treatment failure among infliximab initiators between combination and monotherapy (HR, 0.93; 95% CI, 0.55-1.56; P = .78). In contrast, among adalimumab initiators, combination therapy was significantly associated with a longer time to treatment failure (HR, 0.40; 95% CI, 0.19-0.81; P = .01).
There was a nonsignificant trend toward lower development of anti-drug antibodies with combination therapy (risk ratio, 0.72 with infliximab and 0.71 with adalimumab). This trend is in line with adult studies and adds substantially to the pediatric literature on this topic, the researchers noted.
No differences in patient-reported outcomes were observed. There were slightly more adverse events with combination therapy, as expected, but fewer serious adverse events.
Shared decision-making
Dr. Kappelman noted that the study was not designed to answer the question of which is better – adalimumab plus methotrexate or infliximab alone. “This is an area for future research. At this point, we believe it is an individualized decision, and appropriate counseling is needed to support shared decision-making,” he said.
Nor was the trial designed to evaluate the role of proactive therapeutic drug monitoring. However, proactive TDM is endorsed in the ImproveCareNow Model IBD Care guidelines and was considered standard of care at the 35 study sites.
The findings “suggest strong consideration of using combination therapy for pediatric Crohn’s disease patients initiating adalimumab but not infliximab,” Dr. Kappelman and colleagues said.
“Dissemination and implementation of these findings should lead to improved outcomes in this patient population, including consideration of de-implementation of combination therapy in infliximab treated patients,” they added.
The decision about which approach to use is still very dependent on patients and their providers, Dr. Kurowski said.
“The study shows that you can safely use infliximab as monotherapy, with low risk of antibody formation, while utilizing proactive therapeutic drug monitoring and dose optimization. The study also shows that adalimumab in combination with low-dose methotrexate can be strongly considered when needed.”
The researchers’ standardization of methotrexate doses by weight “is another significant contribution and provides a guide for clinicians,” Dr. Kurowski added.
The study was funded by grants from the Patient-Centered Outcomes Research Institute, the Helmsley Charitable Trust, and National Institute of Arthritis and Musculoskeletal and Skin Diseases. Dr. Kappelman has consulted for AbbVie, Janssen, Pfizer, Takeda, and Lilly; holds shares in Johnson & Johnson; and has received research support from Pfizer, Takeda, Janssen, AbbVie, Lilly, Genentech, Boehringer Ingelheim, Bristol-Myers Squibb, Celtrion, and Arena Pharmaceuticals. Dr. Kurowski reports no relevant financial relationships.
A version of this article first appeared on Medscape.com.