Etanercept (Enbrel) Correlated With Increased Growth in JIA

[Guest guest]

Etanercept Correlated With Increased Growth in JIA

http://www.medscape.com/viewarticle/732429

November 12, 2010 - Etanercept with or without methotrexate, but not

methotrexate alone, may help restore normal growth in children with juvenile

idiopathic arthritis (JIA), according to new research.

H. Giannini, DrPH, MSc, with the Cincinnati Children's Hospital

Medical Center, in Cincinnati, Ohio, and colleagues reported the findings in

the November 2010 issue of Arthritis & Rheumatism.

According to background information in the article, JIA is associated with

chronic inflammation, which results in impaired growth and development and

functional joint involvement. Shorter-term (2-year) studies have previously

shown that etanercept is safe and effective in patients with JIA.

In a separate analysis of the same study, etanercept was found to be safe

and effective at 3 years in 594 children with polyarticular or systemic JIA;

the physician's global assessment of disease activity and total active joint

scores improved and were sustained through 3 years in patients who continued

to receive medication.

In the current study, researchers assessed information from the same patient

registry to determine height, weight, and body mass index (BMI) at baseline

and each year thereafter for 3 years.

The mean height, weight, and BMI percentiles did not change significantly in

patients in the methotrexate-only group. However, patients receiving

etanercept demonstrated a 4.8% increase in mean height at year 3 vs

baseline. Likewise, patients receiving etanercept plus methotrexate showed a

mean height increase of 2.4, 3.3, and 5.6 percentile points at years 1, 2,

and 3, respectively.

Statistically significant increases from baseline in the mean weight

percentiles were observed at years 1, 2, and 3 in both the etanercept group

(7.4, 10.0, and 13.0 percentile points, respectively) and the

etanercept-plus-methotrexate group (2.9, 6.9, and 8.4 percentile points,

respectively).

BMI percentiles also increased significantly with etanercept: 9.6 to 13.8

percentile points with etanercept only and 2.1 to 5.2 percentile points with

etanercept plus methotrexate.

" Etanercept is very effective and may have slowed underlying, non-clinically

evident, pathophysiologic processes that reduced inflammation, whereas

methotrexate alone did not, and permitted growth to resume, " Dr. Giannini

told Medscape Medical News. He cautioned that this theory is speculative and

that the study does not prove this.

According to Dr. Giannini, methotrexate alone has been the standard of care

for nearly 20 years and is cheap and quite safe. " Etanercept is very

expensive, and some clinicians hesitate to begin treatment with it because

of the potential for malignancy, demyelination, infection, and other

reported adverse events (although we believe these risks to be low), " Dr.

Giannini said. " Still, height is important to kids and their parents. "

" The evidence in the current paper may encourage clinicians to initiate

etanercept earlier in the disease course to try to avert growth retardation,

and the psychosocial implications of being very short. "

Dr. Giannini pointed out that etanercept was the first anti-tumor necrosis

factor (TNF) agent approved for children with JIA. " Others now exist, but

long-term data in high numbers of patients, necessary to observe growth

resumption, have not been published. Nonetheless, smaller studies of

anti-TNFs have shown that both etanercept and infliximab have a positive

effect on growth. "

Yukiko Kimura, MD, with the ph M. Sanzari Children's Hospital at

Hackensack University Medical Center, in Hackensack, New Jersey, pointed out

that the finding that TNF blockers may improve growth in children with JIA

has not been previously documented in such a large number of patients.

" It makes sense that TNF blockers, which are known to be very effective in

reducing inflammation in children with JIA, would be associated with

improved growth in the children who took them, " she told Medscape Medical

News. Dr. Kimura was not listed as an author on the current study, although

she is a member of the Pediatric Rheumatology Collaborative Study Group,

which conducted the original trial.

The study was supported by Immunex Corporation, a wholly owned subsidiary of

Amgen Inc, and by Wyeth, which was acquired by Pfizer Inc. Drs. Giannini and

Kimura have disclosed no relevant financial relationships.

Arthritis Rheum. 2010;62:3259-3264.