Diclofenac 1% Gel Improves Knee Osteoarthritis Symptoms Regardless of BMI

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ATLANTA — Compared with placebo, among patients with knee osteoarthritis, diclofenac sodium gel (DSG) 1% improves pain, function, and stiffness, regardless of body mass index (BMI), according to results of a post hoc analysis presented at the 2019 American College of Rheumatology/Association of Rheumatology Professionals (ACR/ARP) Annual Meeting, held November 8 to 13, 2019, in Atlanta, Georgia.

This post hoc analysis included pooled data from 3 vehicle-controlled studies of DSG 1%, VOSG-PN-304, VOSG-PN-310, and VOSG-PN-316 in patients with osteoarthritis. The studies were of similar design and had similar efficacy end points, including Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) pain, function, and stiffness, and pain on movement (POM). Researchers analyzed efficacy data as change from baseline, stratified by 3 BMI groups (<25, ≥25-<30, and ≥30 kg/m²) at each visit (1, 4, 8, and 12 weeks).

The study cohort included the Intention to Treat efficacy population (all patients randomly assigned and treated) and the Modified Efficacy Subset (patients with no decline in POM score between screening and baseline visits, and a score between 0-1 on the WOMAC abridged pain index for the contralateral knee).

In all 3 BMI groups, improvement from baseline was greater with DSG 1% for all 4 efficacy measures compared with VOSG-PN-304, VOSG-PN-310, and VOSG-PN-316 for both populations. There were no significant differences in treatment effects among the 3 BMI groups for any of the 4 efficacy measures at any time during follow-up for either population.

At week 12 in the Intention to Treat population, the mean treatment effects for DSG 1% in the <25 BMI group (n=203), ≥25 to <30 (n=460), and ≥30 (n=751) kg/m² BMI, respectively, were 1.01, 0.87, and 0.79 for WOMAC pain (P =.94); 2.38, 2.97, 3.77 for WOMAC function (P =.78); 0.30, 0.47, 0.45 for WOMAC stiffness (P =.84); and 9.66, 7.13, 6.06 for POM (P =.71). For the Modified Efficacy Subset population, these scores were 0.75, 1.48, 1.23 for WOMAC pain (P =.69); 1.78, 4.99, 5.30 for WOMAC function (P =.40); 0.22, 0.68, 0.66 for WOMAC stiffness (P =.37); and 8.80, 10.39, 8.79 for POM (P =.91).

“There were no significant differences in efficacy between the 3 BMI groups, indicating that DSG 1% is efficacious regardless of BMI in patients with [osteoarthritis] of the knee and that dose adjustments based on body size are not necessary,” concluded the researchers.

Disclosure: All study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

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Reference

Block JA, Patel B, Garas SY. BMI has minimal effect on reduction of symptoms in patients with osteoarthritis of the knee treated with diclofenac 1% gel. Presented at: 2019 ACR/ARP Annual Meeting; November 8-13, 2019; Atlanta, GA. Abstract 2195.