FDA approves diclofenac for managing OA pain

FDA has approved a new indication for diclofenac (Zorvolex, Iroko Pharmaceuticals) capsules, a nonsteroidal anti-inflammatory drug (NSAID), for the management of osteoarthritis pain (OA).

Zorvolex was approved by FDA in October 2013 for the treatment of mild-to-moderate acute pain in adults.

“The use of NSAIDs is likely to increase as the US population continues to age and experience painful conditions that are more common among older adults,” said Clarence Young, MD, chief medical officer, Iroko Pharmaceuticals.

The drug’s approval for the management of OA pain was supported by data from a 12-week, multicenter, randomized, double-blind, parallel-group, placebo-controlled trial that enrolled 305 patients, aged 41 to 90 years, with osteoarthritis of the hip or knee. Half of the patients were between aged 61 to 90 years. Participants were randomly assigned to Zorvolex 35 mg 3 times daily or 35 mg twice daily, or placebo. The Supplemental New Drug Application (sNDA) also included data from a 12-month open-label safety study that enrolled 602 patients.

Zorvolex was the first FDA-approved low dose NSAID developed using proprietary SoluMatrix Fine Particle Technology. Zorvolex contains diclofenac as submicron particles that are approximately 20 times smaller than their original size. The reduction in particle size provides an increased surface area, leading to faster dissolution. By using this technology, the dose can be lowered without delaying absorbtion. 

“This allows for the treatment of patients with a low-dose NSAID that results in lower overall systemic exposure,” Dr Young said.

Zorvolex was developed to align with recommendations from FDA and several professional medical organizations that NSAIDs be used at the lowest effective dose for the shortest possible duration consistent with individual patient treatment goals. The prevalence of dose-related serious gastrointestinal adverse events with oral NSAIDs is 15% and at least twice as likely in older patients.

“There is an unmet need in pain treatment for options that can be given at a lower dose to potentially reduce the risk of treatment-related adverse events,” Dr Young explained.

The wholesaler acquisition cost (WAC) of Zorvolex is $2.50 per capsule, with a daily price of $7.50.

Approximately 27 million US adults are affected by osteoarthritis (OA) and it is the most common type of arthritis. OA is one of the most common causes of disability, and inadequate pain control can lead to joint stiffness that may impair mobility for patients. Since OA is a chronic condition, patients are often treated with NSAIDs to manage their pain for an extended period of time. In fact, research shows that 50% of OA patients are treated with an NSAID.

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