FDA Approves Lidocaine Patch 1.8% for Post-Herpetic Neuralgia

The US Food and Drug Administration (FDA) has approved a lidocaine 1.8% topical patch (ZTlido) for the relief of pain associated post-herpetic neuralgia (PHN).

The patch, produced by Sorrento Therapeutics subsidiary Scilex Pharmaceuticals, is unique in its adhesion tech, which allows for 12-hour wear with effective delivery of the medication, including during exercise periods. It also utilized a much smaller dose of medication per patch compared to currently available products.

“ZTlido is a next-generation, branded lidocaine 1.8% patch,” Jeff Gudin, MD, the director of pain management and palliative care at Englewood Hospital and Medical Center in New Jersey and a scientific advisor for Scilex, told MD Magazine. “As a single-layered anhydrous patch, the product contains only 36 mg of lidocaine versus 700 mg in the reference 5% patch.”

The FDA utilized data from a clinical trial of 54 patients, in which 47 patients (87%) had adhesion scores of 0 (≥90% adhered, essentially no lift) for all evaluations at hours 3, 6, 9, and 12. Additionally, 7 subjects (13%) scored 1 (≥75% to <90% adhered, some edges lifted) for at least 1 evaluation, and no participants scored 2 or greater (<75% adhered).

The same study reported 91% (n =49) of patients with a score of 0 at hour 12.

“The thinner topical system showed improved adhesion, which is obviously necessary for efficacy and should more readily adhere to curved [joint] surfaces,” Gudin said. “The [FDA-] approved indication will be similar to the legacy patch post-PHN.”

In a 2016 study that measured the therapy’s absorption and was led by Gudin, investigators examined the plasma concentration of medicine that the patch administered over time under normal conditions, with heating, and with physical exercise. Levels were lower with exercise than under normal conditions, both peaking around 9 hours post-administration. Absorption levels spiked above 160 mg/mL when heat was applied but were shown to be reversible, returning to baseline after 20 minutes.

“The patch may offer possible advantages over the 5% lidocaine patch, including more efficient delivery of lidocaine, superior adhesion, and less residual left in the patch after normal use,” Gudin said.

“ZTlido was designed to solve a problem that is commonly reported with transdermal/topical patches: they don’t stay on. Based on the adhesion study results with ZTlido, we believe that ZTlido product will be welcomed by healthcare providers, patients and payers who are looking for an effective and efficient, local pain treatment,” Henry Ji, PhD, the chairman and CEO of Sorrento and Scilex, said in a statement. “We also intend to explore the expansion of ZTlido into additional indications and the underlining platform technology of ZTlido for other active pharmaceutical ingredients (APIs) and combinations of APIs. As demonstrated by the NDA approval for ZTlido, our team successfully executed on our development plan for the product and now, looks forward to executing on our commercial and strategic alliance plans as well.”

According to data from IMS, more than 100 million prescription lidocaine patches were sold in the US in 2017. The Sorrento product plans to hit the market some time in 2018, according to the company.

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