FDA Approves Nonopioid ZTlido Patch for PHN Pain

Lidocaine topical system offers better adhesion, company says

The FDA has approved a lidocaine topical system (ZTlido, Sorrento Therapeutics, Inc.), 1.8%, for the relief of pain associated with post-herpetic neuralgia (PHN) that Sorrento bills as “a major advancement in analgesics” because of improved adhesion.

“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 health care providers, patients, and payers who are looking for an effective and efficient, local pain treatment,” said Dr. Henry Ji, Chairman and CEO of Sorrento and its subsidiary Scilex Pharmaceuticals Inc.

ZTlido’s anhydrous topical system is based on technology that is designed to achieve superior adhesion and drug delivery efficiency. ZTlido requires only 36 mg per topical system versus 700 mg per patch of Lidoderm (lidocaine patch 5%), the U.S. reference product, to achieve the same therapeutic dose of drug.  The safety and efficacy of ZTlido was bridged to Lidoderm in comparative pharmacokinetic studies that demonstrated bioequivalence between products.

According to an FDA report on the product quality of transdermal drug delivery systems, adhesion was the most widely reported quality defect of transdermal patches. With a need for improved patch adhesion systems, ZTlido was specifically designed to maintain optimum skin contact throughout the 12-hour administration period.

ZTlido adhesion performance was demonstrated in a clinical study in 54 healthy volunteers where 47 subjects (87%) had adhesion scores of 0 (at least 90% adhered; essentially no lift off the skin) for all evaluations performed every three hours during the 12 hours of administration, and seven subjects (13%) had adhesion scores of 1 (75% to less than 90% adhered; some edges only lifting off the skin) for at least one evaluation, and no subjects had scores of 2 or greater (less than 75% adhered).  In the same study, 49 subjects (91%) presented with a score of 0 at the end of the 12-hour administration period.  The remaining five subjects had a score of 1.

ZTlido is comprised of a nonaqueous adhesive material containing 1.8% lidocaine, which is applied to a nonwoven polyester felt backing and covered with a polyethylene terephthalate film release liner. The release liner is perforated in the middle and removed prior to application to the skin. The size of the topical system is 10 cm × 14 cm x 0.08 cm thick. ZTlido is indicated for relief of pain associated with PHN. It should be applied only to intact skin.

During or immediately after treatment with ZTlido, the skin at the site of application may develop blisters, bruising, burning sensation, depigmentation, dermatitis, discoloration, edema, erosions, erythema, exfoliation, flushing, irritation, papules, petechia, pruritus, vesicles, or may be the locus of abnormal sensation. These reactions are generally mild and transient, resolving spontaneously within a few minutes to hours.

Allergic and anaphylactoid reactions associated with lidocaine, although rare, can occur. They are characterized by angioedema, bronchospasm, dermatitis, dyspnea, hypersensitivity, laryngospasm, pruritus, shock, and urticaria. If they occur, they should be managed by conventional means.

Systemic adverse reactions following appropriate use of ZTlido are unlikely, due to the small dose absorbed.

Source: Sorrento; February 28, 2018.