Sorrento Therapeutics Inc. unit SCILEX Pharmaceuticals Inc. will merge with fellow pain management drug developer Semnur Pharmaceuticals Inc., Sorrento said March 22.

The merger will form a new company called Scilex Holding Co., in which Sorrento will now hold a 58% equity stake.

Both the California-based drugmakers develop non-opioids for pain. Scilex's ZTlido is a lidocaine topical patch and received U.S. Food and Drug Administration approval for post-shingles pain in February 2018. Semnur's non-opioid corticosteroid gel injection, SP102, for a type of spinal pain, is currently in phase 3 trials.

Semnur CEO Jaisim Shah will become the CEO of the newly formed Scilex Holding, Sorrento's press release stated.

"This transaction is highly synergistic," Sorrento CEO and Chairman Henry Ji said. "Scilex has built up a commercial organization ... while Semnur has a very exciting phase 3 compound ... Sorrento is now well-positioned to address an approximately $63 billion pain therapeutics market."