The FDA finally gave its nod late Tuesday afternoon to Merck & Co. Inc.'s analgesic reversal agent sugammadex, the approval coming nearly eight years after the original new drug application was submitted.

Branded Bridion, the injectable agent is indicated to reverse the effects of neuromuscular blockade induced by rocuronium bromide and vecuronium bromide, which are used during certain types of surgery in adults. Neuromuscular blocking drugs cause temporary paralysis by interfering with the transmission of nerve impulses to the muscle and are used, for example, to paralyze the vocal cords during tracheal intubation.

Sugammadex belongs to a class of medicines known as selective relaxant-binding agents, designed to be safer than traditional reversing agents. Data from three phase III studies involving 456 participants showed that the return to recovery time was faster in the sugammadex groups vs. comparator groups. Most patients recovered within five minutes of sugammadex use.

Those data, submitted in 2008 by Schering-Plough Corp. (later acquired by Merck), were sufficient to convince regulators in Europe, where sugammadex has been marketed as Bridion since 2008. Merck reported total sales of Bridion reaching $340 million in 2014, according to Cortellis Competitive Intelligence.

Convincing the FDA, however, has proved a much tougher task. The agency issued a not-approvable letter in 2008, citing the need for a hypersensitivity study. Merck conducted that hypersensitivity trial, but in its 2013 complete response letter (CRL), the FDA took issue with "operational aspects" of that study. (See BioWorld Today, Sept. 24, 2013.)

A third CRL came in April. Kenilworth, N.J.-based Merck disclosed during its quarterly earnings call that the FDA wanted more data on potential allergic reactions.

Good news finally came last month, when the FDA's Anesthetic and Analgesic Drug Products Advisory Committee gave a unanimous thumbs-up, recommending approval for sugammadex as a safe agent for reversing the effects of muscle relaxants used during surgery. Final FDA approval came a few days ahead of the Dec. 19 PDUFA date.

Sugammadex has been evaluated in a randomized, double-blind, parallel-group, repeat-dose trial involving 299 patients, with data showing that one patient suffered an anaphylactic reaction. The FDA noted that clinicians should be aware of the possibility of a hypersensitivity reaction or anaphylaxis. The agency also said patients receiving sugammadex should be monitored for hemodynamic changes, given that cases of bradycardia were observed within minutes of administration.

In separate news, the FDA approved an expanded age indication for Gardasil (human papillomavirus 9-valent vaccine, recombinant) to include use in males, ages 16 through 26, for the for the prevention of anal cancer caused by human papillomavirus (HPV) types 16, 18, 31, 33, 45, 52 and 58; precancerous or dysplastic lesions caused by HPV types 6, 11, 16, 18, 31, 33, 45, 52 and 58; and genital warts caused by HPV types 6 and 11.