King Pharmaceuticals and its partner, Pain Therapeutics, plan to resubmit their NDA for the abuse-resistant pain drug Remoxy by the middle of next year, following a recent meeting with FDA, according to a July 7 announcement.

The drug makers met with FDA on July 2 to discuss a "complete response" letter they received for Remoxy (long-acting oxycodone) last December, asking for more assurance that the formulation does, in fact, hold firm against common abuse tactics. King and Pain anticipate it will take about a year to generate the required six-months of stability data and prepare the submission, although no additional clinical trials are needed.

Pain's chief executive, Remi Barbier, attempted to downplay the setback by describing the request for stability data as an extra cautious step to ensure the drug "works as advertised." He likened it to checking the expiration date and packaging on a box of cereal. How the drug degrades over time is one factor that is being evaluated, Barbier explained.

Given cases of abuse linked to Purdue Pharma's pain drug OxyContin , a tamper-resistant formula would be a welcome addition on the market. But understanding just how abuse-deterring formulations stave off misuse is a challenging concept to prove to the FDA, according to recent remarks made by John Jenkins, who heads FDA's Office of New Drugs. However, this appears to be more of a road bump for drug makers than the agency's push to establish a class-wide Risk Evaluation and Mitigation Strategy for long-acting opioids, which regulators have made clear is not delaying approvals (Also see "Opioids Pending At FDA Held Up By Anti-Abuse Claims, Not REMS Planning" - Pink Sheet, 8 June, 2009.).

"Defining an abuse resistant formulation - for academics, us or FDA - is trying to define a very intangible thing, like the Supreme Court justices trying to define pornography - everyone knows what it is when they see it, but it's hard to pin down in words," Barbier said.

After receiving the complete response letter, Pain handed its baton to King to take over regulatory responsibilities that will see Remoxy through to approval. Under the initial partnership formed in 2005, Pain agreed to head R&D efforts and King would commercialize the drug. Pain also will collect a 15 percent royalty on product sales to start, jumping to a 20 percent royalty payment once the drug hits the $1 billion mark.

For King, a commercial launch looks to be smooth sailing once the drug gains an FDA OK, since Remoxy fits with its currently marketed specialty pain products being promoted by about 500 sales reps.

King also promotes the pain products Avinza (morphine sulfate extended release) and Flector Patch . Flector Patch continues to see prescriptions grow, despite a slight decrease in the drug maker's overall revenues for the first quarter 2009 at $429 million compared to $432 million the same quarter last year (Also see "FDA Class-Wide REMS Meeting Won’t Deter Embeda Approval, King Believes" - Pink Sheet, 11 May, 2009.).

More than a side stitch for Pain

But the filing setback looks to be a much greater threat to Pain, which is largely relying on Remoxy to become a $1 billion product, Standard & Poor's health care analyst Herman Saftlas said. Pain execs point out that Remoxy could become the first abuse-resistant pain formula to hit the market - but first it has to win FDA approval.

By contrast, King is already a significant player in the pain market and is awaiting an FDA decision on its abuse-resistant oral morphine drug Embeda , which it acquired through the Alpharma deal announced at the end of last year (Also see "King’s Dogged Pursuit of Alpharma Comes Up Aces" - Pink Sheet, 24 November, 2008.). Through the deal that valued Alpharma at about $1.6 billion, King also gained Flector Patch and Kadian (morphine sulfate extended-release), which it had to divest to avoid cannibalizing sales of its Avinza.

"For Pain Therapeutics, the whole business is basically centered on Remoxy, but King has a lot of other things on their plate; they're a more diversified company," Saftlas said. King also markets the muscle skeletal relaxant Skelaxin and the antihypertensive Altace (ramipril), which continues to take a hit from generics after going off patent in 2007, among other products.

Still, Saftlas noted that both companies have made a significant investment in Remoxy, and that neither is likely to walk away from the drug. Taking into account the new filing timeline and the additional six-month FDA review, the drug will probably not start to generate sales until 2011, he speculated. This shortens the amount of time Remoxy will have on the market before OxyContin generics make their entrance, which could happen as early as 2013, Saftlas also said.

-Carlene Olsen (c.olsen@elsevier.com)

Now Who Needs a Painkiller? King and Pain Therapeutics Face a Remoxy Setback

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