Further FDA crackdown on opioids could close market to generics
The FDA has struck a new blow in its battle to reduce abuse of opioid painkillers by restricting prescribing to patients in need of round-the-clock relief from severe pain and requiring new post-market research into addiction and other negative consequences of long-term use.
Added to the agency’s last broadside against these products – it announced in April that it would not approve any generic opioids that were not abuse-deterrent – the question is now whether it is any longer worthwhile for companies to attempt to enter this space.
The change affects all extended-release and long-acting opioid formulations intended to treat pain. The updated labelling states that long-acting opioids are indicated solely to manage severe pain requiring 24-hour, long-term opioid treatment for which alternative options are inadequate or otherwise unsuitable.
A new boxed warning will be added to the effect that chronic use of opioid analgesics during pregnancy can result in neonatal opioid withdrawal syndrome. Companies will also have to update their training programmes to teach doctors how to prescribe the pills.
As well as shrinking the potential patient population, the FDA is demanding that manufacturers conduct expensive long-term post-marketing clinical trials to assess the risks of misuse, abuse, increased sensitivity to pain, addiction, overdose and death.
Research into new painkillers of this type has yielded no new abuse-resistant compounds, and with no slackening in demand the agency has no choice but to keep the currently approved drugs on sale, in spite of their addictive nature. Its only option for harm reduction is to restrict their use, placing ever-stricter requirements on drug makers and doctors.
Naturally the new requirements will only exacerbate this. Candidates such as Pain Therapeutics’ Remoxy are already hanging in the balance. (Pfizer’s Remoxy trial boosts Pain despite lack of formal decision, August 19, 2013).
It would be unsurprising if the new rules turned out to be the last straw for Pain’s partner; Pfizer appears less than enthusiastic about the project and has already walked away from other opioids (Vantage Point – Political backing unlikely to help developers of tamper-resistant painkillers, August 9, 2012).
The main winner here is, as usual, Purdue Pharma. Its blockbuster OxyContin was relaunched in a new abuse-resistant formulation in 2010 and remains the only drug to gain the FDA’s nod as a specific abuse-resistant product. The earlier formulation is now off-patent, but any abbreviated NDA for a generic oxycodone based on this will automatically be turned down by the FDA.
It is possible that OxyContin will only be displaced from its pre-eminent position in the US market through the development of an entirely new class of painkiller.