The US Food and Drug Administration (FDA) approved Pfizer’s Troxyca ER (oxycodone hydrochloride and naltrexone hydrochloride) in August 2016. The extended-release capsules are designed to reduce abuse when crushed and administered by oral and intranasal routes.
However, according to New Jersey-based Elite Pharmaceuticals, Pfizer’s decision to designate Troxyca ER as ‘discontinued’ is preventing other firms from manufacturing generic versions of the sequestered naltrexone technology with extending release oxycodone.
“Pfizer has three and a half years exclusivity – three years exclusivity for the work they’ve done and six months for paediatric – until then, nobody else can enter the market,” Elite CEO Nasrat Hakim told investors.
“If they’re not making it and they went straight to discontinue, we cannot [undertake a bioequivalence study]…they are effectively stopping us from entering the market,” he added.
Elite’s head of business development, Chris Dick, said that from a drugmaker’s perspective, the situation is rare: “I’m not aware of this ever happening before, where somebody got a product approved, and before they launched it, they discontinued it. We are hugely interested why they did that.”
“It is confusing. How could a product be put on the market, without doing a NDA (new drug application) 505(b)(2), which would be very expensive?” he added.
The FDA defines a 505(b)(2) application as an NDA relying on one or more investigations “not conducted by or for the applicant and for which the applicant has not obtained a right of reference or use from the person by or for whom the investigations were conducted.”
“If the FDA wants to encourage ADF (abuse-deterrent products) – and this is a compelling one we believe – then maybe they could give us some guidance on how we could effectively do a generic of that product,” Dick told us.
According to Pfizer, the decision to halt production of Troxyca ER stems from the availability of comparable, commercialised products on the market: “Pfizer made the decision not to introduce another oxycodone medicine as there are several abuse-deterrent oxycodone treatment options available to patients,” a spokesperson told us.
Opioid abuse has become an epidemic in the US, with approximately 115 Americans dying after overdosing on opioid daily, according to the Disease Control and Prevention. The FDA confirmed its support of generic abuse-deterrent opioid development with the release of a final guidance for drugmakers last year.
“We remain deeply committed to addressing unmet medical needs and continue our pursuit of scientific innovation for people living with chronic pain,” the Pfizer spokesperson added.
Generic drug development
In the investor call, Hakim said Elite is advancing a number of other generic candidates towards commercialisation: “Elite has six ANDAs (abbreviated new drug applications) submitted to the FDA, we expect to start seeing the first approval soon and next quarter, and start launching these products as we go along.”
In July 2017, we reported that unsatisfactory bioequivalence data had prompted Elite to halt trials of its reformulated opioid painkiller SequestOx (naltrexone and oxycodone hydrochloride), but Hakim has since told investors the firm is ‘moving forward’ with the candidate.
“For now, we await a response from the FDA regarding the studies required. After that, we will diligently move forward for the submission, and we continue to develop other generics with our partners and by ourselves,” he added.