Probuphine, a buprenorphine subdermal implant formulation for adults with opioid dependence has been given a green light by an FDA Advisory Committee (Panel). The Panel cited a favorable benefit-risk profile and an unmet need.

According to Titan Pharmaceuticals Inc., the FDA Panel voted 10 to 4 in favor, with one abstention. The Panel, which consists of 15 experts, advises the FDA on whether it should approve or turn down New Drug Applications (NDAs). The Agency does not have to follow its recommendations, but nearly always does.

Titan submitted an NDA for Probuphine in October of last year, referencing the approved sublingual buprenorphine formulations.

The FDA granted priority review designation for the new NDA with a target decision by the end of April 2013.

In December 2012, Titan and Braeburn Pharmaceuticals agreed on exclusive rights for the commercialization of Probuphine in the USA and Canada.

Kate Glassman-Beebe, Ph.D., executive vice president and chief development officer of Titan, said:

“We are pleased the Committee recognized the favorable benefit-risk profile of Probuphine and voted in strong favor of its approval. We look forward to working with the FDA to complete its review of Probuphine and remain committed to addressing the growing unmet needs in managing patients with opioid dependence.”

The Panel also voted on other aspects of the Probuphine implant:

  • Effectiveness – in favor by 10 votes to 5
  • Safety – in favor by 12 votes to 2, with 1 abstention
  • REMA (Risk Evaluation and Mitigation Strategy) – in favor by 5 to 4 with 6 abstentions. Titan says that the large number of abstentions is because the program is still being discussed with the FDA

US health authorities estimate that there are approximately 2.2 million Americans with opioid dependence.

  • About 20% of people with opioid dependence are addicted to illicit drugs, including heroin
  • The other 80% are addicted to prescription medications, including codeine, hydromorphone, methadone, hydrocodone, and oxycodone.

Until the turn of the millennium, medication-assisted therapies for opioid dependence could only be delivered from a limited number of facilities in the USA. After DATA 2000 (The Drug Addiction Treatment Act of 2000), patient access to medication-assisted treatments was expanded to medical offices – the result was a dramatic increase in the number of treatments. In 2011, over 1.2 million Americans were seeking treatment for opioid dependence.

Probuphine is an experimental subdermal implant which can deliver continuous and persistent, “around-the-clock blood levels of buprenorphine” for a period of six months, with just a single treatment. Patient compliance and retention is not an issue, as it is an implant the delivery of the drug is reliable, the patient does not have to remember to take the drug at certain times and frequencies.

According to Titan “Probuphine was developed using ProNeura™, Titan’s continuous drug delivery system that consists of a small, solid implant made from a mixture of ethylene-vinyl acetate (EVA) and a drug substance. The resulting construct is a solid matrix that is placed subdermally, normally in the upper arm in a simple office procedure, and removed in a similar manner at the end of the treatment period. The drug substance is released slowly and continuously through the process of dissolution resulting in a steady rate of release.”

Titan Pharmaceuticals says that several efficacy and safety trials on Probuphine have been performed, including a 163-patient, 24-week, placebo-controlled study in which patients on Probuphine had considerably less illicit opioid use, experienced fewer symptoms of withdrawal and craving, remained in treatment longer, and had greater overall improvements compared to those in the placebo group.

Titan shares rose in value to their highest level in four years on Friday, an increase of 36% to $1.67 in New York – the company’s biggest gain in one day since May 7th, 2009.

Experts believe that the implant, about the size of a matchstick, will bring in sales of at least $360 million in the USA annually in five years’ time.

A spokesperson for Titan Pharmaceuticals said:

“Opioid dependence is a rapidly growing public health concern and we remain committed to expanding the treatment options available to physicians and patients to manage this chronic condition.”

The number of people in the USA who end up in emergency department visits has risen considerably over the last ten years. Several states have been urging doctors to prescribe opioid painkillers with extreme care.

In January 2013, New York City Mayor, Michael Bloomberg, introduced new guidelines to prevent opioid painkiller abuse.

Opioid drug abuse does not only harm the addicted person, but is also associated with pharmacy burglaries and criminal misconduct.

Written by Christian Nordqvist