By Pat Anson, Editor
Imagine going to your doctor’s office and getting an implant put in your arm that delivers a steady flow of pain medication for six months.
No more pills. No more trips to the pharmacy. No more worries about your pain medication getting lost or stolen.
That’s the scenario a New Jersey drug maker envisions for its Probuphine implant – tiny rods about the size of a matchstick designed to be inserted subcutaneously under the skin of the upper arm.
Probuphine was developed by Braeburn Pharmaceuticals under a license agreement with Titan Pharmaceuticals (OTC: TTNP), which holds the rights to the implant technology. Both companies have applied to the Food and Drug Administration to have Probuphine approved to treat opioid addiction, but Braeburn’s long term goal is to also have the implant approved for chronic pain.
“We are definitely interested in talking to the FDA about the use of Probuphine in pain,” said Behshad Sheldon, President and CEO of Braeburn.
The active ingredient in Probuphine is buprenorphine, a weaker opioid that’s long been used as an addiction treatment drug sold under the brand name Suboxone. Buprenorphine is also used to treat chronic pain and comes in various forms – pills, patches and film strips – but none as long-acting as an implant.
The advantages of an implant are many. The dosage is controlled and there’s hardly any risk of abuse, diversion, or accidental overdose. You also never have to remember to take a pill.
“We believe a buprenorphine implant could be a really great clinical tool to treat pain,” Sheldon told Pain News Network. “There’s just a peace of mind aspect for the patients. The medicine’s on board and they don’t have to worry about it.”
“I personally would want a Lipitor implant, because I can’t manage to take it three days in a row,” she joked.
Probuphine’s path to the marketplace hasn’t been a smooth one. Braeburn and Titan were stunned in 2013 when the FDA denied approval of the implant and asked for a new clinical study of Probuphine’s effectiveness in treating opioid addiction.
Braeburn recently reported the results of a six month, double-blind clinical trial of Probuphine on 177 patients, which found that the implant was more effective than buprenorphine tablets in treating addiction. The company said the implant insertion and removal were "generally well tolerated," although nearly one in four patients had a "mild" adverse event at the implant site.
“The data from this trial are encouraging and underscore the benefit of longer term medical treatments for patients with opioid addiction. I am confident that the implant, if approved by FDA, will be at least as effective as a sublingual formulation and have the added benefits of reducing problems related to compliance, misuse and abuse," said Richard Rosenthal, MD, Professor of Psychiatry and Medical Director of Addiction Psychiatry at the Icahn School of Medicine at Mount Sinai.
Braeburn and Titan plan to resubmit a New Drug Application (NDA) for Probuphine to the FDA in the second half of this year.
Long Term Injection for Pain
Braeburn has formed another partnership with Camurus, a Swedish drug company, to develop an injectable buprenorphine drug to treat addiction and chronic pain -- a single injection that lasts as long as a month. Camurus has already completed successful Phase I and II studies on the drug and both companies hope to start a Phase III trial later this year -- with the goal of seeking regulatory approval in 2016.
“There have been many conversations with expert clinicians and they’ve told us that they think buprenorphine in general, in a non or less abuse-able form of buprenorphine, in either an implant or an injection could really be game changing,” said Sheldon. “It is part of our plan to move into pain because pain and opioid addiction are so interconnected and we think there are ways, by treating patients with a less abuse-able formulation, you could actually help alleviate the addiction problem.”
Sheldon admits a lot more work needs to be done before a buprenorphine implant or injection is available to treat chronic pain.
“We haven’t studied it yet in pain and we haven’t had any conversations yet with the FDA. So there’s a lot more to do to get to that point,” she said.
Another formulation of buprenorphine to treat pain may be coming to the market relatively soon. Endo International (NASDAQ: ENDP) and BioDelivery Sciences (NASDAQ: BDSI) have submitted a new drug application for a buprenorphine film patch to the FDA. The companies are hoping for FDA approval by October of this year.
Although the patch contains much smaller doses than buprenorphine tablets or patches already on the market, the companies say the film is very effective in treating pain because the drug is absorbed through the inside lining of the cheek and enters the blood stream faster.