Prodrug Resources

Alkermes Prodrug for Treatment of Multiple Sclerosis: NCE?

The Food and Drug Administration (FDA) began requiring drug efficacy, in addition to safety, for approval in 1962 based on the Kefauver-Harris Amendment. Despite this requirement, many drugs that have been approved by FDA have limited efficacy (eg, drugs that treat cancer or Alzheimer’s disease). In many cases, some portion of the limited efficacy is […]
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505(b)(2) Prodrug Fails Phase III Study

Development of drugs for new indications entails more risk of failure than simply changing formulations.  Just ask XenoPort, which announced May 19th that its prodrug of R-baclofen, arbaclofen placarbil,   failed to show efficacy in a Phase III clinical trial. Arbaclofen placarbil was being studied for multiple sclerosis-related spasticity. Racemic baclofen,  now generic, is indicated for treating muscle […]
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Non-clinical bridging – Most 505(b)(2)’s Don’t Require Full Tox Package

I have just finished a webinar under the sponsorship of the DIA dealing with non-clinical bridging. In this post, I’d like to share one of the case studies from my presentation to illustrate what should be considered during development. The example is the development of gabapentin enacarbil by XenoPort/GSK for restless leg syndrome. Gabapentin enacarbil […]
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2010 505(b)(2) Approvals

We join everyone else this time of year and develop a list – ours is a list of FDA approvals made under 505(b)(2). As widely reported (WSJ article here) FDA reported that approvals were down in 2010. Frankly, it’s hard to tell what the figures are, let alone mean. The Agency sometimes includes approval of […]
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Pro-Drug Denied

I am frequently asked if 505(b)(2) projects fail or whether any NDA submissions are rejected. My answer is that the vast majority succeeds and are eventually approved. Those that fail more often are due to money or design issues, not execution risks. Today I discuss an example of a failure based, in large part, on […]
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FDA’s Determination of Vyvanse as NME Upheld

On March 4, 2010 the U.S. District Court for the District of Columbia agreed that FDA was within its rights to grant Shire’s Vyvanse (lisdexamfetamine dimesylate) NME status and thus, 5-years exclusivity. New Rivers Pharmaceuticals (NRP) was the original sponsor of the lisdexamfetamine NDA. During the 2/23/2007 approval, FDA determined that the API was a new molecular […]
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Did FDA Make a Mistake? Prodrug Emend Exclusivity Reconsidered

It is important to give the FDA credit for admitting mistakes. Yesterday’s posting in this blog concerned Vyvance’s NCE and 5 year exclusivity status. The thorough response by the FDA to the Actavis request for reconsideration of the new chemical entity (NCE) 5 year exclusivity granted to Vyvanse (lisdexamfetamine dimesylate) Capsules, the prodrug of dexamphetamine, […]
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FDA Reaffirms 5-year Exclusivity for a Pro-drug

FDA has reaffirmed its prior assignment of 5 years exclusivity to Vyvance (lisdexamfetamine dimesylate).  When Vyvance was approved in 2007, this prodrug of dextramphetamine was given NCE status with a 5 year exclusivity.  With this exclusivity, the FDA may not accept an ANDA before the exclusivity expires unless a paragraph IV is filed, in which […]
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505(b)(2) Combination Meets Phase 3 Goals

Horizon Therapeutics announced yesterday that its “fixed-dose combination product containing ibuprofen and famotidine, demonstrated a statistically significant reduction in the incidence of non-steroidal anti-inflammatory drug (NSAID)-induced upper gastrointestinal (gastric and/or duodenal) ulcers in patients with mild-to-moderate pain when compared to ibuprofen alone.”  Note that the drug development program contained two Phase 3 trials, one examining gastric […]
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Creating a safer NSAID

Many companies are attempting to reduce the GI bleeding, ulcers and perforations caused by administration of NSAIDS (e.g., ibuprofen, naproxen, aspirin).  Since Vioxx was removed from the market (and it was a safer NSAID with respect to GI), there has been an surge of NSAID activity around these existing actives.  We understand that the FDA’s […]
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Fospropofol turned down or approved by FDA Advisory Committee?

MGI Pharma’s Aquavan(R) (fospropofol) is a phosphate prodrug of the anesthetic propofol.  Propofol  must be administered by an anesthesiologist because of its rapid onset. The phosphate prodrug’s time to onset is delayed due to the conversion to the active moiety.   A slow onset of sedation would reduce the likelihood of sudden and unexpected general anesthesia.  […]
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