United And Divided: Natco's Patent Challenge On Revlimid Leads Dr. Reddy's To Up Its Pitch

MUMBAI - Natco Pharma's patent challenge earlier this month over Celgene's blockbuster multiple myeloma drug Revlimid (lenalidomide) has led India's Dr. Reddy's Labs to fast-track its own development of the product, which was brought under a restricted distribution plan by U.S. FDA due to its risky profile.

"We are trying to procure samples to do our product development for the U.S. market," a Dr. Reddy's spokesperson wrote in response to queries on the next strategy following Natco's patent challenge.

"We have sent a controlled correspondence to the FDA informing of the status of the samples and to help us with procuring the samples. We are awaiting direction from FDA," the Dr. Reddy's spokesperson said.

Natco Sails Through, Dr. Reddy's Stuck With REMS

Last June, having failed to procure samples of Revlimid from Celgene or distribution channels to conduct its bioequivalence studies, Dr. Reddy's had urged FDA through a citizen petition to use provisions of the FDA Amendments of Act of 2007 to prevent REMS from blocking ANDA applications (Also see "Will REMS Delay Generics? Dr. Reddy’s Revlimid Petition May Help Determine Answer" - Scrip, 24 Jun, 2009.).

While Dr. Reddy's engaged in protracted discussions with FDA to streamline the sample procurement process over the last few months, Natco's recent application raised questions among a few analysts on the bioequivalence tests that have been conducted by Natco.

To date, Natco maintains that it has satisfactorily complied with existing regulations required for testing its product with the reference drug.

Natco claimed first-to-file status for the 25 mg strength but it has filed applications for all 5 mg, 10 mg, 15, mg and 25 mg dosages of Revlimid. If Natco prevails over Celgene's court defenses, it may stand entitled to six months of marketing exclusivity in the U.S. (Also see "India's Natco Eyes Generic For Celgene's Mega Brand Revlimid; Will REMS Scuttle The Move?" - Scrip, 1 Sep, 2010.).

Natco And Dr. Reddy's Have A Deal

Interestingly, last April Dr. Reddy's and Natco - both headquartered in the central Indian city of Hyderabad - struck a deal to develop, manufacture and supply a range of undisclosed oral and injectable oncology drugs targeted at the U.S. market (Also see "India’s Dr. Reddy’s, Natco Strike Deal To Target Abraxane And Several Other Oncology Drugs" - Scrip, 16 Apr, 2009.).

The only compound that was mentioned as a potential target was nanoparticle albumin-bound paclitaxel, which by default is now also owned by Celgene following its acquisition of Abraxis Bioscience earlier this year.

As part of the deal, a profit-sharing mechanism was put in place and regional commercialization rights were divided for specific compounds.

It is still not clear if Natco and Dr. Reddy's have joint development plans for Revlimid, particularly because Natco has not disclosed its larger generic partner that has agreed to share litigation costs in the eventuality that Celgene sues the Indian company on charges of patent infringement. Natco, meanwhile, has expressed willingness to reach an out-of-court settlement, depending on Celgene's stance on the product.

Celgene's Revlimid clocks global sales of $2.5 billion, of which U.S. sales have contributed $1.3 billion annually and continue to grow more than 40 percent, according to IMS Health. A derivative of Thalomid (thalidomide), lenalidomide has evoked concerns associated with birth defects among other side effects, and therefore the marketing and prescription of the product are monitored closely by regulatory agencies as well as the company.

- Vikas Dandekar ([email protected])