Orange Book Aficionados: Do Not Neglect Patent Listings for the Discontinued Strengths of Your Marketed Drugs
Just a little reminder that drugs with a marketing status of “Discontinued” in the FDA’s Orange Book should have up-to-date patent listings. Patent listings for discontinued strengths are especially important when there are strengths of the drug that are still being marketed. Without listed patents, an ANDA approval (if the strengths were not discontinued for safety or efficacy reasons) or a 505(b)(2) approval could occur without warning based on a Paragraph I or a “no relevant patents” certification.
When I was testing new code to add patent submission dates to my I discovered that Sun Pharmaceuticals’ XIMINO (minocycline HCl) had marketed strengths with listed patents and discontinued strengths without any listed patents. XIMINO was originally approved under 505(b)(2) with five equally spaced strengths: A-E. Later the two intermediate strengths, B and D, were discontinued. Seven patents are now listed for strengths A, C and E, but no patents are listed for intermediate strengths, B and D. The claims of five of those listed patents are methods that are not dependent upon the strength of the dosage form. After studying the patent claims and the XIMINO label, I did not see anything obvious that would preclude the five method patents from covering the two discontinued strengths.
Of course, I am not privy to the interactions between XIMINO's prior NDA holder, Ranbaxy, and the reference drug sponsor, Medicis. The patents listed for the marketed strengths of XIMINO do belong to Medicis. However, out of curiosity, I wrote code to see if I could find other instances in the FDA's current raw Orange Book data of NDAs in which marketed strengths of a drug have patents listed, but one or more discontinued strengths of the same drug do not. I found over . While some might be easily explained (a new, patented formulation of the drug replaced an original unpatented formulation), others might not. If one of these examples belongs to your company, you may want to determine if a patent submission for the discontinued strength would be appropriate.