McElroy FTO – My Bad

by bobbydiggs

McElroy US Patent Should Not Cause a Freedom-To-Operate (FTO) Problem for Vivus’ Qsymia

McElroy Is Still a Major Unresolved Prior Art Issue for Qsymia Patent Estate

In Part 2 of my July 20, 2012 blog entry, “More Freedom-to-Operate Challenges for Qsymia”, I wrote about U.S. Patent No. 6,323,236, which lists Susan McElroy as sole inventor and the University of Cincinnati as assignee (“McElroy Patent”).  In that piece I made a series of arguments for why this patent presents freedom-to-operate challenges to Vivus’ recently approved drug Qsymia.

Upon further reflection I no longer believe that Qsymia (if sold with its current FDA-approved package insert) will infringe the McElroy Patent.  This patent claims priority to U.S. Provisional Patent Application No. 60/121,339, filed Feb. 24, 1999.  Claim 10 in the original filing of this earlier provisional patent application reads:

 “10. The method of claim 1 wherein the Impulse Control Disorder is an overweight/obesity condition and the compound is used in conjunction with one or more other drug compounds selected from the group consisting of sibutramine, psychostimulants, and orlistat.”

Original Claim 10 provides clear support for an overweight/obesity condition being a type of Impulse Control Disorder that is treated as part of the invention.  What I didn’t appreciate when I wrote the July 20, 2012 blog entry was that this support never appears in the final issued McElroy patent, and the earlier filed provisional application does not appear to be incorporated by reference in the issued patent.  In any event, the Impulse Control Disorders as claimed in the issued McElroy Patent are limited by to (see claim 1 of U.S. Patent No. 6,323,236):

 “the group consisting of intermittent explosive disorder (ED), kleptomania, pathological gambling, pyromania, trichotillomania, compulsive buying or shopping, repetitive self-mutilation, nonparaphilic sexual addictions, severe nail biting, compulsive skin picking, personality disorders with impulsive features, attention deficit/hyperactivity disorder, Binge Eating Disorder, bulimia nervosa, anorexia nervosa with binge eating and substance use disorders.”

While there are other independent claims in the issued McElroy patent, the list of Impulse Control Disorders is limited to the same list as in claim 1 or a subset of that list.  There is plenty of support in the McElroy patent for the combination of topiramate and phentermine and its use for treating an “overweight/obesity condition”, however, there does not appear to me to be sufficient support for arguing that an “overweight/obesity condition” is a subset of any of the Impulse Control Disorders listed in Claim 1 of the issued McElroy patent. While claim 8 makes reference to treating “eating disorders” as I outlined in the Part 2 of the original blog, what I now fully appreciate is that there is not a specific definition of “eating disorders” in the McElroy patent that embraces overeating, overweight, obesity or even McElroy’s somewhat odd term, “overweight/obesity condition.”  Furthermore the standard dictionary definition of “eating disorder” doesn’t seem to encompass such conditions either.

Therefore, I no longer think that Qsymia being sold for weight loss would infringe the McElroy patent.  If Vivus were to do further clinical trials and have the label amended to include one or more of the disorders listed in Claim 1, then Vivus’ Qsymia might run afoul of the McElroy patent, or Vivus might want to take a license to McElroy.  However, with a large market like weight loss, Vivus should not be overly constricted by freedom-to-operate concerns regarding McElroy.  Treating only obesity is a very commercially attractive position.

So let’s recap: 1) McElroy discloses a combination of topiramate with a psychostimulant defined to include phentermine, before Dr. Najarian earliest patent filing discloses a combination topiramate and phentermine.  2) McElroy discloses the use of a small list of drugs that includes phentermine to be combined with topiramate for the treatment of “overweight/obesity condition” before the earliest Qsymia patent describes using a combination of phentermine and topiramate to treat obesity or cause weight loss.  3) The issued McElroy patent fails to claim either the composition of matter in 1) or the method of treatment in 2); University of Cincinnati appears to have dropped the ball on this one.  4) The University of Cincinnati does not appear to be in a position to go back and get these claims because they appear to have failed to file any kind of continuing application prior to the issuance of the original US McElroy patent and the deadline for filing a broadening reissue application under 35 USC 251 (two years from the original issuance of the McElroy patent) has expired long ago.

The set of circumstance provided above in 1-4 may mean that Dr. Najarian would not need to establish that he invented Qsymia prior to Dr. McElroy’s invention of a topiramate/phentermine combination, but rather Dr. Najarian and Vivus probably only need to show that Dr. Najarian made his Qsymia invention earlier than McElroy’s earliest filing date of February 17, 1999 to eliminate McElroy as prior art in the US.

Can Vivus and Dr. Najarian make such an evidentiary showing?  I don’t see anything in the public record that answers this question.  If the answer is no, then McElroy is still potentially devastating prior art for the Qsymia patents in the US and regardless of the answer the McElroy patent is a major prior art problem in Europe where the seminal issue is who filed first, not the invention date.  In a future blog, I will provide more color on the issue of the McElroy patent’s strength as prior art against Vivus’ Qsymia patents in Europe.

For the record I am only withdrawing my position on freedom-to-operate with regard to McElroy and slightly modifying my position on the prior art impact the McElroy patent will have on the Qsymia patent estate in the US.  I stand by the rest of the analysis in my earlier blogs and continue to have a great deal of doubt as to the strength of Vivus’ over-all patent position on Qsymia.