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Does the Lotus IPR matter to Celgene’s Revlimid or the Bristol transaction?

Zachary Silbersher

We previously blogged about Dr. Reddy’s IPRs filed against MDS patents covering Celgene’s Revlimid®.  Those IPRs attracted considerable attention because they were, for better or worse, one of the few data-points within the Revlimid® patent skirmishes we are guaranteed to see before the Bristol transaction closes.  The Lotus IPR attacking one of Celgene’s multiple myeloma patent is another datapoint.  The PTAB’s decision on whether to institute the IPR is due March 18.  How much does Lotus IPR really matter?

Alvogen’s and Lotus’ petition for inter partes review (IPR) challenges U.S. Patent No. 7,968,569.  The patent is directed to using lenalidomide to treat multiple myeloma.  Yet, the patent also covers a dosing regime for doing so – administering lenalidomide over a 28 day cycle with a seven day rest period in combination with dexamethasone. 

During prosecution of the patent, the feature that eventually permitted its allowance was not administering the drug to treat multiple myeloma, or the coadministration with dexamethasone.  Rather, it was the 28 day treatment cycle, with a seven day rest period.  Sure enough, this feature forms the focus of Celgene’s response to Lotus’ IPR. While Celgene quibbles with many points within Lotus’ IPR petition, the bulk of Celgene’s response—and, likely the key feature that the PTAB will wrestle with—is whether the prior art sufficiently taught the 28/7 treatment cycle. 

On the merits, Celgene mounts an aggressive attack against Lotus’ IPR on this point.  Celgene strenuously argues that, despite proffering multiple pieces of prior art, none of them show the same 28/7 treatment cycle as required by the claims of its patents.  Rather, they show shorter treatment cycles, and longer rest periods, or other variations from that dosing cycle required by the patent.  On the basis of those arguments, Celgene has a non-negligible chance of defeating institution of Lotus’ IPR.

On the other hand, Lotus has made a tractable case that treatment cycles were well-known in the art for administration of cancer drugs. And rest periods were equally well-known, especially for drugs with potential toxicities.  And while Celgene hammers home the fact that the prior art has not taught the precise 28/7 cycle recited in its patent, Celgene’s response to Lotus’ IPR is short on selling its particular invention.  In other words, Celgene has not necessarily demonstrated why its claimed 28/7 treatment cycle was especially novel—because of unexpected results, superior results or whatever.  While that is not technically necessary for patent owner to defeat an IPR, it typically helps at the institution stage.

Putting aside the merits, will Lotus’ IPR meet the same fate as Dr. Reddy’s?  Dr. Reddy’s IPRs were defeated by a technical issue—the PTAB found that it Dr. Reddy’s had failed to sufficiently show that two of its primary prior art references (namely, Celgene press releases) were actually published on the date Dr. Reddy’s claimed them to be.

 That issue does not infect Lotus’ IPR.  While Lotus also relies upon press releases as primary prior art references, Celgene has not affirmatively contested those press releases are not prior art.  And even so, it would be less terminal for Lotus because one of Lotus’ lines of attack in its IPR does not rely upon the press releases whatsoever.  So, we are unlikely to see a repeat of the Dr. Reddy’s institution defeats.

If the Bristol transaction were not looming, the Lotus IPR would not likely be terribly material to assessing the expected entry of a generic for Revlimid®.  Celgene has several multiple myeloma patents that it has asserted against the generics.  For whatever reason, Lotus attacked only one of those patents.  Regardless of whether ‘569 patent falls, Celgene has other MM patents with the same or similar expiration dates ready to do the same job.  Those patents have already been asserted against the other generics. 

If Lotus prevails in the IPR, that decision may read through in the District Court cases to the validity of the other multiple myeloma patents.  Yet, that read-through would not be automatically self-enforcing.  In other words, Lotus would still have to go through the litigation mechanics of proving those other patents invalid—either through summary judgment or trial.  That alone takes time. 

Is the Lotus IPR an adequate measure of whether Bristol did its diligence with respect to its anticipated acquisition of Celgene?  Reviewing the Revlimid® patent landscape, there are many things to discuss—the IPRs, the REMS patents, the different generics, the interplay between the MDS and multiple myeloma patents. 

Despite all of this, the fact remains that the most important issue that will likely move the needle, and drive settlement, is resolution of the polymorph patents.  Whether Dr. Reddy’s amorphous argument will prevail remains the biggest known unknown regarding when we will likely see generic Revlimid®. 

Dr. Reddy’s could have scored a minor coup by knocking out the MDS patents, pursuing entry on that indication alone, and relying on inadvertent and unintentional off-label prescriptions.  Alternatively, had Dr. Reddy’s lost those IPRs on the merits—rather than on a technical argument—that would have had more read-through in the district court litigations. But Dr. Reddy’s technical deficiency in the IPRs can be fixed before it can make the same argument in court.

And Dr. Reddy’s might still re-file those IPRs, since those IPRs could still theoretically be re-filed to correct the technical deficiency regarding the prior art.  There is theoretically still time.  Even still, Dr. Reddy’s would still have to contend with the polymorph patents.  And that brings us back to the pending district court cases.