A fellow patent attorney (who wishes to remain anonymous) called my attention to a recent decision issued by Judge Sue L. Robinson of the Delaware District Court.  Cancer Research Technology et al. v Barr Laboratories et al., D-Del, Civ. No. 07-457-SLR, January 26, 2010.  Download CRT v Barr.

I’m not a district court decision junkie: since most patent cases revolve, at least in part, around claim construction, and since under Cybor the Federal Circuit reviews claim construction de novo, I tend to ignore many district court decisions – why bother getting into a claim construction-based case before the Federal Circuit has had its say on claim construction?  This case, however, Cancer Research Technology, et al. v Barr Laboraties et al. (really Schering v Barr) dealt with the question of prosecution history laches and inequitable conduct.  The i.c. part is primarily of interest to people practicing in the pharma and biotech fields, where patent applications are usually filed before extensive laboratory and clinical testing of compounds has been carried out.  The laches part is of greater general interest, although less so under the 20-years-from-filing regime.

At issue was US 5,260,291, directed to tetrazine derivatives and their use in treating various cancers.  The patent covers the compound temozolomide, which Schering markets under the name Temodar® for the treatment of two types of brain cancers, glioblastoma multiforme and refractory anaplastic astrocytoma.  As explained in the ruling, the story started in the early 1980’s, when some researchers at Alston University in England developed some tetrazine derivatives and, in conjunction with UK pharmaceutical company May & Baker, began testing these for use against various cancers.  A priority application was filed in England in 1981; a US application, 06/410656, claiming priority to the UK application was filed in 1982.

A first OA was mailed November 18, 1983, in which the Examiner rejected the application for lack of utility, asserting (on the basis of an MPEP section that has long since been supplanted) that it was necessary for the application to include data showing efficacy of the compounds in humans, but that the application lacked such data.  Rather than file a substantive response, the applicants filed a continuation on March 6, 1984 and let the parent case go abandoned.  In October 1984 the same examiner made the same rejection against the continuation application, and again, the applicants didn’t respond, but instead filed another continuation and let the parent case go abandoned.

Although at various points in time the representatives before the USPTO changed, this pattern of rejection-for-lack-of-utility followed by non-response-file-a-continuation repeated itself.  Again.

And again.

And again.

And again.

All in all, over the course of ten years, the applicant filed ten continuations before it filed a substantive response to the lack-of-utility rejection, in February 1993.  And what was the substance of that substantive response?  That according to a 1986 BPAI decision, Ex Parte Krepelka, the applicants didn’t need to provide data showing efficacy in humans, and the animal test data already present in the application was sufficient.  In response, the examiner mailed a Notice of Allowability, and pointed to a 1987 journal article by one of the inventors that showed that some of the compounds were active against tumors in mice as further evidence of utility.

The ‘291 patent issued in November 1993, 11 years after the first application in the chain had originally been filed, entitled to 17 years of term from grant.  It then lay dormant until 2007, when Barr filed an ANDA and CRT/Schering sued.

At trial Barr stipulated to infringement of the asserted claims, but argued that the patent should be unenforceable due to prosecution history laches, i.e. unreasonable delay in prosecution by the applicants.  Judge Robinson accepted this argument, in the process rejecting CRT’s assertion that it hadn’t substantively responded because the examiners required human trial data, which was unavailable.  Judge Robinson ruled that not only was there no explanation given for the delay, but that the response actually filed in 1993 was based on a 1986 BPAI decision which itself invoked a 1969 CCPA decision.  Thus much earlier in prosecution, the applicants could have presented plausible arguments asserting that human test data was unnecessary, and at least made a reasonable attempt to advance prosecution of the case.  From the evidence adduced at trial, the only reason apparent to Judge Robinson for the prolonged delay was to enable CRT to find a strategic partner with which to commercialize the invention.  That was not a good enough reason.  Thus, said the Judge, the patent is unenforceable for prosecution laches.

The groundbreaking part of the decision dealt with the question of intervening rights.  In previous cases of prosecution laches, the defendants had relied on the long delay in prosecution – at a time when US patent applications were kept secret until they actually issued – to develop a business; in the words of the case law, the defendants had “intervening rights”.  CRT/Schering argued that Barr (nor anyone else) had developed such intervening rights here, and therefore Barr was not entitled to the relief sought.  Judge Robinson disagreed: the seminal CAFC cases dealing with prosecution laches, the 2002 and 2005 Symbol Technologies v Lemelson cases, did not impose a requirement for intervening rights to exist in order for a patentee to be guilty of prosecution laches.  Put differently, laches is wholly dependent on the applicant, and has nothing to do with whether or not third parties are in fact adversely affected by the applicant’s delaying tactics.

If upheld on appeal, this aspect of the decision could have adverse effects for parties with patents that issued on pre-June 1995 applications and that are thus still in force.  In principle it could also affect patents filed after June 1995, although presumably the fact that it was known to the applicants that those patents would be subject to a 20-years-from-earliest-filing term induced them to avoid delaying the grant of their patents.

With regard to inequitable conduct, the decision doesn’t break new ground, but it does serve as a reminder to practitioners in the life sciences to be in touch with the inventors through prosecution and continually remind them of their duty to disclose relevant information – and not necessarily just prior art.  The issue here was that the application specifically identified and claimed about a dozen compounds as being “particularly active” against lymphomas and leukemia, and described those compounds as being “important individual compounds” of the disclosed genus, and even describing three of them as being “of particular importance”.

The rub was that research by at least one of the inventors in the late 1980’s, while the application was still being kept alive at the USPTO, showed that, in fact, some of those compounds weren’t active.  Such inactivity per se wouldn’t have been fatal, had the applicants then scaled back the scope of the claims to cover only the active compounds.  But they didn’t: they pressed on with the broad claims and claims on the now-known-to-be-inactive compounds.  Which meant that the data showing inactivity was highly material to patentability: when an examiner says your claims lack utility, and you have data that shows he’s right, that data is going to be of interest to him.

Turning to the second prong of the inquiry, intent to deceive the USPTO, Judge Robinson inferred this on the part of the inventor on the basis of the fact that during prosecution of the patent he had published more than 40 papers on tetrazine derivatives, including papers showing the inactivity of some of the compounds, yet didn’t see fit to provide this information directly the USPTO.  She also noted that one of the attorneys involved in prosecuting the case testified that he would have explained to the inventors their duty to disclose, and that in any event the inventor had signed a declaration stating that he was aware of the disclosure requirement.

Having found both high materiality and intent, the finding of i.e. was inevitable.  Whether or not this part of the decision will hold up on appeal will hinge in no small part on the CAFC judges assigned to the case.  Reading the district court decision, it’s not clear that the inventor intended to deceive the USPTO.  There were several changes of attorneys during the long prosecution of the ‘291 patent, both in the U.S. and in England, and it seems likely that the inventor may not have know that patent prosecution was ongoing and even if he did, that he didn’t realize he had a duty to disclose the negative test results to the USPTO.

Irrespective of how the CAFC holds on the inequitable conduct question, it’s clear that practitioners need to stay in contact with the inventors during prosecution, advising them that if newly-gathered data impacts the patentability of the pending claims (e.g. shows that the claimed invention lacks utility, at least across its full breadth), that information may need to be reported to the USPTO.  Then again, more often than not, negative data developed along the way leads to an abandonment of the application or diminution of the scope of the claims, so not it’s not clear that facts analogous to those of the present case will repeat themselves anytime soon.

Today’s post is by Guest Barista Daniel J. Feigelson in Israel and was first published in his America-Israel Patent Blog.

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