The Court of appeal for Federal circuit (CAFC) has reversed a portion of a previously decided summary judgment on patent litigation between innovator Ortho-McNeil ( a subsidiary of Johnson & Johnson) and Caraco (subsidiary of Sun Pharma), Teva regarding Acetaminophen 325 mg + Tramadol Hydrochloride 35.5 mg tablets (Ultracet). Further, the court has remanded the litigation to a lower court for further proceedings.
Background of the case
Prior Art: 1) Kurt Flick et al patent US3652589 published in 1972, which disclosed Tramadol and it’s combination with other analgesics. The example 23 of Flick’s patent disclosed combination of Tramadol with Acetaminophen and two other drugs.
2) Also, a German publication “WHO cancer pain guidelines” suggested various combinations of analgesics for treatment of Cancer pain.
United States district court for the district of New Jersey’s decision
Innovator Ortho claimed the combination of Tramadol + Acetaminophen in US5336691. The patentability basis as per '691 was synergistic action of both analgesics. The Tramadol is centrally acting analgesics, whereas, Acetaminophen acts by inhibiting cyclooxygenase (COX) enzyme.
Innovator got final approval to market this product on Aug 15, 2001. Afterwards due to commercial success of Ultracet, some generic players like Barr and Kali labs filed ANDA with invalidation grounds against said patent.
The example 23 of Flick’s patent has disclosed ratio of 1:10 of Tramadol + Acetaminophen. The said ratio was being covered under the scope of Ortho’s patent. Also, a German publication “WHO cancer pain guidelines” suggested various combinations of analgesics during treatment of Cancer.
Innovator in a bid to protect the patent from invalidation, filed re-examination and reissue request with USPTO to amend the disputed claims. The innovator disclosed all the references cited against the patent by generic players to examiner. Also, innovator redrafted the claims to overcome obviousness challenge of generic players. Finally, examiner reissued the US5336691 as USRE39221 after some changes.
The said reissued patent (which is listed in orange book for Ultarcet) covers:
USRE39221 (Expiry: Aug 9, 2011): The reissued claims covered a pharmaceutical composition comprising a Tramadol material and Acetaminophen, wherein the ratio of the tramadol material to acetaminophen is about 1:5.
After reissue of ‘691 as RE’221, the innovator asserted claims of ‘221 against generic players like Barr and Kali Labs. The generic players in turn filed for Summary Judgment motion of invalidity and non-infringement.
On Aug 12, 2008, the United States district court for the district of New Jersey’s Judge D.M Cavanaugh issued a summary judgment opinion and invalidated the asserted claims 43-48, 51, 54, 67, 69, 72 and 74 of ‘221 patent as obvious in the light of prior art. Also, the court invalidated the claim 6 of ‘221 patent based on prior art and found the claim to be anticipated and obvious.
Court of appeal for Federal circuit Decision
The innovator Ortho appealed against the said decision in CAFC on Aug 25, 2008.
The court observed that claims 6, 43-48, 51, 54, 67, 69, 72 and 74 covers combination of Tramadol + Acetaminophen from about 1:5 to about 1:19. A single tablet containing these two important ingredients was not disclosed in prior art.
Further, during trial, court gave importance to innovator’s expert testimony. The expert opined that Filck’s reference couldn’t obviate the said combination. Also, the interaction between Tramadol and Acetaminophen was poorly understood in 1990. The expert further opined that Flick’s broad statement that Tramadol “often” displayed synergistic action in combination with other analgesics would not be enough to obviate Tramadol + Acetaminophen ratio of about 1:5 to about 1:19. Also, expert testified that German reference teaches away from selecting the claimed combination.
Finally, the court in a 2-1 decision (panel of Judges Mayer, Prost and Moore), has remanded the litigation to United States district court for the district of New Jersey for further proceedings. The court opined that the claims 43-48, 51, 54, 67, 69, 72 and 74 of ‘221 patent are not invalid due to obviousness. Also, court has opined that claim 6 of the disputed patent is invalid due to obviousness (and not due to anticipation).
Also, the fellow Judge H.R Mayer has written dissent against said decision. As per Judge Mayer, the ‘221 patent is not novel as the said patent covers combination of two well known analgesics Tramadol and Acetaminophen”
Opinion of CAFC Here
The generic players
Following generic players have final approval for this product:
1) Barr (ANDA approved on Jul 26, 2006)
2) Caraco (ANDA approved on Dec 16, 2005)
3) Kali Labs (ANDA approved on Apr 21, 2005)
4) Mylan (ANDA approved on Sep 26, 2008)
Earlier, Innovator has settled with generic player Kali Labs (a subsidiary of Par Pharma) in July, 2007. The Kali labs have licensing agreement with innovator.
The revival of this case will certainly help innovator in blocking other generic players
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