Oxycodone - USA

On Sep 28, 2018, District of Massachusetts granted summary judgment of non-infringement for 2 patents & denied with respect to one patent.

Plaintiffs Purdue brought suit against Collegium Pharmaceutical, Inc. for infringement of three patents U.S. Patent Nos. 9,073,933 (“the ’933 patent”), 8,652,497 (“the ’497 patent”), and 9,155,717 (“the ’717 patent”). The infringement claims arise out of Collegium’s filing of a New Drug Application (“NDA”) for its abuse-deterrent, extended-release oxycodone products, XTAMPZA ER. Collegium moved for summary judgment on three grounds. First, it maintains that the ’933 patent is invalid under a theory of issue preclusion, or collateral estoppel. That contention is based on a judgment from the Southern District of New York, affirmed by the Federal Circuit, that three related patents (low-ABUK) owned by Purdue are invalid. Second, Collegium asserts that even if the ’933 patent is valid, it is entitled to judgment of non-infringement as a matter of law because it is not literally infringing and oxycodone myristate (the active ingredient in its product) is not the equivalent of oxycodone hydrochloride (the active ingredient in Purdue’s product). Third, it argues that summary judgment of non-infringement of the ’497 and ’717 patents is appropriate because those patents claim the addition of an “irritant,” and its product does not contain an “irritant.”

The ’933 patent is entitled “Oxycodone Hydrochloride Having Less Than 25 PPM 14- Hydroxycodeinone (impurity).” The ’497 & ‘717 patents are entitled “Pharmaceutical Formulation Containing Irritant.” Before this litigation, in 2016, the Federal Circuit affirmed Judge Stein’s determination that the asserted claims of the low-ABUK patents were obvious in light of the prior art in Teva case. Then after that in another action, Mylan moved to dismiss the complaint for infringement of ‘933 on the basis of collateral estoppel (that is, issue preclusion) in light of Judge Stein’s decision in Teva. Magistrate Judge Sherry R. Fallon issued a report and recommendation to the district judge recommending that the motion to dismiss be denied. Magistrate Judge Fallon concluded that “defendants have failed to establish that the invalid claims of the previously-litigated low-ABUK patents are sufficiently identical to the disputed claims of the ’933 patent.”

Collegium developed an abuse-deterrent, ER formulation of oxycodone called XTAMPZA ER. XTAMPZA ER uses a microsphere-incapsule platform and was “designed to protect the active pharmaceutical ingredient from immediate release upon attempted manipulation of the formulation.” The microspheres contain myristic acid, yellow beeswax, carnauba wax, stearoyl polyoxyl-32 glycerides, and oxycodone API. Collegium appears to contend that the drug substance present in XTAMPZA ER is oxycodone base; Purdue disputes that fact, contending that oxycodone is present in XTAMPZA ER as oxycodone myristate salt.

Issue preclusion:

Purdue asserted three independent claims from the ’933 patent: claims 1, 10, and 16. Relying on Teva, which found the asserted claims of the low-ABUK patents invalid, Collegium argued that the ’933 patent claims are invalid under a theory of issue preclusion. However, Court took a similar approach as in Mylan, and denied the motion for summary judgment. Specifically when Judge considered the low-ABUK patent claims, he determined that “the 8α-derived limitation of the asserted product claims [would be] disregarded as a process limitation” that was immaterial to obviousness. Thus The Teva court thus only actually adjudicated the validity of the patents claiming “low-ABUK oxycodone API product.” Collegium contends that despite the surface differences between the product claims in this case and the prior litigation, issue preclusion should apply because those differences do not materially alter the validity analysis. Court, however said that under the circumstances, the step of “removing 8α” may materially affect the ’933 patent’s validity analysis. See Graham v. John Deere Co., 383 U.S. 1, 17–18 (1966) (listing factors of obviousness analysis). At the very least, viewing the facts in the light most favorable to the non-moving party, Purdue has raised a disputed issue of material fact as to this point. Accordingly, Collegium will not be granted judgment as a matter of law on the basis of issue preclusion.

Non-infringement of ’933 patent:

Collegium also contends that it is entitled to summary judgment of non-infringement on the ’933 patent. Collegium maintains that the doctrine of prosecution history estoppel and the Federal Circuit’s opinion in Wm. Wrigley Jr. Co. v. Cadbury Adams USA LLC, 683 F.3d 1356 (Fed. Cir. 2012), preclude Purdue as a matter of law from claiming that oxycodone myristate is the equivalent of oxycodone hydrochloride. Collegium further contends that XTAMPZA ER does not infringe under the doctrine of equivalents because oxycodone myristate does not perform the same function as oxycodone hydrochloride. Collegium first contends that Purdue’s claim is barred by the doctrine of prosecution history estoppel. It contends that during prosecution of the application that would become the ’072 patent, “Purdue specifically distinguished the [hydrochloride] form of oxycodone over other forms of oxycodone.” According to Collegium, having made that distinction to overcome a PTO rejection, Purdue thereby disclaimed all forms of oxycodone other than oxycodone hydrochloride. Court held that Based on that language, Purdue may well have disclaimed products including oxycodone free base during prosecution. But it does not follow that Purdue necessarily surrendered all forms of oxycodone other than oxycodone hydrochloride. At a minimum, Purdue’s response to the examiner did not clearly disclaim all other forms of oxycodone, including oxycodone myristate.

With respect to Function-Way-Result analysis, Collegium argued that myristic acid functions “to lock oxycodone up in wax so that it is not accessible to an abuser.” Based on that evidence, Collegium asks the Court to find that “myristic acid . . . functions to solubilize oxycodone in the wax matrix and hydrochloric acid . . . functions to make oxycodone bioavailable,” and are therefore not equivalents. Purdue, on the other hand, maintained that the correct comparison for the function-way-result test does not involve myristic acid at all. Purdue argued that “the claim element that is literally missing from [XTAMPZA ER], and for which the doctrine of equivalents is relevant, is oxycodone hydrochloride, not ‘hydrochloride.’ The equivalent element is oxycodone myristate, not myristic acid.” Court said that Collegium has provided insufficient evidence as to the function of oxycodone myristate— as opposed to myristic acid—to refute Purdue’s theory. It appears that Purdue has presented a genuine issue of disputed material fact as to whether oxycodone myristate performs substantially the same function as oxycodone hydrochloride, and that accordingly summary judgment is inappropriate.

Non-infringement of ’497 and’717 patents:

Finally, Collegium argued that it is entitled to summary judgment of non-infringement of the ’497 patent and the ’717 patent because the myristic acid used in XTAMPZA ER is not an “irritant.” The resolution of that issue turns on the Court’s previous construction of the term “irritant.” As noted, Collegium uses myristic acid in XTAMPZA ER to dissolve oxycodone base in wax. Although Purdue does not dispute that myristic acid has such a purpose, it contends that myristic acid was also included in XTAMPZA ER to act as “an abuse-deterring irritant.” According to Purdue, the molar ratio of myristic acid to oxycodone base in XTAMPZA ER is 6:1. This, Purdue contends, is evidence that the extra myristic acid functions solely as an irritant. Collegium contends that all of the myristic acid is necessary to solubilize oxycodone and drive salt formation. Its NDA for XTAMPZA ER specifically states that excess myristic acid is necessary to ensure that enough oxycodone myristate is formed and to reduce the concentration of free oxycodone base. With respect to the abuse-potential studies, Collegium explains that its NDA stated that irritation after snorting was “likely caused by particle size and lack of solubility of the wax microspheres.” Collegium also denies that myristic acid was included for any purpose other than solubilizing oxycodone in the wax matrix.

Court siding with Collegium said that it had put forth evidence that “excess myristic acid” is in fact an excipient that performs a necessary function and not act as an irritant. Purdue has not rebutted that evidence with anything other than speculation and argument. Again, Purdue claimed a composition with a separate “irritant” component. It does not (and likely could not) claim every composition that happened to have an irritating quality under some set of circumstances, whether or not the irritant was a separate component. Accordingly, and under the circumstances, the Court will grant summary judgment as to non-infringement of the’497 and ’717 patents.

CONCLUSION: The motion for summary judgment of Collegium Pharmaceutical, Inc. is GRANTED in part and DENIED in part. Specifically, summary judgment is granted to defendant on all claims of US 8,652,497; 9,155,717 and denied with respect to US 9,073,933.