Ivermectin - USA

On Jan 29, 2020, Federal Circuit reversed & remanded district court’s decision of patent invalidity based on inherent anticipation.

Galderma is NDA holder for Soolantra®, a topical pharmaceutical formulation containing 1% ivermectin. It is indicated for the treatment of inflammatory lesions of rosacea, a skin disorder characterized by facial flushing and redness. Teva on Dec. 30, 2016 filed ANDA with FDA seeking to market generic version. Galderma sued Teva for infringement and asserted claim 12 of the 9,089,587 patent; claims 2, 3, and 6 of the 9,233,117 patent; and claims 6, 7, 10, and 11 of the 9,233,118 patent. The asserted claims recite methods of treating inflammatory lesions of rosacea through topical administration of 1% ivermectin once daily to patients with inflammatory lesions of rosacea. The claims also recite certain efficacy parameters resulting from the treatment methods.

Teva asserted that the claims at issue were invalid as anticipated by U.S. Patent No. 5,952,372 (“McDaniel”) or U.S. Patent No. 7,550,440 (“Manetta”). District court after trial issued opinion in favour of Teva & found asserted claims invalid under anticipation. The district court found that McDaniel expressly discloses: methods for treatment of rosacea, including inflammatory lesions; a topical formulation containing about 1–5% ivermectin; and, once-daily application of ivermectin. It also found that McDaniel inherently disclosed the claimed efficacy limitations. This finding of inherency was based on the parties’ stipulation that “Manetta enables McDaniel in 2012 as to the formulation.” According to district court POSA would have been able to practice McDaniel’s disclosed treatment method with Manetta’s formulation (Soolantra formulation) without undue experimentation.” Because court found all asserted claims invalid for anticipation, it did not reach Teva’s arguments concerning obviousness and lack of written description. 

         

On Sep. 6, 2019, Galderma timely filed a notice of appeal. On appeal, Galderma specifically challenged district court’s (1) use of multiple references for its anticipation analysis; and (2) finding of inherency based on “a mere possibility.”

1. Reliance on Multiple References -

Galderma argued that the district court erred by finding the asserted claims anticipated based on disclosures found in two references, in contravention of settled law that anticipation must be based on disclosure in a single reference. According to Galderma, although the district court was permitted to look to other references to interpret the allegedly anticipatory reference, it was strictly prohibited from using additional references “for a very specific teaching.” Particularly, Galderma argued that the district court erred by relying on second reference, Manetta for its teaching of the Soolantra formulation.  Galderma further argued that the district court confused enablement with anticipatory disclosure as Manetta’s enablement of McDaniel’s formulation only means that a POSA could practice the general formulations disclosed in McDaniel. It cannot mean that McDaniel discloses the specific formulation disclosed in Manetta.

Teva argued that the district court’s findings are consistent with precedent. It argued that disclosure of a genus (here, McDaniel’s disclosure of a 1–5% ivermectin formulation) can anticipate a claimed species if a POSA would discern or possess the species (here, the Soolantra formulation) upon reading the disclosure. According to Teva, Manetta’s Soolantra is “undoubtedly a species within the scope of McDaniel’s disclosure.”

Federal Circuit said that Teva’s arguments ignore the axiom that a patent claim can only be invalid for anticipation if a single reference discloses each and every limitation of the claimed invention. Turning to another reference “for a very specific teaching” runs afoul of these settled principles.  Dart Indus., 726 F.2d at 727 (rejecting an anticipation challenge where the challenger relied on two additional articles “for a very specific teaching, not for any light they shed on what [the anticipatory reference] would have meant to those skilled in the art”). Here, the district court erred by finding the asserted claims anticipated by the disclosures of McDaniel and Manetta, in contravention of settled law. Because teaching of Manetta is specific one & not a general to shed light on McDaniel disclosure. McDaniel does not contain the specific disclosure that is necessary for a finding of anticipation: an ivermectin formulation (such as Soolantra®) that necessarily achieves the claimed efficacy limitations.

2. Inherency Based on Mere Possibility –

On appeal, Galderma argued that the district court erroneously found that McDaniel inherently discloses the claimed efficacy limitations. According to Galderma, the district court erroneously based this conclusion on the mere possibility that a POSA would have been able to practice McDaniel’s disclosed method with Soolantra®. Federal Circuit sided with Galderma & said that the proper inquiry for inherent anticipation is whether the claimed efficacy limitations “necessarily result” from practicing McDaniel. District court erred here because McDaniel does not disclose the “very same composition” as the patents-in-suit; it only discloses topical ivermectin formulations generally. The record does not show that practicing McDaniel’s general disclosure of 1% ivermectin, “formulated into a cosmetically-acceptable topical lotion, cream, or gel,” necessarily achieves the claimed efficacy limitations. Moreover, Teva’s own formulation expert testified that formulation parameters such as excipients can impact drug release, which affects whether a formulation has “any sort of therapeutic value.”

Federal Circuit thus reversed and remanded for the district court to consider Teva’s remaining invalidity defenses.