On Aug. 18, 2022 , Delaware court found Velphoro® patent valid and infringed in a Hatch-Waxman litigation.
Plaintiffs (Vifor Fresenius) sued defendant (Teva) for infringement of US 9,561,251 patent as defendant filed ANDA seeking to launch generic version of Velphoro® (Sucroferric oxyhydroxide) chewable tablet. Velphoro is “a phosphate binder indicated for the control of serum phosphorus levels in patients with chronic kidney disease on dialysis.” The ’251 patent is directed to pharmaceutical compositions with a high load of iron oxy-hydroxide – at least 500 mg iron oxy-hydroxide in oral dosage form. Vifor asserted claims 29, 30, 33, and 56 against Teva. Teva denies infringement of claims 29 and 30 and asserts that all four of the asserted claims are invalid.
The only dispute regarding infringement of claim 29, is whether Teva’s ANDA product meets the “essentially non-bioabsorbable” limitation. Based on drug label and other documents court concluded that Teva’s ANDA product is not absorbed in clinically significant amounts and thus meets the claim limitation. Free iron absorption can lead to toxicity and thus development was intended to avoid having free iron that can be absorbed.
With respect to claim 30, the question is whether Teva’s ANDA product meets the additional limitation of claim 30, i.e., “having an iron release rate of below 2.5% w/w.” Dr. Myers (plaintiff’s expert) performed iron release testing consistent with the Court’s construction and found that tablets of Teva’s ANDA product had an average iron release rate of 1.94% w/w, ranging from 1.51 to 2.35% w/w at a pH that ranged from 3.22 to 3.28. Therefore, Teva’s ANDA product also met this claim limitation.
Obviousness – In essence, all asserted claims require a “pharmaceutical composition” with “at least 500 mg” of iron oxy-hydroxide “per dosage form.” Court said that a POSA would not have been motivated to make a single dosage form with at least 500 mg or about 800 mg of iron oxy-hydroxide based on the disclosure of prior arts. The prior arts does not disclose any complete pharmaceutical compositions, let alone any high loaded compositions. Thus, a POSA would not have had reason to believe that a single dose containing 500 or 800 mg iron oxy-hydroxide would be successful as a pharmaceutical formulation. Important to note that compressing 500 milligrams of iron in a small tablet is “remarkable,” particularly given the “very minimal” gastrointestinal adverse events. Moreover, secondary consideration such as long-felt need, commercial success favour non-obviousness.
Lack of enablement – Teva also argued that claims 29 & 30 are invalid under lack of enablement. Court said that a POSA, following the disclosure in the ’251 patent, could generate the claimed compositions that are essentially non-bioabsorbable without undue experimentation. The ’251 patent provides numerous working examples of complete formulations, including chewable tablets with iron release rate as low as 0.2%. The ’251 patent also provides guidance about manufacturing techniques that should be avoided in order to prevent the release of iron.