Merck Sharp & Dohme Corp. v. Hospira Inc., 221 F. Supp. 3d 497

Background

Plaintiff sued after Defendant filed an ANDA seeking approval to market a generic ertapenem (Invanz) product; Plaintiff asserts U.S. Pat. Nos. 5,952,323 (’323) and 6,486,150 (’150).
The ’323 patent claims a stable pharmaceutical formulation of ertapenem formed by creating a carbamate (carbon dioxide) adduct (formed at ~pH 6.0–9.0) to prevent dimerization and hydrolysis.
The ’150 patent claims a manufacturing process: charge a CO2 source solution (pH ~6–12), add base and active ingredient to maintain pH ~6–9 at low temperature, then lyophilize to <10% moisture to yield a final product with sufficient adduct to stabilize and minimize degradants.
Defendant conceded infringement of certain ’323 claims if valid; Defendant argued the ’323 claims were anticipated/obvious and certain claims lacked written description; Defendant argued the ’150 claims were invalid for obviousness and some prior-art anticipation.
The court held a bench trial: it rejected anticipation, obviousness, and written-description challenges to the asserted ’323 claims; it found claims 21–34 of the ’150 patent obvious and thus invalid. The ANDA product would have infringed the ’150 claims if they were valid.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether asserted claims of the ’323 patent are anticipated by Zeneca’s ’820 patent	’323 not anticipated; adduct formation requires pH 6–9 and ’820 does not teach that, so adduct not necessarily present	’820 inherently anticipates because it teaches mixing with carbonate/bicarbonate which allegedly would produce neutral pH and thus adduct formation	Held: Not anticipated — Defendant failed to show by clear and convincing evidence the adduct would necessarily form under ’820 teachings
Whether asserted ’323 claims are obvious over prior art (’820, Smith I, Primaxin label, Takeuchi III, Remington’s, etc.)	Nonobvious: prior art was inconclusive/contradictory, adduct stabilizing effect unexpected; evidence of commercial success and copying supports nonobviousness	Obvious: prior art pointed toward neutral pH formulation and would have motivated a skilled artisan to form the adduct with reasonable expectation of success	Held: Not obvious — prior art did not give reasonable expectation of success; secondary factors (commercial success, copying, unexpected result) support nonobviousness though commercial-success nexus partly weakened by blocking patent
Whether claims 4–6 of the ’323 patent lack written description because they omit a pH limitation	Written description adequate; specification discloses adduct forms only at pH ~6–9 so omission of pH in claims does not broaden beyond disclosed contribution	Claims broader than specification absent pH limitation, invalid under written-description principles (Gentry Gallery)	Held: Claims 4–6 meet written-description requirement; no essential-element rule forcing pH into the claims
Whether asserted claims 21–34 of the ’150 patent are invalid (obvious/anticipated) and whether Defendant infringes if valid	Plaintiff: process claims not obvious; secondary considerations (commercial success, copying) weigh against obviousness; claim 21 requires "high rate conversion" construed to require sufficient adduct to stabilize and minimize degradants	Defendant: claim 21 obvious over the ’323 patent and Almarsson (and routine optimization); Tsinontides slides do not anticipate claims; ANDA product contains sufficient adduct and would infringe	Held: Claims 21–34 invalid as obvious (prima facie obviousness established over both ’323 and Almarsson and routine optimization filled remaining gaps). Tsinontides manuscript did not anticipate. If valid, Defendant’s ANDA product would infringe, but the ’150 claims are invalid

Key Cases Cited

Callaway Golf Co. v. Acushnet Co., 576 F.3d 1331 (Fed. Cir.) (standard for anticipation via single prior-art reference)
Perricone v. Medicis Pharm. Corp., 432 F.3d 1368 (Fed. Cir.) (inherent anticipation requires that the missing descriptive material be necessarily present)
MEHL/Biophile Int’l Corp. v. Milgraum, 192 F.3d 1362 (Fed. Cir.) (inherent anticipation requires natural result flowing from operation taught)
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (U.S.) (obviousness framework and commonsense combination rationale)
Graham v. John Deere Co., 383 U.S. 1 (U.S.) (Graham factors for obviousness)
In re Cyclobenzaprine Hydrochloride Extended-Release Capsule Patent Litig., 676 F.3d 1063 (Fed. Cir.) (role of secondary considerations in obviousness analysis)
Par Pharm., Inc. v. TWI Pharm., Inc., 773 F.3d 1186 (Fed. Cir.) (inherency in obviousness analysis)