Biosimilar Patent Law

The Biologics Price Competition and Innovation Act (BPCIA) was enacted as part of the Affordable Care Act in 2010 and created the regulatory and patent framework for biosimilar competition in the United States: WHAT BPCIA DOES: creates the § 351(k) pathway for biosimilar Biologics License Applications (BLAs); allows biosimilar applicants to rely on the safety and efficacy data of the reference biologic (like Hatch-Waxman for small molecules); creates the patent resolution framework (patent dance); establishes 12-year data exclusivity for reference biologics; WHY BIOLOGICS ARE DIFFERENT FROM SMALL MOLECULES: small molecules are relatively simple chemical structures that can be reproduced exactly by generic manufacturers (generic = identical); biologics are large, complex proteins (antibodies, growth factors, blood-forming proteins) made in living cell systems; biologics are sensitive to manufacturing conditions; even the reference product manufacturer cannot guarantee batch-to-batch identity; a biosimilar is SIMILAR TO, not IDENTICAL TO, the reference biologic; there is no concept of a 'generic biologic' — only biosimilars; THE 12-YEAR DATA EXCLUSIVITY: the most important structural difference from Hatch-Waxman; the FDA cannot approve a biosimilar BLA under § 351(k) until 12 years after the reference biologic was first licensed; a 4-year bar means no § 351(k) application can be submitted within 4 years of reference biologic approval; compare to Hatch-Waxman: 5-year NCE exclusivity (with ANDA filing allowed after 4 years for Para IV); THE PATENT DANCE vs. ORANGE BOOK: Hatch-Waxman: patent holder lists patents in the Orange Book; ANDA filer certifies against each listed patent; automatic 30-month stay triggered by lawsuit; no negotiation of which patents to challenge; BPCIA: complex 12-step information exchange (patent dance); biosimilar applicant provides application information; reference product sponsor provides patent list; parties negotiate which patents to litigate first; no automatic stay — the 30-month stay equivalent requires courts to apply four-factor analysis; THE KEY DIFFERENCES AT A GLANCE: Hatch-Waxman: small molecules; 5-year NCE exclusivity; Orange Book; automatic 30-month stay; para IV certification; BPCIA: biologics; 12-year exclusivity; patent dance; no automatic stay; case-by-case litigation following dance; 180-day notice required; NO ANDA equivalent; INTERCHANGEABILITY: BPCIA created an additional designation — 'interchangeable' biosimilar — for biosimilars that meet a higher standard; an interchangeable biosimilar can be substituted at the pharmacy without prescriber intervention (like generic drug substitution); 1-year exclusivity for first interchangeable designation.

The BPCIA patent dance is a 12-step information exchange process designed to identify which patents are at issue before biosimilar launch, but its mandatory nature was contested for years: THE PATENT DANCE STEPS (abbreviated): STEP 1: within 20 days of FDA acceptance of the § 351(k) biosimilar BLA, the biosimilar applicant provides a copy of the application and manufacturing information to the reference product sponsor (RPS); STEP 2: within 60 days, RPS provides a list of patents it believes could be enforced against the biosimilar applicant; STEP 3: within 60 days of step 2, biosimilar applicant provides a list of patents it believes should be subject to litigation and its positions on validity/non-infringement for each; STEP 4: within 60 days of step 3, RPS provides its response to the biosimilar applicant's positions; STEP 5: within 15 days of step 4, parties negotiate to identify patents for immediate litigation (list 1 patents); STEP 6: if agreement reached, parties file action within 30 days on list 1 patents; if no agreement, RPS selects ≤ a specific number of patents for list 1 and files suit; LATER STEPS: additional patents (list 2 patents) can only be asserted after the biosimilar applicant gives 180-day notice of commercial marketing; these are the 'post-notice' patents; THE MANDATORY QUESTION — AMGEN v. SANDOZ (S.Ct. 2017): Sandoz took the position that the patent dance was OPTIONAL; if biosimilar applicant does not provide the application under step 1, the reference product sponsor's remedy is limited to seeking immediate suit under § 271(e)(2); the Supreme Court agreed: the patent dance is NOT mandatory; a biosimilar applicant can decline to provide the § 351(k) application to the RPS; the consequence is that the RPS can sue for patent infringement immediately and all non-listed patents are deemed list 2 patents subject to the 180-day notice requirement; MANDATORY vs. OPTIONAL IN PRACTICE: while the dance is technically optional, opting out has strategic consequences; participating in the dance can narrow the patents in dispute and prevent surprise litigation; many biosimilar applicants participate in the dance to get certainty about which patents will be asserted; STRATEGIC IMPLICATIONS: biosimilar applicants may opt out when they have strong invalidity positions they don't want to reveal early; RPS can use the dance to identify the biosimilar's manufacturing details; biosimilar applicant can use the dance to force early identification of which patents the RPS actually believes are infringed.

Biologic drug patents span a much wider range of patent types than small-molecule pharmaceutical patents because biologics are manufactured products, not chemical syntheses: ANTIBODY PATENT TYPES (most commercially important biologic class): (1) STRUCTURAL ANTIBODY PATENTS: VH and VL domain sequences; CDR sequences; specific amino acid sequences; these are the core IP protecting the antibody itself; (2) Fc ENGINEERING PATENTS: modifications to the antibody constant (Fc) region for enhanced effector function (ADCC; CDC); Fc modifications for extended half-life (YTE; LS mutations); (3) ANTIBODY-DRUG CONJUGATE PATENTS: the specific linker chemistry; conjugation site; drug-antibody ratio; payload; (4) BISPECIFIC ANTIBODY FORMATS: specific architecture for making bispecific antibodies (knob-in-hole; CrossMab); MANUFACTURING/CELL LINE PATENTS: Chinese hamster ovary (CHO) cell lines expressing the biologic; cell culture media compositions; fermentation conditions; glycosylation control; because biologics are made in living cells, the manufacturing process is patent-protectable in ways that small-molecule synthesis usually is not; manufacturing patents are often the most durable because they are hardest for biosimilar manufacturers to design around; PURIFICATION PROCESS PATENTS: Protein A affinity chromatography; ion exchange polishing steps; viral clearance; these are typically less commercially significant but add layers of protection; FORMULATION PATENTS: specific protein concentration; buffer type (histidine; succinate; citrate); stabilizers (sucrose; trehalose; polysorbate 80); pH; container closure system; devices (auto-injector; prefilled syringe); formulation patents are often the last patents to expire and can extend commercial exclusivity significantly; METHOD OF TREATMENT PATENTS: dosing regimen (specific dose and interval); patient selection (biomarker); combination therapy; indication expansion; HOW THESE DIFFER FROM SMALL-MOLECULE PHARMA PATENTS: small molecules: chemistry patents (compound); formulation patents; method of use patents; process patents; biologics ADD: manufacturing cell line patents; process/purification patents; glycoform control patents; post-translational modification patents; BIOBETTER STRATEGY: when the originator biologic faces biosimilar competition, the brand may launch a 'biobetter' — an improved version with better efficacy, safety, or convenience; the biobetter itself generates new patents (modified sequence; Fc engineering; improved formulation) that restart the patent clock for the improved molecule.

The 180-day pre-commercial marketing notice under BPCIA is a critical strategic tool that determines when biosimilar litigation escalates to preliminary injunction proceedings: THE STATUTORY REQUIREMENT: 42 U.S.C. § 262(l)(8)(A): the biosimilar applicant must give the reference product sponsor notice at least 180 days before commercial marketing; this requirement is MANDATORY (unlike the patent dance, which the Supreme Court held optional in Amgen v. Sandoz); the notice can be given AFTER FDA approval of the biosimilar but BEFORE launch; AMGEN v. SANDOZ (S.Ct. 2017) CONFIRMED: even if the patent dance is not followed, the 180-day notice is mandatory; the biosimilar applicant must give 180-day notice before commercial marketing of an approved biosimilar; A reference product sponsor who receives the 180-day notice can seek a preliminary injunction to prevent launch during the 180 days; PURPOSE OF THE 180-DAY NOTICE: gives the RPS time to seek emergency preliminary injunction if any patents were not resolved in the patent dance; ensures the RPS knows which day commercial launch will begin; allows the market (payers, prescribers, patients) to prepare for biosimilar entry; PRELIMINARY INJUNCTION AFTER NOTICE: when a RPS files for preliminary injunction after receiving 180-day notice, courts apply the standard four-factor test: (1) likelihood of success on the merits; (2) irreparable harm; (3) balance of hardships; (4) public interest; BIOLOGIC MARKET PRICING CONSIDERATIONS: biosimilars typically launch at 15-35% below the reference biologic price (not the 80-90% discount seen with small-molecule generics); the 12-year exclusivity + patent dance + patent portfolio + complexity of substitution create higher barriers to biosimilar competition than Hatch-Waxman creates for small molecules; LAUNCH AT RISK: biosimilar manufacturers sometimes choose to launch 'at risk' (before patent disputes are fully resolved) accepting potential liability for post-launch damages if the patent is ultimately found valid and infringed; the economics depend on the size of the market, the strength of the patent, and the likely damages calculation.