BioActive Laboratories v. BTG Intl Inc

1. Case Identification

• Case #: IPR2015-01305
• Patent #: 8,048,414
• Filed: May 29, 2015
• Petitioner(s): Bioactive Laboratories
• Patent Owner(s): BTG International Inc.
• Challenged Claims: 1-22

2. Patent Overview

• Title: Antivenom Composition Containing Fab Fragments
• Brief Description: The ’414 patent discloses antivenom pharmaceutical compositions containing antibody Fab fragments for treating snake envenomation. The technology is primarily directed to treating bites from snakes of the Crotalus genus (rattlesnakes) and includes compositions comprising Fab fragments alone or in mixtures with F(ab')2 fragments.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-7, 9-18, 21, and 22 under §102 by the ’352 Patent

• Prior Art Relied Upon: ’352 patent (Patent 4,489,352).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner’s central argument was that the ’414 patent was not entitled to its claimed priority date because its priority applications failed the written description and enablement requirements of 35 U.S.C. §112. This failure, Petitioner argued, makes the ’352 patent—which issued from a parent application in the priority chain and shares an identical specification with the ’414 patent—qualifying prior art under §102(b). Given the identical specifications, Petitioner contended that the ’352 patent necessarily discloses and enables at least one embodiment falling within the scope of each challenged claim, thereby anticipating them. For claim 1, the ’352 patent was alleged to teach an antivenom for snakebites comprising Fab fragments that bind specifically to Crotalus venom, are essentially free of contaminating Fc, contain a carrier, and neutralize venom lethality.

Ground 2: Obviousness of Claims 1-7, 9-18, and 20-22 under §103 over Chang in view of the WHO Report

• Prior Art Relied Upon: Chang (a 1969 immunochemical journal article) and the WHO Report (a 1981 publication on antivenoms).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Chang taught the core of the invention: an antivenom composition comprising papain-produced Fab fragments that were essentially free of contaminating Fc and proven effective at neutralizing the lethality of cobra venom. The primary element missing from Chang was the specific application to Crotalus genus venom. The WHO Report was cited to supply this element, as it described commercially available F(ab')2 antivenoms specifically for treating medically important Crotalus snakebites, establishing Crotalus as a known and logical target for antivenom development.
  • Motivation to Combine: A POSITA would combine the teachings to apply the known advantages of Fab-fragment antivenoms (safer, less immunogenic), as shown by Chang, to the well-known and dangerous Crotalus snakes identified in the WHO Report. The motivation was straightforward: to improve the safety and efficacy of existing Crotalus antivenoms by using a known, superior antibody fragment format.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success, as creating Fab fragments via papain digestion was a standard, predictable technique. Applying this known method to a different but analogous target (Crotalus venom instead of cobra venom) would have been seen as a routine extension of existing technology with predictable results.

Ground 3: Obviousness of Claims 8 and 19 under §103 over Chang in view of the WHO Report and Smith

• Prior Art Relied Upon: Chang, the WHO Report, and Smith (a 1979 immunology publication).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground specifically targeted claims 8 and 19, which recite mixtures of Fab and F(ab')2 fragments. Building on Ground 2, Petitioner used Smith to provide the rationale for combining these two types of fragments. Smith disclosed the distinct pharmacokinetic properties of Fab fragments (rapid onset, rapid clearance, wide distribution) and F(ab')2 fragments (longer half-life, less extensive distribution).
  • Motivation to Combine: A POSITA would combine Fab and F(ab')2 fragments to create a superior antivenom with a dual-action profile. The Fab fragments would provide rapid neutralization of venom, while the F(ab')2 fragments would provide sustained, longer-lasting activity. This combination would address the short half-life of Fab fragments, reducing the need for frequent re-dosing while maintaining immediate effectiveness.
  • Expectation of Success: Success was expected because the fragments were known to have distinct and complementary properties. A POSITA would predict they would function together without interfering, each contributing its known pharmacokinetic advantages to the overall composition.
• Additional Grounds: Petitioner asserted an additional obviousness challenge for claims 8 and 19 based on the ’352 patent in view of the WHO Report, which relied on similar combination rationales.

4. Key Claim Construction Positions

• "Essentially free from contaminating Fc": Petitioner argued for a construction of "not more than small, detectable levels of Fc," which importantly includes Fc from two sources: free Fc fragments and intact IgG molecules containing an Fc portion. Petitioner contended this construction was critical to achieving the patent’s stated goal of creating a safer antivenom by removing the components that cause serum sickness.
• "Fab fragments": Petitioner proposed a structural definition—"one of two upper fragments of the Y-shaped immunoglobulin molecule"—rather than a purely process-based definition (i.e., made by papain digestion). This broader construction was argued to be consistent with the Patent Owner’s own positions in a related ITC proceeding.

5. Key Technical Contentions (Beyond Claim Construction)

• Failure of Priority Claim: Petitioner’s primary technical contention, underpinning its anticipation ground, was that the ’414 patent’s priority applications failed to provide adequate written description and enablement for the full scope of the challenged claims. Petitioner argued that under the Patent Owner's broad construction from a related litigation, the claims cover compositions where the Fab fragments themselves do not need to neutralize venom, so long as the composition as a whole does. However, the priority documents allegedly only describe compositions where the Fab fragments are the active, neutralizing agent. This asserted mismatch between the claim scope and the supporting disclosure, Petitioner argued, breaks the priority chain under 35 U.S.C. §120.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-22 of Patent 8,048,414 as unpatentable.