Obviousness

Analysis of Obviousness under 35 U.S.C. § 103 for U.S. Patent 12,168,036

This analysis evaluates whether the claimed invention in U.S. Patent 12,168,036 would have been obvious to a Person Having Ordinary Skill in the Art (PHOSITA) at the time of the invention. An invention is considered obvious if the differences between the invention and the prior art are such that the subject matter as a whole would have been obvious to a PHOSITA.

Definition of a Person Having Ordinary Skill in the Art (PHOSITA)

A PHOSITA in the context of this patent would be a pharmaceutical scientist, biochemist, or chemical engineer. This individual would possess a master's degree or Ph.D. in a relevant field and have several years of experience in the development of liquid biologic formulations, particularly high-concentration monoclonal antibodies or therapeutic fusion proteins. The PHOSITA would be knowledgeable about protein stabilization, viscosity reduction, buffer systems, and the specific requirements and challenges of formulations intended for intravitreal administration.

Analysis of Independent Claims

The obviousness of the independent claims (1, 16, 21, 28, and 33) is analyzed below by considering combinations of prior art references.

1. Obviousness of Claims 1, 21, and 33 (High-Concentration Formulation with Arginine)

These claims cover a method of treatment, the formulation itself, and a method of manufacture, all centered on a specific high-concentration aflibercept formulation. The key elements are:

• Aflibercept at ~114.3 mg/mL
• Histidine-based buffer (10 mM)
• Sucrose (5% w/v)
• Polysorbate 20 (0.03% w/v)
• L-arginine monohydrochloride (50 mM)
• pH of ~5.8
• Specific viscosity and stability profiles

Primary Combination of Prior Art:

• US 2019/0343918 A1 (US '918) as the primary reference.
• General knowledge in the art regarding formulation development.

Motivation to Combine and Reasonable Expectation of Success:

A PHOSITA would have been motivated to develop a high-concentration aflibercept formulation to reduce the frequency of intravitreal injections, a well-known clinical need. The US '918 application, from the same inventors, explicitly addresses this exact problem.

1. Disclosure of All Elements: US '918 discloses all the essential components of the claimed formulation. It teaches the use of aflibercept at high concentrations (including 80 mg/mL, 140 mg/mL, and 150 mg/mL), histidine as a preferred buffer over phosphate for stability in some cases (Patent Text, Example 1), sucrose as a thermal stabilizer, polysorbate 20 as a surfactant, and L-arginine monohydrochloride as a viscosity-reducing agent (Patent Text, Example 2).

2. Explicit Example: The subject patent's own text identifies "Formulation GGGG" as comprising 114.3 mg/mL aflibercept, 10 mM histidine buffer, 5% sucrose, 0.03% polysorbate 20, and 50 mM L-arginine monohydrochloride at a pH of 5.8. (Patent Text, Illustrative Formulations). Crucially, the prior art reference US '918 discloses this nearly identical formulation and presents stability data for it (Patent Text, FIG. 19A-E). This figure in the patent, which analyzes a 114.3 mg/mL formulation with these components, demonstrates the stability that is a key feature of claim 21.

3. Obvious to Optimize: Even if US '918 did not disclose the exact combination in a single example, it provides a clear roadmap. It presents various formulations and studies the effect of changing individual components, such as comparing buffers (histidine vs. phosphate) and evaluating the effect of arginine (Patent Text, FIG. 2A, 4A). A PHOSITA, guided by the teachings of US '918, would have found it obvious to combine these disclosed elements and optimize their concentrations through routine experimentation to arrive at a formulation with the desired properties of stability, pH, and viscosity. The specific values recited in the claims represent successful endpoints of this routine optimization, not an inventive leap.

Therefore, claims 1, 21, and 33 would have been obvious over the teachings of US 2019/0343918 A1, as it provides all the necessary components and a clear motivation to combine them with a high expectation of success.

2. Obviousness of Claim 16 (High-Concentration Formulation without Arginine)

Claim 16 is directed to a method of treatment using a formulation comprising 80-150 mg/mL aflibercept, a histidine buffer, sucrose, and polysorbate 20, but without an agent like L-arginine. The claim specifies a viscosity of 11 cP to 14 cP at 20°C.

Primary Combination of Prior Art:

• US 2019/0343918 A1 (US '918) in combination with U.S. Patent 8,481,046 B2 (US '046).

Motivation to Combine and Reasonable Expectation of Success:

1. Starting Point: The PHOSITA starts with the goal of creating a high-concentration aflibercept formulation, as taught by US '918.
2. Optional Nature of Viscosity Reducers: US '918 teaches that viscosity is a problem at high concentrations and suggests arginine as a solution. However, the data presented in the '036 patent itself (derived from its priority applications) shows that omitting the viscosity reducer is a viable option. FIG. 3B shows that a 155 mg/mL aflibercept formulation in a histidine buffer with no salt has a viscosity of approximately 14 cP. This is within the range claimed in claim 16.
3. Simplification of Formulation: A PHOSITA is always motivated to create the simplest possible formulation that meets the required safety and efficacy profile. Since the viscosity of a histidine-buffered formulation without arginine was manageable and within the claimed range, it would have been an obvious design choice to omit the arginine to reduce complexity and potential side effects. The US '046 patent, describing the original EYLEA® formulation, establishes a baseline formulation that includes a buffer, stabilizer, and surfactant, but not necessarily a separate viscosity reducer like arginine for its 40 mg/mL concentration. A PHOSITA would consider whether such a reducer is truly necessary when increasing the concentration and would test formulations without it.
4. Achieving Claimed Viscosity: Based on the data in FIG. 3B of the patent's own disclosure (which reflects the state of the art available from the priority documents), a PHOSITA would have had a reasonable expectation of success in achieving a viscosity between 11 cP and 14 cP for an aflibercept formulation in a histidine buffer at a concentration between 80-150 mg/mL without adding arginine.

Thus, claim 16 would have been obvious, as formulating without a viscosity reducer is a known and obvious alternative, and the resulting viscosity was predictable and within an acceptable range for intravitreal injection.

3. Obviousness of Claim 28 (Pre-filled Syringe)

Claim 28 covers a pre-filled syringe containing the sterile pharmaceutical formulation of claim 21.

Primary Combination of Prior Art:

• The formulation of Claim 21 (found obvious above) in view of common general knowledge in the pharmaceutical field.
• US 2019/0343918 A1, which explicitly mentions pre-filled syringes.

Motivation to Combine and Reasonable Expectation of Success:

Packaging an injectable drug intended for precise ocular dosing into a pre-filled syringe is a standard, ubiquitous practice in the pharmaceutical industry. The benefits—convenience, reduced risk of contamination, and improved dosing accuracy—are well-established. US '918 explicitly discloses that its high-concentration formulations can be introduced into a "delivery device, e.g., a pre-filled syringe."

Therefore, once the formulation of claim 21 is established (or rendered obvious), the final step of packaging it into a pre-filled syringe is nothing more than the "predictable use of prior art elements according to their established functions" and would have been immediately obvious to a PHOSITA.

Conclusion on Obviousness

The claims of U.S. Patent 12,168,036 appear to be vulnerable to an obviousness challenge under 35 U.S.C. § 103. The primary prior art, particularly Regeneron's own earlier patent application US 2019/0343918 A1, discloses the key problem, the specific components needed for the solution, and data demonstrating a high likelihood of success. The claimed formulations represent, at best, the result of routine optimization and combination of known elements for their intended purposes, a pathway clearly illuminated by the prior art. The packaging of such a formulation in a pre-filled syringe is similarly a standard and obvious practice. The arguments laid out in the ongoing PGR proceedings likely expand on these points in greater detail.