1.) June ANDA Approvals, Formulation Tech and 2.) CAFC Patent Decisions: Why the Federal Circuit Invalidated Enanta’s Protease Inhibitor Patent Against Pfizer

Two minutes read

Pharma Regulatory & IP Digest: June 2026 ANDA Approvals, Tech-Driven Formulations, and Landmark Federal Circuit Ruling

Welcome to the Sidvim LifeSciences monthly briefing. This month, we cover key US FDA generic approvals, evolving formulation technology trends, and a major Federal Circuit patent decision on priority documentation.

1. USFDA ANDA Approvals Dashboard (June 2026)

In June 2026, the USFDA granted 94 ANDA approvals, which included 11 tentative approvals. Tentative approvals indicate that a generic formulation meets all scientific and quality benchmarks but is held back from immediate commercial rollout due to unexpired patent terms or market exclusivities held by the innovator.

The leading generic developers securing approvals during this period include:

• Alembic: 6 approvals

• Aurobindo & MSN: 5 approvals each

• Apotex, Micro Labs, Mylan, Teva, & Zydus: 4 approvals each

• Amneal & Macleods: 3 approvals each

• Concord Biotech, Sun Pharma, & others: 2 approvals each

Key Generic Product Highlights

• Eribulin Mesylate Injection (Natco / Lupin | ANDA #217085): Approved as a bioequivalent to Eisai's Halaven®. It targets metastatic breast cancer and liposarcoma, entering a multi-source market where Gland/Orbicular previously opened the door as the first generic in 2024. Brand sales hovered around USD 43.7 million annually.

• Phytonadione Injectable Emulsion USP, 10 mg/mL (Amneal | ANDA #217734): A critical Vitamin K replacement indicated for severe coagulation disorders. Because the RLD (AquaMEPHYTON®) is discontinued, filers utilise Cipla's approved formulation as the designated Reference Standard (RS) for testing. The specialised market is valued at roughly USD 44 million per year.

• Mycophenolate Mofetil Oral Suspension, 200 mg/mL (Concord Biotech | ANDA #218566): Generic equivalent to Roche’s CellCept, prescribed to prevent organ transplant rejection. This product addresses an estimated USD 30 million market opportunity in the U.S.

• Fluorescein Injection USP, 10% & 25% (Zydus | ANDA #218651): An essential diagnostic imaging agent used in retinal angiography, equivalent to Alcon's Fluorescite®. The global market for this agent is expanding toward USD 120 million.

• Dextromethorphan HBr & Quinidine Sulfate Capsules (Sun Pharma | ANDA #204196): Generic alternative to Nuedexta® for pseudobulbar affect (PBA), a space with peak brand value between USD 300 million and USD 350 million. Key method-of-use patents expire in August 2026, clearing a regulatory path for multiple generic entrants.

2. General Industry & Formulation Tech Insights

• Patient-Centric Dosage Forms: A high patient nonadherence rate (30%–50%) fueled by complex dosing schedules is pushing the industry toward tailored formulations. Recent clinician-formulator efforts yielded palatable, plant-excipient pediatric antibiotic options.

• 3D Printing & AI Development: Additive manufacturing shows promise for multi-API, staggered-release dosage forms in oncology and rare diseases. However, the commercial scale is restricted by limited regulatory precedents. Furthermore, internal audits reveal data-cleaning issues in machine learning pipelines, with only 3% of historical formulation datasets ready for AI training.

• PDUFA Date Set for Roflumilast Cream: The USFDA accepted Arcutis Biotherapeutics’ sNDA for Zoryve (roflumilast cream 0.05%) for treating atopic dermatitis in infants down to 3 months of age, establishing a PDUFA target date of February 23, 2027.

3. Intellectual Property Spotlight

CAFC Decides Enanta Pharmaceuticals, Inc. v. Pfizer Inc. (Appeal No. 2025-1427)

On June 23, 2026, the Federal Circuit affirmed a summary judgment ruling that completely invalidated all claims of Enanta’s U.S. Patent No. 11,358,953 ('953 patent). Enanta had alleged that Pfizer’s blockbuster COVID-19 antiviral, Paxlovid® (nirmatrelvir), infringed its intellectual property.

Enanta '048 Provisional (2020):  -NHC(O)-C2-C12-alkyl  (Excludes C1)
                                         │
Intervening Pfizer Disclosure (April 2021): Nirmatrelvir uses a C1 substituent
                                         │
Enanta '953 Non-Provisional (Nov 2021):  -NHC(O)-C1-C12-alkyl  (Attempted Correction)

The dispute centred on whether Enanta could claim the priority date of its '048 provisional application filed in July 2020. The provisional application defined a chemical substituent range as -NHC(O)-C2-C12 -alkyl, whereas the subsequent non-provisional application modified the range to -NHC(O)-C1-C12 -alkyl to capture single-carbon (C1) structures like Pfizer's nirmatrelvir. Enanta argued the original script was a minor typographical error.

The Federal Circuit firmly rejected this defence, reinforcing that "2" is structurally different from "1". Under 35 U.S.C. § 112, priority requires the earlier specification to explicitly demonstrate possession of the exact chemistry claimed later. The Court noted that extrinsic expert testimony cannot add new matter to a patent filing. Without the 2020 priority date, Pfizer's own April 2021 public presentation served as invalidating prior art.

-----------xx----------xx----------------

Thank you for reading the above summary. I would like to encourage you to read the detailed notes below. 

Contents

ANDA approvals-June 2026

General information

The Next Generation of Medicine: Personalized, Preventive, and Powered by Technology

US FDA Sets PDUFA for Roflumilast Cream 0.05% in Infants With AD

Intellectual Property

Federal Circuit Decision: Enanta Pharmaceuticals, Inc. v. Pfizer Inc.

ANDA approvals-June 2026

We follow ANDA approvals.

In June 2026, the USFDA issued 94 ANDA approvals, of which 11 were tentative. 

A tentative approval is a formal notification from the USFDA indicating that a generic drug application has met all scientific and regulatory requirements for safety, efficacy, and quality, but cannot be granted final marketing approval due to unexpired patents or market exclusivities held by the original brand-name drug.

The companies that could seek more than two ANDA approvals (including tentative ones) in June were as follows. 

Some of our other comments about a few ANDA approvals sought by Indian companies are listed below.

General information

The Next Generation of Medicine: Personalized, Preventive, and Powered by Technology

• Patient nonadherence rates of 30%–50% are linked to dosing complexity and poor acceptability, motivating patient-centered formulation strategies, especially for pediatrics and older adults.
• A clinician–formulator collaboration produced a plant-excipient pediatric antibiotic gummy with required performance and improved palatability, illustrating movement beyond standardized tablets toward tailored dosage forms.
• Additive manufacturing enables individualized multi-API and staggered-release products that reduce pill burden and support precision dosing, with particular relevance to oncology and rare diseases.
• Commercialization of 3D-printed drugs is constrained by excipient-dependent printability and release properties, limited regulatory precedent (one FDA-approved product), and the need for clearer approval pathways.
• AI-driven formulation and documentation require complete, interoperable datasets and robust governance; internal audits showed only 3% of 20,000 experiments were trainable, emphasizing data discipline and traceability.

News here

US FDA Sets PDUFA for Roflumilast Cream 0.05% in Infants With AD

The US Food and Drug Administration (FDA) has accepted Arcutis Biotherapeutics, Inc.’s supplemental New Drug Application (sNDA) for roflumilast cream 0.05% (Zoryve) to expand the indication for the topical treatment of mild-to-moderate atopic dermatitis (AD) to include infants aged three to 24 months.

The FDA has set a PDUFA target action date of February 23, 2027.

News here

Intellectual Property 

Federal Circuit Decision: Enanta Pharmaceuticals, Inc. v. Pfizer Inc.

On June 23, 2026, the United States Court of Appeals for the Federal Circuit (CAFC) issued a decision in Enanta Pharmaceuticals, Inc. v. Pfizer Inc. (Appeal No. 2025-1427). The panel, consisting of Circuit Judges, affirmed the U.S. District Court for the District of Massachusetts’ grant of summary judgment in favour of Pfizer. The court held that all claims of Enanta's U.S. Patent No. 11,358,953 ('953 patent) are invalid as anticipated by an intervening public disclosure by Pfizer due to a failure to meet the written description requirement under 35 U.S.C. § 112 for its claimed priority date. 

Procedural History and Backstory

Enanta filed its non-provisional application on November 9, 2021, seeking priority from U.S. Provisional Patent Application No. 63/054,048 ('048 provisional), which was filed on July 20, 2020. The technology in question involves chemical compounds and methods engineered to inhibit coronavirus replication activity. 

In June 2022, Enanta sued Pfizer, claiming that Pfizer's blockbuster antiviral product, Paxlovid (which contains the protease inhibitor nirmatrelvir), infringed the claims of the '953 patent. Pfizer counterclaimed for invalidity and moved for summary judgment, asserting that the '953 patent was anticipated by Pfizer's own public presentation on April 6, 2021, which disclosed nirmatrelvir. 

Because Pfizer’s presentation occurred between the filing of Enanta's 2020 provisional and its 2021 non-provisional application, the case hinged entirely on whether Enanta was legally entitled to claim the earlier 2020 priority date. If the priority chain failed, Pfizer’s disclosure stood as invalidating prior art. 

The Chemical Discrepancy: C2 vs. C1  

The core dispute rested upon a single digit within the detailed chemical definitions listed in the respective patent specifications. 

• The '048 Provisional Definition: Enanta's provisional specified an allowable chemical substituent as -NHC(O)-C2-C12-alkyl.
• The '953 Patent Definition: Enanta's issued patent altered the range to -NHC(O)-C1-C12-alkyl.

The structural modification is critical: the provisional application described a range of alkyl groups starting at two carbon atoms (C2), effectively excluding a single-carbon alkyl group (C1). However, Pfizer’s nirmatrelvir molecule utilises an "A" group substituted with a -NHC(O)-C1-alkyl  group. Enanta claimed it noticed this "typographical error" in July 2021 and corrected the script from C2 to C1  in the non-provisional filings to encapsulate the single-carbon layout. 

Now examine Paxlovid's structure above. Pay attention to the circled part, which is a C1 substitution. It is not covered in '048 provisional, as it covers -NHC(O)-C2-C12-alkyl.

Federal Circuit's Written Description & Priority Analysis

The District Court originally granted summary judgment, ruling that the "C2" text was not an obvious typographical error that the court could correct, making the change an impermissible broadening of the patent's scope. 

On appeal, the Federal Circuit bypassed the district court’s focus on its inherent equitable powers to correct typographical errors, choosing instead to review the matter de novo by directly applying the statutory written description standard of 35 U.S.C. § 112 for priority tracking. Under long-standing precedent, for a non-provisional application to capture an earlier provisional's date, the provisional's disclosure must clearly show that the inventor was in complete possession of the later-claimed invention at the time of the original filing. 

The Federal Circuit ruled that "2" is simply different from "1." Because the '048 provisional explicitly defined a range starting at C2 and omitted any mention of a C1 alkyl group within that specific structural substituent block, it failed to provide written description support for the  C1 variations claimed in the '953 patent. 

The Court was unpersuaded by Enanta’s expert declaration, which argued that an ordinary artisan would recognise an internal mismatch within the provisional’s broader "alkyl" definition section (where the numeral  “C2-C12” was paired with the text "one to twelve... carbon atoms"). Judge Lourie noted that an error elsewhere in the generic definitions does not change the plain language of the specific chemical moieties detailed under the definition of "substituted." Extrinsic expert opinions cannot vary the plain text of a patent application to add matter that was not originally disclosed. 

To illustrate the severity of the chemical distinction, the Court offered a sharp analogy: a disclosure of ethanol (a two-carbon alcohol safely consumed by humans) cannot serve as a valid written description disclosure for methanol (a one-carbon alcohol highly toxic to humans). 

Final Ruling and Key Takeaways

Because the '048 provisional did not explicitly disclose or demonstrate possession of the -NHC(O)-C1-alkyl chemistry, the '953 patent failed to maintain its 2020 priority date. Consequently, Pfizer’s April 2021 public presentation of nirmatrelvir stands as legally valid prior art that completely anticipates and invalidates Enanta’s claims. The Federal Circuit affirmed the summary judgment of invalidity. 

This decision reinforces the absolute necessity of rigorous quality control in provisional drafting. Even minor single-digit clerical oversights in chemical ranges cannot be salvaged as "obvious typographical errors" if they expand the structural footprint of a patent against intervening competitor disclosures.

Decision here

#PharmaRegulations, #ANDAWactch, #IntellectualProperty, #PharmaPatents, #GenericDrugs, #FDAApproval, #BiotechIP, #FormulationTech