BioTech IP Review

Assignee: Cidara Therapeutics, Inc.
Patent Number: 12,427,200 B2
Filed: August 15, 2022
Issued: September 30, 2025
Inventors: Allen Borchardt, Thomas P. Brady, Zhi‑Yong Chen, Thanh Lam, Leslie W. Tari
Classification: Therapeutics — Antiviral drug‑Fc conjugates

What This Patent Covers

This patent protects novel therapeutic conjugates and methods for treating viral infections, focusing on drug‑Fc fusion constructs that combine a viral inhibitor with an antibody Fc fragment or related long‑lived protein domain.

Key elements include:

• Viral inhibitor conjugates: Compositions where an antiviral agent (especially a viral neuraminidase inhibitor such as zanamivir, peramivir, or analogs) is covalently linked to an Fc monomer, Fc domain, or an Fc‑binding peptide/albumin unit.
• Extended half‑life & immune engagement: The Fc/albumin component extends circulation time and can engage immune effector functions, potentially improving both duration and efficacy compared to unconjugated small‑molecule antivirals.
• Methods of use: Includes pharmaceutical compositions and methods for treating viral infections (e.g., influenza) using these drug‑Fc conjugates.

This type of conjugate leverages Cidara’s Cloudbreak® drug‑Fc conjugate platform, which is designed to create long‑acting antiviral therapeutics that can protect patients from virus‑mediated disease with extended dosing intervals.

Why This Patent Is Important

• Core to lead asset CD388: Although the original foundational patent on CD388’s composition was issued earlier, US 12,427,200 B2 (2025) expands Cidara’s IP coverage around next‑generation antiviral conjugates, complementary to CD388 and potentially covering broader inhibitor linkage approaches.
• Strategic value in acquisition: Cidara’s pipeline — including CD388, which is in late‑stage clinical development for universal influenza prevention — was a primary driver of its nearly $9.2 billion acquisition by Merck in 2025.
• Commercial exclusivity: Patent protection through this composition and method broadens market exclusivity for specific DFC (drug‑Fc conjugate) therapeutics, making it harder for competitors to replicate such long‑acting antiviral drugs.
• Broad antiviral scope: While exemplified with influenza, the underlying technology could be adapted to other viral targets by altering the linked antiviral moiety — a versatile platform strategy.