4th Cir.

Vir2us, Inc. v. Sophos Inc.

June 23, 2026 ·25-1158 ·Per Curiam · By Maria Santos

The Fourth Circuit affirmed a district court ruling that Sophos products were not subject to royalty payments under a patent license agreement. The court held that sharing source code does not make a product a legal derivation of a containerized product when the shared code is unrelated to the product's primary function.

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Background

Vir2us, Inc. sued Sophos Inc. and Invincea, Inc. for breach of contract regarding a patent license agreement. The dispute centered on whether Sophos products containing shared source code with Invincea’s containerized products qualified as Container Products subject to royalty payments. The district court granted summary judgment to the defendants, finding the products were not derivations of the accused container products.

The court’s reasoning

The court applied Virginia law to interpret the contract’s plain meaning. It defined derivation as requiring a product to originate from or be developed from a specific source. The court found that the Sophos products existed before the source code was integrated and that the shared code was for machine learning, not the containerization technology that defined the accused products. The court concluded that mere presence of common source code, especially when unused in the originating product, does not constitute a derivation.

What it means going forward

The ruling clarifies that royalty obligations in patent settlements are strictly limited to products that are direct derivations of the licensed technology, preventing broad interpretations based solely on shared code.