Case Overview

In a swift but consequential procedural ruling, the U.S. Court of Appeals for the Federal Circuit dismissed CareDx, Inc.’s appeal in Natera, Inc. v. CareDx, Inc. (Case No. 24-1357) on March 13, 2024—just 61 days after the notice of appeal was filed. The dismissal, grounded not in substantive patent law but in procedural non-compliance, effectively closed a high-stakes dispute involving four U.S. patents covering cell-free DNA (cfDNA) amplification and noisy genetic data analysis technologies central to organ transplant diagnostics.

For patent litigators and IP professionals, the case offers a striking reminder: even the most technically complex genomic patent disputes can be extinguished through procedural failure. For R&D teams operating in the transplant diagnostics and liquid biopsy space, the underlying patents—covering foundational cfDNA methodologies—remain active and enforceable, carrying significant freedom-to-operate implications.

The Parties

Patents at Issue

This dispute involved four U.S. patents protecting core computational and molecular biology workflows underlying cfDNA-based transplant rejection testing. These technologies are directly relevant to both parties’ commercial platforms.

• • US10655180B2 (App. No. US16/353636) — Methods for simultaneous amplification of target loci
• • US10597724B2 (App. No. US16/411507) — System and method for cleaning noisy genetic data and determining chromosome copy number
• • US10526658 (App. No. US16/412331) — System and method for cleaning noisy genetic data from target individuals
• • US11111544B2 (App. No. US16/823127) — System and method for cleaning noisy genetic data using data from genetically related individuals

The Verdict & Legal Analysis

Outcome

The Federal Circuit issued an order dismissing the appeal for procedural non-compliance. The order stated: “The appellant having failed to file the required Entry of Appearance form by an attorney admitted to the bar of this court, and having failed to file the brief required by Federal Circuit Rule 31(a) within the time permitted by the rules, it is ORDERED that the notice of appeal be, and the same hereby is, DISMISSED, for failure to prosecute in accordance with the rules.”

The appeal was dismissed with no merits review of the underlying infringement claims, validity challenges, or claim construction arguments. No damages figure or injunctive relief determination was issued at the appellate level. The basis of termination is formally recorded as Appeal Dismissed.

Key Legal Issues

The dismissal arose from two independent procedural failures by CareDx:

1. Failure to file an Entry of Appearance by a Federal Circuit bar-admitted attorney.
2. Failure to file the opening brief under Federal Circuit Rule 31(a) within the time permitted.

These failures constitute a “failure to prosecute,” a doctrine allowing courts to dismiss cases where a party abandons procedural participation. The Federal Circuit applies these rules rigorously, particularly at the appellate stage where litigation resources are concentrated.

From a substantive patent law perspective, this dismissal carries no precedential value on cfDNA patent validity, claim construction, or infringement doctrine. However, it has significant procedural precedent value, reaffirming the Federal Circuit’s strict enforcement of its rules.