Heart monitor maker iRhythm Technologies cannot get an early win in a proposed investor class action alleging it made misleading disclosures about one of its devices, a San Francisco federal judge has determined.

In a Friday order, U.S. District Judge Jacqueline Scott Corley denied iRhythm's request for judgment on the pleadings on the suit's remaining claims, finding that it would be improper for her to reconsider earlier rulings on allegations that iRhythm CEO Quentin Blackford intentionally misled investors or that investors saw losses after iRhythm made disclosures about its Zio AT heart-event monitoring device.

"The court previously ruled plaintiff adequately alleged Mr. Blackford's scienter and loss causation in its order on defendants' motion to dismiss, so the law of the case doctrine prohibits the court from re-examining those issues absent a motion for reconsideration," Judge Corley said Friday.

Judge Corley previously trimmed certain claims from the suit in June. In the company's July motion for judgment on the pleadings, iRhythm told Judge Corley that Zio AT used labels during much of the proposed class period that had "extensive, explicit" information about how the limits of how much data the devices could transmit to a patient's care team. The investor suit alleged the company concealed those limits.

"The operative versions of the Zio AT label during the class period ... doom any inference of scienter," iRhythm said in July.

But on Friday, Judge Corley said that regardless of the company's labels, its class period "public statements about the transmission limit issue were vague at best."

The investor claims center on the San Francisco-based company's representations that the Zio AT could provide patients' doctors with "near real-time" notifications regarding instances of arrhythmia; the company's claims the device was appropriate for "high-risk" patients, and assertions about the devices' "incredible accuracy."

In truth, the investors have claimed, the company was on notice since 2022 that the FDA disputed those assertions.

For example, the regulator asserted in 2022 that the "Zio AT was a contributing factor [in a] patient's death. The FDA also said the device was not a good fit for high-risk patients because limits on how much it could transmit might prevent the timely treatment of certain life-threatening arrhythmias.

The suit launched in February 2024, and in the most recent version of the claims, from October 2024, the investor alleged that between November 2021 and August 2024, trading prices for iRhythm shares fell 62%, or over $105, from a class period high of nearly $170 to under $65 at the end of the proposed class period as a result of a series of alleged corrective disclosures about the Zio AT.

In June, Judge Corley trimmed claims from the suit that Zio AT is a "mobile cardiac telemetry" device, finding at the time that the suit failed to provide a definition for an MCT device. She also trimmed claims against individual defendants other than Blackford.

The latest filing comes days after the institutional investor leading the action sought certification for a class of iRhythm investors purportedly numbering in the thousands.

Alongside her early win denial, Judge Corley on Friday shot down a request to extend the case deadlines amid a lengthy government shutdown.

On Monday, counsel for the investors declined to comment and counsel for iRhythm did not immediately respond to requests for comment.

The pension fund is represented by John J. Rizio-Hamilton, Katherine M. Sinderson, Thomas Z. Sperber, Abby Kritta and Jonathan D. Uslaner of Bernstein Litowitz Berger & Grossmann LLP.

IRhythm and the individual defendants are represented by Kristin Tahler, Christopher Porter, Jesse Bernstein, Brenna Nelinson and Amy Shehan of Quinn Emanuel Urquhart & Sullivan LLP.

The case is Glazing Employers and Glaziers Union Local #27 Pension and Retirement Fund v. iRhythm Technologies Inc. et al., case number 3:24-cv-00706, in the U.S. District Court for the Northern District of California.