Ultragenyx Pharmaceutical Inc. Notice of April 6, 2026 Application Deadline for Class Action Lawsuit - Contact Lewis Kahn, Esq. at Kahn Swick & Foti, LLC, Before Application Deadline

Rhea-AI Summary

News Market Reaction – RARE

-12.68% 2.2x vol

85 alerts

-12.68% News Effect

-11.5% Trough in 5 hr 47 min

-$329M Valuation Impact

$2.27B Market Cap

2.2x Rel. Volume

On the day this news was published, RARE declined 12.68%, reflecting a significant negative market reaction. Argus tracked a trough of -11.5% from its starting point during tracking. Our momentum scanner triggered 85 alerts that day, indicating high trading interest and price volatility. This price movement removed approximately $329M from the company's valuation, bringing the market cap to $2.27B at that time. Trading volume was elevated at 2.2x the daily average, suggesting increased selling activity.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Class period start: August 3, 2023 Class period end: December 26, 2025 Share price pre-drop: $34.19 +5 more

8 metrics

Class period start August 3, 2023 Alleged securities fraud class period beginning

Class period end December 26, 2025 Alleged securities fraud class period ending

Share price pre-drop $34.19 Closing price on December 26, 2025 before UX143 disclosure reaction window

Share price post-drop $19.72 Closing price on December 29, 2025 after UX143 trial results

Three-day decline 42% Share price drop after UX143 Phase 3 Orbit and Cosmic results

Lead plaintiff deadline April 6, 2026 Deadline to seek appointment as lead plaintiff in class action

Toll-free contact 1-877-515-1850 Phone number for Kahn Swick & Foti regarding the lawsuit

Phase 3 designation Phase 3 Orbit and Cosmic studies for setrusumab (UX143) in osteogenesis imperfecta

Market Reality Check

Price: $22.72 Vol: Volume 7,186,994 is 2.89x...

high vol

$22.72 Last Close

Volume Volume 7,186,994 is 2.89x the 20-day average of 2,485,855, indicating elevated trading interest ahead of this legal update. high

Technical Shares trade below the 200-day MA at 31.34 and sit 55.65% under the 52-week high of 46.27, closer to the 52-week low at 18.41.

Peers on Argus

RARE is down 12.68% while key biotech peers show mixed, mostly smaller moves (e....

RARE is down 12.68% while key biotech peers show mixed, mostly smaller moves (e.g., TLX +1.55%, SLNO -3.8%, SRRK -2.98%), pointing to stock-specific pressure rather than a broad sector move.

Historical Context

5 past events · Latest: Feb 12 (Neutral)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Feb 12	Earnings and guidance	Neutral	-1.6%	Reported 2025 revenue growth, large net loss, and restructuring with 10% workforce cut.
Feb 05	Earnings call notice	Neutral	+3.8%	Announced timing and access details for Q4 and full‑year 2025 results call.
Feb 03	UX111 long‑term data	Positive	+0.2%	Released positive longer‑term UX111 data with sustained biomarker and functional benefits.
Jan 30	UX111 BLA resubmission	Positive	-0.8%	Resubmitted UX111 BLA to FDA with extended follow‑up and safety data under Priority Review.
Jan 23	Inducement equity grant	Neutral	+0.4%	Granted 16,355 RSUs to new non‑executive officers under Nasdaq inducement rule.

Pattern Detected

Recent RARE news, including UX111 updates and earnings, has produced relatively modest single-day moves, so today’s double‑digit decline on class action headlines stands out versus the typical reaction pattern.

Recent Company History

Over the past few months, Ultragenyx reported longer‑term UX111 gene therapy data and a BLA resubmission, alongside preliminary and then full 2025 financials showing $673 million in revenue but substantial losses and a restructuring with a 10% workforce reduction. Other items included an inducement equity grant and earnings‑related calls. Against this backdrop, today’s class action notice ties directly back to the December 2025 UX143 Phase 3 failure already disclosed.

Market Pulse Summary

The stock dropped -12.7% in the session following this news. The decline reflects renewed focus on l...

Analysis

The stock dropped -12.7% in the session following this news. The decline reflects renewed focus on litigation risk following UX143’s failed Phase 3 Orbit and Cosmic studies, which previously coincided with a 42% drop from $34.19 to $19.72. Historically, UX111 and earnings updates moved the stock only modestly, so a double‑digit slide fits a pattern where clearly negative, binary outcomes and legal issues have weighed more heavily than routine operational news.

Key Terms

class action, securities fraud, Phase 3, Phase III, +2 more

6 terms

class action regulatory

"notifies investors in Ultragenyx Pharmaceutical Inc. ("Ultragenyx" ) ... of a class action securities lawsuit."

A class action is a lawsuit where a group of people with similar complaints sue a company together instead of each person filing separately; think of it as a neighborhood banding together to take one case to court rather than everyone hiring separate lawyers. Investors care because class actions can lead to large settlements or judgments, damage a company’s reputation, drain cash reserves, and distract management — all of which can reduce a company’s stock value and affect future earnings.

securities fraud regulatory

"investors of Ultragenyx who were adversely affected by alleged securities fraud between August 3, 2023 and December 26, 2025."

Securities fraud is the illegal act of lying to or misleading investors about the true value or prospects of stocks, bonds or other traded financial instruments — for example by making false statements, hiding key facts, trading on secret information, or artificially moving prices. It matters to investors because it can cause sudden losses, distort fair market prices and undermine trust in markets; think of it as someone rigging a scoreboard so others place bets on the wrong team.

Phase 3 medical

"announced the "results from the Phase 3 Orbit and Cosmic studies for setrusumab (UX143)"

Phase 3 is the late-stage clinical testing step for a new drug or medical treatment, where the product is given to large groups of patients to confirm effectiveness, monitor side effects, and compare it to standard care. Successful Phase 3 results are often the final scientific hurdle before regulators decide on approval and market launch—like passing a final exam before graduation—and can sharply change a company's valuation and future revenue prospects.

Phase III medical

"both its Phase III Orbit and Cosmic studies failed to demonstrate that setrusumab"

A Phase III trial is the late-stage clinical study that tests whether a medical treatment works and is safe in a large group of patients, often comparing it to standard care. Think of it as a final dress rehearsal or full-scale road test before regulators decide on approval; positive or negative results strongly influence a drug maker’s chance to sell the treatment, future revenue, and investment risk.

statistically significant medical

"failed to demonstrate that setrusumab triggered a statistically significant reduction in annualized fracture rates"

"Statistically significant" means that a result or difference observed in data is unlikely to have occurred by chance alone, suggesting there is a real underlying effect. For investors, it indicates that the findings or patterns they see are likely meaningful and not just random noise, helping them make more informed decisions based on reliable information. Think of it as a pattern that is strong enough to stand out clearly from background randomness.

lead plaintiff regulatory

"you have until April 6, 2026 to request that the Court appoint you as lead plaintiff"

The lead plaintiff is the representative investor chosen to speak and act on behalf of a group of shareholders in a securities lawsuit. Think of them as the elected spokesperson for a neighborhood when everyone sues a landlord: they coordinate the legal case, make strategic decisions, and negotiate settlements, so their choices can shape outcomes and any recovery that reaches all affected investors. Investors care because the lead plaintiff’s resources and approach can influence the size and speed of any payout and the costs deducted from it.

AI-generated analysis. Not financial advice.

NEW YORK and NEW ORLEANS, Feb. 13, 2026 /PRNewswire/ -- Kahn Swick & Foti, LLC ("KSF") and KSF partner, former Attorney General of Louisiana, Charles C. Foti, Jr., notifies investors in Ultragenyx Pharmaceutical Inc. ("Ultragenyx" or the "Company") (NasdaqGS: RARE) of a class action securities lawsuit.

CLASS DEFINITION: The lawsuit seeks to recover losses on behalf of investors of Ultragenyx who were adversely affected by alleged securities fraud between August 3, 2023 and December 26, 2025. Follow the link below to get more information and be contacted by a member of our team:

https://www.ksfcounsel.com/cases/nasdaqgs-rare/

Ultragenyx investors should contact KSF Managing Partner Lewis Kahn toll-free at 1-877-515-1850 or via email (lewis.kahn@ksfcounsel.com), or visit https://www.ksfcounsel.com/cases/nasdaqgs-rare/ to learn more.

CASE DETAILS: On December 26, 2025, the Company announced the "results from the Phase 3 Orbit and Cosmic studies for setrusumab (UX143) in Osteogenesis Imperfecta" disclosing that both its Phase III Orbit and Cosmic studies failed to demonstrate that setrusumab triggered a statistically significant reduction in annualized fracture rates for patients with osteogenesis imperfecta, and, as a result the Company "is evaluating its planned operations and will promptly define and implement significant expense reductions." On this news, the price of Ultragenyx's shares fell approximately 42%, from $34.19 per share on December 26, 2025 to $19.72 per share on December 29, 2025.

The case is Steven Bailey v. Ultragenyx Pharmaceutical Inc., et al., No. 26-cv-01097.

WHAT TO DO? If you invested in Ultragenyx and suffered a loss during the relevant time frame, you have until April 6, 2026 to request that the Court appoint you as lead plaintiff; however, your ability to share in any recovery does not require that you serve as a lead plaintiff.

About Kahn Swick & Foti, LLC

KSF, whose partners include former Louisiana Attorney General Charles C. Foti, Jr., is one of the nation's premier boutique securities litigation law firms. This past year, KSF was ranked by SCAS among the top 10 firms nationally based upon total settlement value. KSF serves a variety of clients, including public and private institutional investors, and retail investors - in seeking recoveries for investment losses emanating from corporate fraud or malfeasance by publicly traded companies. KSF has offices in New York, Delaware, California, Louisiana, Chicago, and a representative office in Luxembourg.

TOP 10 Plaintiff Law Firms - According to ISS Securities Class Action Services

To learn more about KSF, you may visit www.ksfcounsel.com.

Contact:
Kahn Swick & Foti, LLC
Lewis Kahn, Managing Partner
lewis.kahn@ksfcounsel.com
1-877-515-1850
1100 Poydras St., Suite 960
New Orleans, LA 70163

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SOURCE Kahn Swick & Foti, LLC