Lost Money on Immutep Limited (IMMP)? Join Class Action Suit Seeking Recovery - Contact SueWallSt

Immutep's CEO, Chief Scientific Officer, and Chief Medical Officer Face Section 20(a) Control Person Claims After TACTI-004 Trial Collapse Cost Shareholders $2.28 Per Share

NEW YORK, May 21, 2026 /PRNewswire/ -- SueWallSt alerts investors in Immutep Limited (NASDAQ: IMMP) that three senior executives are named as individual defendants in a securities class action covering purchases between March 24, 2025 and March 12, 2026. Find out if you qualify to recover losses or contact Joseph E. Levi, Esq. at [email protected] or (888) SueWallSt.

Immutep ADRs fell from $2.76 to $0.48 per share on March 13, 2026, an 83% single-day decline of $2.28 per share. The Court has set July 6, 2026 as the deadline to apply for lead plaintiff appointment.

The Named Individual Defendants

The complaint identifies three officers who allegedly exercised control over Immutep's public statements and SEC filings throughout the Class Period:

• Marc Voigt, Executive Director and Chief Executive Officer, who oversaw all corporate communications and signed Company filings with the SEC
• Frédéric Triebel, Executive Director and Chief Scientific Officer, who directed efti's clinical development strategy and publicly vouched for TACTI-004's scientific foundation
• Stephan Winckels, Chief Medical Officer, who managed clinical trial operations and provided public commentary on investigator feedback and trial design

The action contends each defendant possessed the power and authority to control the contents of Immutep's SEC reports, press releases, and presentations to analysts and institutional investors.

Section 20(a) Control Person Framework

Section 20(a) of the Securities Exchange Act imposes liability on every person who directly or indirectly controls any person liable under Section 10(b). The complaint alleges that each Individual Defendant:

• Had access to material non-public information regarding TACTI-004's internal clinical data and interim analyses
• Was provided with copies of the Company's reports and press releases prior to or shortly after issuance
• Had the ability and opportunity to prevent the issuance of misleading statements or cause them to be corrected
• Knew that adverse facts had not been disclosed to the investing public

Sarbanes-Oxley Certification Obligations

As officers responsible for Immutep's SEC filings, the Individual Defendants bore personal certification obligations under Sections 302 and 906 of the Sarbanes-Oxley Act. These certifications require signing officers to attest that filings do not contain untrue statements of material fact or omit material facts necessary to make the statements not misleading. The lawsuit asserts these certifications were made while defendants allegedly concealed information that materially increased the risk of TACTI-004's failure.

Scienter Allegations

The complaint charges that the Individual Defendants acted with scienter, meaning they knew or were deliberately reckless in not knowing that their public statements were materially misleading. As pleaded, defendants had actual knowledge of or access to non-public information concerning interim efficacy data from the TACTI-004 trial, including the likelihood that the study would not meet its primary endpoints. Despite this alleged knowledge, they repeatedly told investors the trial exhibited "strong operational progress" and was "on track" for key milestones.

"Corporate officers have a duty to ensure their companies' public statements are accurate and complete. When executives certify SEC filings and make affirmative statements about clinical trial progress, they accept personal responsibility for the accuracy of those representations." -- Joseph E. Levi, Esq.

Speak with an attorney about recovering your IMMP losses or call (888) SueWallSt.

WHY SUEWALLST -- Ranked in ISS Securities Class Action Services' Top 50 Report for seven consecutive years, SueWallSt is a nationally recognized leader in shareholder rights litigation. With a team of over 70 professionals, the firm has recovered hundreds of millions of dollars for investors.

Frequently Asked Questions About the IMMP Lawsuit

Q: Who are the defendants named in the IMMP lawsuit? A: The complaint names Immutep Limited and individual defendants Marc Voigt (CEO), Frédéric Triebel (Chief Scientific Officer), and Stephan Winckels (Chief Medical Officer), each of whom signed SEC filings or made public statements during the Class Period.

Q: What is the IMMP lead plaintiff deadline? A: The deadline to apply for lead plaintiff appointment is July 6, 2026. This deadline applies only to investors seeking to serve as lead plaintiff. Class members who do not apply may still participate in any recovery without taking action before this date.

Q: What do IMMP investors need to do right now? A: Gather brokerage records including purchase dates, share quantities, and prices paid. Contact SueWallSt for a free, no-obligation evaluation at [email protected] or (888) SueWallSt. No immediate action is required to remain eligible as a class member.

Q: What if I already sold my IMMP shares -- can I still recover losses? A: Yes. Eligibility is based on when you purchased, not whether you still hold them. Investors who bought during the Class Period and sold at a loss may still participate.

Q: Do I need to go to court or give testimony? A: No. The overwhelming majority of class members never appear in court or give depositions. You submit a claim form to receive your portion of recovery.

Q: What does it cost me to participate? A: Nothing. Securities class actions are handled on a pure contingency basis. No upfront fees, no retainer, no out-of-pocket costs.

CONTACT:
SueWallSt
Joseph E. Levi, Esq.
Ed Korsinsky, Esq.
33 Whitehall Street, 27th Floor
New York, NY 10004
[email protected]
Tel: (888) SueWallSt
Fax: (212) 363-7171

SOURCE SueWallSt.com