New York, May 20, 2026, 14:05 EDT
Immutep Ltd’s Nasdaq-listed American depositary receipts fell about 5% in Wednesday afternoon trading, lagging a strong biotech tape, as fresh investor-law notices kept attention on litigation tied to the collapse of its key lung-cancer trial. The ADRs, U.S.-traded receipts for a foreign company’s shares, recently traded at $0.4778 after touching $0.4606; the SPDR S&P Biotech ETF was up about 3.5%.
The timing matters because Immutep is now fighting on several fronts at once: a sub-$1 Nasdaq price, shareholder litigation notices and the need to rebuild confidence after the March discontinuation of TACTI-004, its Phase III study in first-line non-small cell lung cancer. Nasdaq says its regular U.S. stock-market session runs from 9:30 a.m. to 4 p.m. Eastern time.
The company said on April 30 that Nasdaq had warned it was not in compliance with the exchange’s $1 minimum bid-price rule. Immutep has until Oct. 26, 2026, to regain compliance, and the notice has no immediate effect on trading of its ADRs, the company said.
Late Tuesday, Rosen Law Firm said a securities class-action lawsuit had been filed on behalf of purchasers of Immutep ADRs between March 24, 2025, and March 12, 2026, with a July 6 deadline to seek appointment as lead plaintiff. A lead plaintiff is the investor representative who helps direct a class-action case.
Other law-firm notices in the past two days have focused on similar allegations that Immutep misled investors over the prospects of TACTI-004, the company’s trial of eftilagimod alfa, or efti. The allegations remain claims by plaintiffs’ firms; the notices cited did not establish liability.
Immutep said on March 13 that an independent data monitoring committee had recommended stopping TACTI-004 after a planned futility analysis, a scheduled review meant to judge whether a trial still has a reasonable chance of success. Chief Executive Marc Voigt said then he was “very disappointed and surprised” by the outcome. Immutep
The company’s April quarterly report sharpened the picture. Immutep said patients receiving efti with Merck’s Keytruda and chemotherapy underperformed the control arm, and that a root-cause review could extend into the third quarter of calendar 2026. It also reported A$110.6 million in cash, cash equivalents and term deposits at March 31, with a cash runway — the expected period current funds can last — into the first half of 2028, though wind-down costs and a US$10 million payment obligation to Dr. Reddy’s will reduce that balance. Dr. Reddy’s executive M.V. Ramana said the firms were focused on the “appropriate path forward.” Immutep
Immutep has tried to keep the broader efti story alive outside the failed lung-cancer study. On April 15, it said the U.S. Food and Drug Administration granted orphan drug designation for efti in soft tissue sarcoma, a rare-cancer status that can bring regulatory support and other incentives but is not an approval. Voigt said the designation could provide a “direct step forward” into a late-stage study. Immutep
The next scheduled clinical marker is at the American Society of Clinical Oncology meeting in Chicago, where Immutep said an efti poster will be presented on May 30. The company said the abstract will cover cumulative clinical and immune-response data from earlier studies, not TACTI-004, because immune data collection from that trial was not complete.
The competitive context is narrow but important. Bristol Myers Squibb’s Opdualag, a combination of nivolumab and relatlimab, was approved in 2022 as the first LAG-3-blocking antibody combination for unresectable or metastatic melanoma, showing that the LAG-3 pathway has drawn serious drug-industry interest. Immutep’s efti is different: it is designed to activate antigen-presenting immune cells through MHC Class II rather than block LAG-3.
Merck is also part of the story because Keytruda, its anti-PD-1 cancer drug, was the backbone therapy in TACTI-004. Anti-PD-1 drugs aim to help immune cells recognize and attack tumors, but combination strategies remain risky; a failed futility analysis can quickly reset investor assumptions about a development-stage biotech.
The downside case is plain. If Immutep’s review points to a problem that cannot be isolated to trial design, operations or patient mix, efti’s value in other cancers could come under fresh doubt. The company must also deal with the Nasdaq bid-price clock and the legal overhang while waiting for data that may not answer the hardest TACTI-004 questions soon.
