Immutep announced that its Phase III TACTI‑004 trial of eftilagimod alfa (efti) in first‑line non‑small‑cell lung cancer was halted after an independent data monitoring committee recommended stopping for futility. The move forced an immediate wind‑down of the trial and triggered a near‑total selloff in Immutep’s stock. CEO Marc Voigt said the company was "very disappointed and surprised" and launched an internal review of the dataset to determine next steps. The TACTI‑004 readout was unexpected given prior positive signals for efti in earlier cohorts and raised questions about endpoint selection and translational rationale for LAG‑3 agonists versus other checkpoint strategies. Investors reacted swiftly, collapsing the company’s market value and increasing scrutiny of small immunotherapy developers' ability to de‑risk late‑stage programs. Analysts and company officials noted the result will likely force Immutep to reassess partnerships, financing needs, and the development pathway for its LAG‑3 platform. The episode underscores execution and signal‑validation risks associated with moving immune modulators into large, heterogeneous first‑line populations.