Tango's TNG260 trial closes enrollment as third completion-date push lands
The STK11-mutant lung cancer study has slipped its primary completion date three times since 2023, with the bar for a Phase 2 dose still resting on a five-patient subgroup signal.
Executive Summary
- Tango Therapeutics' TNG260 trial moved to Active, not recruiting on July 6, 2026, and its primary completion date shifted from January 1, 2026 to September 1, 2026, the second push since the trial started in 2023 Press ReleasePress ReleaseJul 6, 2026.
- Closing enrollment at the registry's target of 126 patients moves the study out of recruitment risk, but the repeated completion-date slippage means the readout timeline has proven unreliable twice already.
- The only public efficacy data point is a 5-patient subgroup with a 27-week median progression-free survival, flagged by the sponsor's own disclosure as small-n, subgroup-only, and lacking a comparator.
- TNG260 is one of just two active CoREST/LSD1-class assets in clinical development globally, giving the mechanism little external validation to lean on if the September readout disappoints.
- The enrollment closure is a procedural step forward, not a signal of clinical strength, and the trial's history of delay plus its thin dataset keep the setup fragile.
The status change
ClinicalTrials.gov recorded NCT05887492 moving from Recruiting to Active, not recruiting on July 6, 2026, alongside a shift in the primary completion date from January 1, 2026 to September 1, 2026 Press ReleasePress ReleaseJul 6, 2026. It is the trial's second completion-date change: the date first moved from January 2025 to January 2026 in February 2025. Enrollment has closed at the registry's anticipated target of 126 patients across 13 US sites. Protocol stability tools rate the trial's amendment pattern as Moderate, with 1.46 registry changes per year since 2023.
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
What the trial is testing
The Phase 1/2 study pairs TNG260, an oral small-molecule CoREST inhibitor (a protein complex tied to gene silencing), with an anti-PD-1 antibody in patients whose tumors carry an STK11 mutation, a genetic marker linked to poor checkpoint-inhibitor response. The Phase 1 primary endpoint is the maximum tolerated dose and recommended Phase 2 dose; the Phase 2 primary endpoint is antitumor activity measured by RECIST 1.1. The design has no comparator arm and is not randomized, which the sponsor itself does not label as registrational.
The evidence in hand
Tango's most recent public data, disclosed alongside third-quarter 2025 results on November 4, 2025, set the maximum tolerated dose at 80 mg once daily and reported a median progression-free survival of 27 weeks in a pre-specified subgroup of 5 STK11-mutant, KRAS-wild-type lung cancer patients. Tango's release characterized this as more than double the roughly 10-week standard-of-care benchmark, but the dossier flags the underlying data as small-n, subgroup-only, lacking a comparator arm, and immature. No results have been posted to ClinicalTrials.gov.
Regulatory and competitive frame
The FDA granted TNG260 Fast Track designation in April 2023 for previously treated advanced NSCLC with STK11 mutations, which allows rolling review and more frequent FDA meetings but does not itself predict approval. Within the CoREST/LSD1 inhibitor class, only one other asset, Jubilant Therapeutics' JBI-802, is in active clinical development, and it targets a different indication. The dossier's competitive-comparator set finds no eligible direct comparator for TNG260's target-indication pairing, leaving the mechanism without a same-target human precedent to benchmark against.
Model read
The AppliedXL model puts the probability the primary endpoint is met at 89.3%, trial completion at 86.4%, and regulatory approval at 81.9%, all as of the model's November 4, 2025 prediction timestamp. A separate clinical-significance score sits at 11.5%, reflecting how the model weighs monoclonal-antibody modality, small per-arm enrollment (63 patients per arm), and single-country, single-jurisdiction trial design as negative structural factors [AXL-MODEL]. The clinical-significance read rests mainly on operational-design and modality features rather than on mechanism-specific evidence, since target-biology and mechanistic-pharmacology drivers carry smaller and mixed weights, so it should be read as a structural signal rather than a verdict on TNG260's biology.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.