Sometimes good data is not enough. Tango Therapeutics Inc. (TNGX) found that out on Friday, when it rolled out Phase 1/2 trial results for its investigational drug vopimetostat and the stock promptly dropped 10.65% to $24.95.
The data itself looked strong. Tango is testing vopimetostat, a PRMT5 inhibitor, in combination with Revolution Medicines Inc. (RVMD) RAS(ON) inhibitors daraxonrasib and zoldonrasib. The goal is to hit tumors with a specific genetic profile, and in targeted patient groups the combination produced marked tumor shrinkage.
Pancreatic Cancer Data: 82% Response Rate
In efficacy-evaluable patients with MTAP-deleted and RAS-mutant pancreatic ductal adenocarcinoma (PDAC), the vopimetostat-daraxonrasib combo generated an 82% objective response rate.
Tango evaluated 22 patients who had received prior treatments, primarily as third-line therapy. The regimen produced an 88% nine-month progression-free survival rate, while median progression-free survival remained unreached as of the August 20 data cutoff date. The combination also achieved a 100% disease control rate.
Safety looked manageable at dose level 1, which paired 200 mg of vopimetostat with 100 mg of daraxonrasib. Patients experienced no dose-limiting toxicities or adverse event withdrawals, although 20% required dose reductions.
In a smaller group of five non-small cell lung cancer patients, the combination yielded an 80% response rate with manageable low-grade symptoms.
This is not the first look at the program. Initial data shared in June showed that 92% of patients treated with the vopimetostat and daraxonrasib combination achieved an objective response, with the company planning to advance this combination into Phase 3 development for first-line treatment of MTAP-deleted pancreatic cancer.
Registrational Trial Plans And Regulatory Steps
Following recent discussions with the U.S. Food and Drug Administration (FDA), Tango aims to launch a global, randomized registrational study during the first half of 2027.
The pivotal trial will evaluate first-line MTAP-deleted PDAC patients, randomizing them to receive either the vopimetostat-daraxonrasib combination or standard-of-care chemotherapy.
The study will measure objective response rate and progression-free survival as dual primary endpoints, tracking overall survival as a key secondary metric. Tango also plans to discuss potential second-line approval pathways with regulatory authorities.
Additional Pipeline Progress With Zoldonrasib
Across an escalation cohort pairing vopimetostat with zoldonrasib in KRAS G12D-mutant pancreatic cancer, the therapy delivered a 54% objective response rate among 35 evaluable patients.
This arm produced one complete response and a 97% disease control rate, while maintaining favorable overall tolerability.
So why the selloff? Biotech stocks often move on expectations rather than absolute results, and Tango had already rallied hard into this update. The June data set a high bar, and Friday's numbers, while impressive, may have left some investors wanting more. The path to a 2027 registrational trial is also a long one, and the market is not always patient.
TNGX Price Action: Tango Therapeutics shares were down 10.65% at $24.95 at the time of publication on Friday, according to market data.
