Tango Therapeutics falls 12% despite strong pancreatic cancer data

What happened

• Tango released updated early-stage results on Friday, Oct 23, at the start of the ESMO cancer congress in Madrid. The trial pairs vopimetostat, its once-daily pill, with Revolution Medicines’ daraxonrasib (sold as Rasonque). It enrolls patients whose pancreatic tumors carry a RAS mutation and have lost a gene called MTAP, which happens in roughly 18–40% of pancreatic cancers (pharmaphorum).
• Tumors shrank in 18 of 22 patients (82%) who had already had one or two earlier treatments, most of them two. Eleven responses were confirmed by the Aug 20 data cutoff and the other seven afterward. Nine months in, 88% were alive without their cancer worsening.
• Tango plans a global Phase 3 trial against chemotherapy as a first treatment, starting in the first half of 2027, and will ask regulators about a faster path in second-line patients.
• The stock was down about 12% at $24.68 at 11:05 a.m. ET, after falling as much as 19%, erasing about $0.5 billion of market value. Revolution Medicines was little changed.

Why the market reacted this way

Our reading: the data were good, but much of the good news was already in the share price.

• Shares climbed about 27% in the four trading days before the release, and JPMorgan had put the stock on “positive catalyst watch” (Investing.com). After the data, Wedbush raised its price target to $45 from $39 and kept an Outperform rating (MT Newswires). Investors appeared to take profits once the numbers were out (IBTimes).
• In June, 11 of 12 patients (92%) had responded. With more patients and longer follow-up, the rate settled at 82%. That is still high, but the direction matters for a stock that had nearly quadrupled in a year.
• At the chosen dose, 40% of patients had severe (grade 3) treatment-related side effects, with none worse than grade 3, and a higher dose was not well tolerated. Pharmaphorum suggested safety may have weighed on the shares. For comparison, 43.6% of patients on Rasonque alone had grade 3 or higher treatment-related side effects in its Phase 3 trial.
• Expectations are higher now that Rasonque is approved: alone, it shrank tumors in about a third of previously treated patients, against about 11% with chemotherapy, in its Phase 3 trial. Tango’s own Phase 3 will test the combination against chemotherapy as a first treatment, so randomized proof is still to come.
• Phase 3 starts in 2027, and approval would come later. Tango also depends on Revolution Medicines to supply daraxonrasib for that trial, a risk its release flags.

Does this change Tango’s future?

What did NOT change

• The combination still looks highly active and durable in one of the hardest cancers to treat, and the Phase 3 design follows talks with the FDA.

What DID change

• Investors now face a long wait for randomized data, with an approved drug, Rasonque, setting expectations.

Our read

This looks like a sell-the-news reset after a strong run, not a verdict on the drug. The randomized Phase 3 trial is the real test.