Xilio begins Phase 1/2 testing of XTX501 in metastatic lung cancer

Xilio Therapeutics reported on October 26, 2026 that it had dosed the first participant in a Phase 1/2 study of XTX501. The bispecific therapy combines PD-1 blockade with masked IL-2 and is being tested in metastatic non-small cell lung cancer after prior anti-PD(L)-1 treatment. Xilio expects initial Phase 1 data in Q4 2027, while the U.S. multicenter trial evaluates safety and tolerability.

The trial start gives investors a defined development milestone and a stated Q4 2027 timeframe for initial data. The materials report no clinical results from the study yet.

  • 1Xilio has started dosing in a Phase 1/2 clinical study of XTX501 for metastatic non-small cell lung cancer.
  • 2The company expects initial Phase 1 data in Q4 2027.
  • 3The U.S. study is multicenter and open-label and is assessing XTX501 as a monotherapy in metastatic non-small cell lung cancer and select advanced solid tumors.
  • 4The trial is evaluating safety and tolerability in patients who previously received anti-PD(L)-1 therapy.

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