This is a phase 1a/1b, open-label, multicenter, dose-escalation and dose-expansion study evaluating the safety, tolerability, antitumor activity, pharmacokinetics, and pharmacodynamics of FXB0871 monotherapy in adults with selected locally advanced or metastatic solid tumors. In Part Ia, participants with selected solid tumors that have progressed after, are intolerant to, or are not suitable for standard therapy will receive FXB0871 in dose-escalation cohorts to determine the maximum tolerated dose and/or recommended phase 2 dose. In Part Ib, participants with PD-(L)1-resistant non-small cell lung cancer or hepatocellular carcinoma will receive FXB0871 in dose-expansion cohorts to further evaluate antitumor activity, safety, and dose optimization.
Signed informed consent.
Age ≥18 years.
Histologically confirmed selected locally advanced or metastatic solid tumor with progression on, intolerance to, or no suitable standard therapy.
ECOG performance status 0 or 1.
Systemic anti-cancer therapy, major surgery, or radical radiotherapy within 4 weeks before first dose.
Prior treatment with IL-2, IL-15, or IL-7.
Active autoimmune disease requiring systemic treatment or immunodeficiency.
Systemic corticosteroids (≥10 mg/day prednisone equivalent) or other immunosuppressive therapy within 28 days before first dose, with limited protocol-defined exceptions.