A Study of [225Ac]-FPI-1966 in Participants With Advanced Solid Tumours

A Phase 1/2 Study of [225Ac]-FPI-1966, [111In]-FPI-1967, and Vofatamab in Participants With FGFR3-expressing Advanced, Inoperable, Metastatic and/or Recurrent Solid Tumours

This first-in-human study evaluates safety, tolerability and distribution of [225Ac] FPI-1966, [111In]-FPI-1967, and vofatamab in patients with FGFR3-expressing solid tumors.

In phase 1, cohort 1, the potential impact of pre-dose administration of vofatamab on the dosimetry, PK, safety, and tolerability of [225Ac]-FPI-1966 and [111In]-FPI-1967 will be evaluated.

In later phase 1 cohorts, [225Ac]-FPI-1966 will be evaluated at ascending dose levels. Participants will receive [111In]-FPI-1967 during the imaging screening period to assess FGFR3 expression and to determine biodistribution and estimate radiation exposure to critical organs.

Once the recommended phase 2 dose (RP2D) or regimen is established and confirmed, three tumour-agnostic expansion cohorts may be initiated in parallel.

Key Inclusion Criteria:

• Signed ICF prior to initiation of any study-specific procedures
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Histologically and/or cytologically documented diagnosis of locally advanced, inoperable, or metastatic solid tumours
• Refractory to all standard treatments, or for whom standard treatment is not available, or tolerable, or is contraindicated, or the participant refuses standard therapy
• Measurable disease per RECIST v. 1.1
• Available tumour tissue (archival or fresh biopsy)
• Adequate bone marrow, heart, liver, and kidney function

Key Exclusion Criteria:

• Prior systemic radiopharmaceutical therapy within six months prior to the first dose of [111In]-FPI-1967
• Prior radiation therapy (RT) to bone marrow > 20 Gy
• RT within 30 days prior to the first dose of [111In]-FPI-1967
• Prior anti-cancer treatment (chemotherapy, immunotherapy, hormonal therapy, targeted therapy, or investigational agents) within a certain amount of time prior to administration of the first dose of [111In]-FPI-1967
• Concurrent serious co-morbidities that could limit participants' full participation and compliance