Phase 0 microdosing PET study using the human mini antibody F16SIP in head and neck cancer patients

J Nucl Med. 2013 Mar;54(3):397-401. doi: 10.2967/jnumed.112.111310. Epub 2013 Jan 18.


The aim of this microdosing phase 0 clinical study was to obtain initial information about pharmacokinetics, biodistribution, and specific tumor targeting of the antitenascin-C mini antibody F16SIP.

Methods: Two milligrams of F16SIP, labeled with 74 MBq of (124)I, were intravenously administered to patients with head and neck cancer (n = 4) scheduled for surgery 5-7 d later. Immuno-PET scans were acquired at 30 min and 24 h after injection. For pharmacokinetic analysis, blood samples were taken at different time points after infusion. Tissue uptake was extracted from whole-body PET scans. In addition, ex vivo radioactivity measurements of blood and of biopsies from the surgical specimens were performed.

Results: (124)I-F16SIP was well tolerated. Uptake was visible mainly in the liver, spleen, kidneys, and bone marrow and diminished over time. Tumor uptake increased over time, with all 4 tumors visible on 24-h PET images. The tumor-to-blood ratio was 7.7 ± 1.7 at the time of surgery. Pharmacokinetic analysis revealed good bioavailability of (124)I-F16SIP.

Conclusion: Performing a microdosing immuno-PET study appeared feasible and demonstrated adequate bioavailability and selective tumor targeting of (124)I-F16SIP.The results of this study justify further clinical exploration of (124)I-F16SIP-based therapies.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal* / pharmacokinetics
  • Carcinoma, Squamous Cell / blood supply
  • Carcinoma, Squamous Cell / diagnostic imaging*
  • Carcinoma, Squamous Cell / metabolism
  • Head and Neck Neoplasms / blood supply
  • Head and Neck Neoplasms / diagnostic imaging*
  • Head and Neck Neoplasms / metabolism
  • Humans
  • Iodine Radioisotopes / pharmacokinetics
  • Male
  • Middle Aged
  • Neovascularization, Pathologic / diagnostic imaging
  • Positron-Emission Tomography / methods*
  • Protein Structure, Tertiary
  • Radiation Dosage
  • Radiopharmaceuticals / pharmacokinetics
  • Tenascin / chemistry
  • Tenascin / immunology*
  • Tenascin / metabolism
  • Tissue Distribution


  • Antibodies, Monoclonal
  • Iodine Radioisotopes
  • Radiopharmaceuticals
  • Tenascin