Phase-I/II radio-immunotherapy study with Iodine-131-labeled anti-CEA monoclonal antibody F6 F(ab')2 in patients with non-resectable liver metastases from colorectal cancer

Int J Cancer. 1998 Feb 9;75(4):615-9. doi: 10.1002/(sici)1097-0215(19980209)75:4<615::aid-ijc20>;2-6.


Experimental studies in nude mice with human colon-carcinoma grafts demonstrated the therapeutic efficiency of F(ab')2 fragments to carcinoembryonic antigen (CEA) labeled with a high dose of 131Iodine. A phase I/II study was designed to determine the maximum tolerated dose of 131I-labeled F(ab')2 fragments (131I-F(ab')2) from anti-CEA monoclonal antibody F6, its limiting organ toxicity and tumor uptake. Ten patients with non-resectable liver metastases from colorectal cancer (9 detected by CT scan and 1 by laparotomy) were treated with 131I-F(ab')2, doses ranging from 87 mCi to 300 mCi for the first 5 patients, with a constant 300-mCi dose for the last 5 patients. For all the patients, autologous bone marrow was harvested and stored before treatment. Circulating CEA ranged from 2 to 126 ng/ml. No severe adverse events were observed during or immediately following infusion of therapeutic doses. The 9 patients with radiologic evidence of liver metastases showed uptake of 131I-F(ab')2 in the metastases, as observed by single-photon-emission tomography. The only toxicity was hematologic, and no severe aplasia was observed when up to 250 mCi was infused. At the 300-mCi dose, 5 out of 6 patients presented grade-3 or -4 hematologic toxicity, with a nadir for neutrophils and thrombocytes ranging from 25 to 35 days after infusion. In these 5 cases, bone marrow was re-infused. No clinical complications were observed during aplasia. The tumor response could be evaluated in 9 out of 10 patients. One patient showed a partial response of one small liver metastasis (2 cm in diameter) and a stable evolution of the other metastases, 2 patients had stable disease, and 6 showed tumor progression at the time of evaluation (2 or 3 months after injection) by CT scan. This phase-I/II study demonstrated that a dose of 300 mCi of 131I-F(ab')2 from the anti-CEA Mab F6 is well tolerated with bone-marrow rescue, whereas a dose of 200 mCi can be infused without severe bone-marrow toxicity.

Publication types

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

MeSH terms

  • Adult
  • Antibodies, Monoclonal / pharmacokinetics
  • Antibodies, Monoclonal / therapeutic use
  • Carcinoembryonic Antigen / immunology*
  • Colorectal Neoplasms / therapy*
  • Dose-Response Relationship, Immunologic
  • Female
  • Hematopoiesis
  • Humans
  • Immunoglobulin Fab Fragments / therapeutic use
  • Iodine Radioisotopes / therapeutic use
  • Liver Neoplasms / secondary*
  • Liver Neoplasms / therapy
  • Male
  • Middle Aged
  • Radioimmunotherapy / adverse effects
  • Radioimmunotherapy / methods*


  • Antibodies, Monoclonal
  • Carcinoembryonic Antigen
  • Immunoglobulin Fab Fragments
  • Iodine Radioisotopes