Intracavitary injections of anti-cancer compound 131I-TM601 were well tolerated and improved overall survival in the treatment of recurrent malignant glioma, according to the presentation by Cambridge, Mass.-based TransMolecular at the 2009 joint meeting of the Society of Neuro-Oncology (SNO) and American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) section on tumors in New Orleans last week.
TM601 (chlorotoxin) is a 36 amino acid peptide with anti-tumor activity. The peptide binds specifically to the Annexin A2 receptor and can be radio-labeled for imaging and therapy.
Lead investigator John Fiveash, MD, associate professor of radiation oncology at the University of Alabama in Birmingham, said the primary purpose of the phase II trial, which was conducted at 20 clinical sites in the United States, was to compare the toxicity and overall survival of three versus six weekly intracavitary injections of 131I-TM601 in the treatment of recurrent high grade glioma.
In the study, eligible patients received prior radiotherapy and underwent tumor debulking surgery for recurrent high grade glioma. After a dose escalation phase which included 15 patients, 61 patients were randomized to receive either three or six weekly intracavitary injections of 131I-TM601 via a reservoir and catheter placed at the time of surgery.
Intracavitary 131I-TM601 was well tolerated and was safely administered at the maximum dose (40 mCi/0.8 mg x six weeks), according to the researchers. There was improved survival for 11.9 months with six doses and 9.1 months with three doses in an analysis that included all 69 patients who received at least one dose of 40 mCi/0.8 mg 131I-TM601.
They also reported that post-treatment tissue pathology showed progressive radiation necrosis in three patients.
Fiveash and colleagues concluded that 131I-TM601 improved survival and that giving up to six weekly doses was safe in the treatment of recurrent malignant glioma.
The study was sponsored by Cambridge, Mass.-based TransMolecular, developer of the 131I-TM601.