PRINCETON, NJ--Direct intratumor radioimmunotherapy (RAIT), with
multiple courses delivered via indwelling or removable catheters,
resulted in prolonged survival in patients with malignant glioma.
Observations in newly diagnosed patients suggests that this treatment
may have its greatest benefits as an adjuvant to primary surgical
excision, Dr. Agostino Arista said at the Fifth Conference on
Radioimmunodetection and Radioimmunotherapy of Cancer.
Patients with recurrent malignant glioma had improved survival
with the treatment, and those with minimal residual disease following
conventional primary therapy showed improved response rates. The
treatment was associated with no significant local or systemic
side effects, said Dr. Arista, of M. Buffalini Hospital, Cesena,
Italy, who presented the report for principal investigator P.
The investigators used two different iodine 131-labeled murine
monoclonal antibodies, BC-2 and BC-4, which react with tenascin,
an extracellular antigen associated exclusively with malignant
gliomas, Dr. Arista said.
Treatment was carried out in 38 patients after surgery for recurrent
glioma and in 14 patients following surgery and other conventional
treatments for newly diagnosed brain tumors. 131I was delivered
at doses escalating from 5 up to 69 mCi per cycle, and patients
received up to six treatments.
Of 48 evaluable patients, 12 experienced complete remissions.
Six patients had a partial remission, while nine had stable disease
and 21 progressed. The study did not include a randomized control
group, but median survival in the treated patients was considerably
longer than that reported for comparable patients who received
conventional therapy (18 months versus 12 months), Dr. Arista
The likelihood of a response was determined primarily by tumor
size, Dr. Arista continued. The response rate was about 40% in
the group as a whole, 54% in those with small or minimal lesions
following other therapy, and only 23% in those with bulky lesions.
Patients with newly diagnosed tumors had a somewhat greater rate
of response than those with recurrent disease.
Headaches, the only clinically apparent treatment side effect,
occurred in 13 patients and were transient in all cases. There
was no systemic, hematologic, hepatic, or renal toxicity.