Researchers at the University of California,
San Diego, (UCSD) Cancer Center report success inusing a new
technology to develop a sustained-release formulation of cytarabine
(ara-C). The new formulation, called DepoCyt, produced a
significantly better response rate than the standard ara-C
formulation in patients with lymphomatous meningitis. Results of the
open, multicenter, controlled study were reported at the 35th meeting
of the American Society of Clinical Oncology (ASCO).
Of the 27 study participants, 14 were treated with DepoCyt, and 13
with standard ara-C. Both groups received the drug via direct
injection into the cerebrospinal fluid surrounding the brain and
spinal cord. In the DepoCyt group, injections were administered once
every 2 weeks, and 71% of patients responded. The ara-C group
received injections twice a week and had a 15% response rate.
Patients were considered responders when, following 4 weeks of
treatment with the drug, no cancer cells remained in the
cerebrospinal fluid and there was no evidence of progression of
The study also demonstrated that patients treated with DepoCyt had
improved quality of life and tended to have a longer period during
which they were free from worsening neurologic signs and symptoms.
Effective Drug Concentrations Maintained in the Cerebrospinal Fluid
DepoCyt recently received FDA approval for use in patients with
lymphomatous meningitis. In its review, the FDA considered five
additional patients who had been treated recently, and applied a
different set of criteria for determining response. Nevertheless, the
FDAs analysis confirmed the large difference in response rates
(41% with DepoCyt vs 6% with standard ara-C).
We are pleased with the results of this trial, said
Stephen B. Howell, MD, professor of medicine at the UCSD School of
Medicine. We had expected the major benefit of the new
formulation to be that it makes treatment easier for the patient
because only one injection is required every 2 weeks. The results
show, however, that DepoCyt is also much more effective.
DepoCyt maintains effective concentrations of ara-C in the
cerebrospinal fluid for more than 2 weeks in most patients, whereas
injection of the standard formulation of ara-C provides effective
cerebrospinal fluid drug levels for only a matter of hours.