ORLANDOAbout one third of "bad prognosis" refractory B-cell
chronic lymphocytic leukemia (B-CLL) patients are salvageable with alemtuzumab
(Campath-1H), according to a compassionate use study presented at the 43rd
Annual Meeting of the American Society of Hematology (abstract 1538).
Alemtuzumab is a humanized monoclonal antibody, specifically targeted at the
CD52 antigen, the most abundant antigen on normal and malignant lymphocytes,
said Kanti R. Rai, MD, of the Long Island Jewish Medical Center, New Hyde Park,
NY, and Albert Einstein College of Medicine, Bronx, NY. Alemtuzumab activates
the complement system and antibody-dependent cellular cytotoxicity, causing
In the prior pivotal clinical trial (Keating MJ et al: Blood 94[suppl
1]:705a, 1999) among 93 patients with CLL who had failed therapy with
fludarabine (Fludara), the alemtuzumab response rate had been 33%, Dr. Rai
said. "After that pivotal clinical trial, because alemtuzumab is not an
antibody that is simple to use, many oncologists wanted to have their own
experience with it before it became commercially available," he said.
All patients in the compassionate use study had failed fludarabine treatment
or had relapsed within 6 months after prior alemtuzumab treatment.
Patients were in WHO performance status 2 or less and had failed a median of
5 (range, 1 to 11) prior chemotherapy regimens. Median age was 62, and mean
time from initial CLL diagnosis was 5.7 years. Twenty-two patients had
discontinued prior regimens because of adverse events, and 26 because of
Patients (n = 136; 74% male) received alemtuzumab 3 mg by slow intravenous
infusion on day 1, followed by dose escalation (on days 2 through 5) to 10 mg
and eventually to 30 mg when tolerated. Following this, all patients received
alemtuzumab maintenance therapy at 30 mg, three times a week for a maximum of
Anti-infection prophylaxis with trimethoprim/sulfamethoxazole and
famciclovir (Famvir) was mandatory from day 8 to at least 2 months after the
last dose of alemtuzumab.