TY - JOUR
T1 - Phase I trial of recombinant immunotoxin RFB4(dsFv)-PE38 (BL22) in patients with B-cell malignancies
AU - Kreitman, Robert J.
AU - Squires, David R.
AU - Stetler-Stevenson, Maryalice
AU - Noel, Pierre
AU - FitzGerald, David J.P.
AU - Wilson, Wyndham H.
AU - Pastan, Ira
PY - 2005/9/20
Y1 - 2005/9/20
N2 - Purpose: To conduct a phase I trial of recombinant immunotoxin BL22, an anti-CD22 Fv fragment fused to truncated Pseudomonas exotoxin. Patients and Methods: Forty-six pretreated patients with CD22+ non-Hodgkin's lymphoma (NHL; n = 4), chronic lymphocytic leukemia (CLL; n = 11), and hairy cell leukemia (HCL; n = 31) received 265 cycles at 3 to 50 μg/Kg every other day × 3 doses. Results: BL22 was active in HCL, with 19 complete remissions (CRs; 61%) and six partial responses (PRs; 19%) in 31 patients. Of 19 CRs, 11 were achieved after one cycle and eight after two to 14 cycles. All 25 responders benefited clinically with one cycle. The CR rate was 86% in patients enrolled at > 40 μg/Kg every other day × 3, and 41% at lower doses (P = .011). The median duration for CR was 36 months (range, 5 to 66 months), and eight patients remain in CR at 45 months (range, 29 to 66 months). Lower but significant activity occurred in CLL. Neutralizing antibodies occurred in 11 (24%) of 46 patients (all HCL). A reversible hemolytic uremic syndrome requiring plasmapheresis was observed in one patient with NHL during cycle 1 and in four patients with HCL during cycle 2 or 3. The maximum-tolerated dose (MTD) evaluated at cycle 1 was 40 μg/Kg IV. QOD × 3. The most common toxicities at 30 to 50 μg/Kg every other day × 3 included hypoalbuminemia, transaminase elevations, fatigue, and edema. Conclusion: BL22 was well tolerated and highly effective in HCL, even after one cycle. Phase II testing is underway to define the efficacy with one cycle and to study safety when additional cycles are needed for optimal response.
AB - Purpose: To conduct a phase I trial of recombinant immunotoxin BL22, an anti-CD22 Fv fragment fused to truncated Pseudomonas exotoxin. Patients and Methods: Forty-six pretreated patients with CD22+ non-Hodgkin's lymphoma (NHL; n = 4), chronic lymphocytic leukemia (CLL; n = 11), and hairy cell leukemia (HCL; n = 31) received 265 cycles at 3 to 50 μg/Kg every other day × 3 doses. Results: BL22 was active in HCL, with 19 complete remissions (CRs; 61%) and six partial responses (PRs; 19%) in 31 patients. Of 19 CRs, 11 were achieved after one cycle and eight after two to 14 cycles. All 25 responders benefited clinically with one cycle. The CR rate was 86% in patients enrolled at > 40 μg/Kg every other day × 3, and 41% at lower doses (P = .011). The median duration for CR was 36 months (range, 5 to 66 months), and eight patients remain in CR at 45 months (range, 29 to 66 months). Lower but significant activity occurred in CLL. Neutralizing antibodies occurred in 11 (24%) of 46 patients (all HCL). A reversible hemolytic uremic syndrome requiring plasmapheresis was observed in one patient with NHL during cycle 1 and in four patients with HCL during cycle 2 or 3. The maximum-tolerated dose (MTD) evaluated at cycle 1 was 40 μg/Kg IV. QOD × 3. The most common toxicities at 30 to 50 μg/Kg every other day × 3 included hypoalbuminemia, transaminase elevations, fatigue, and edema. Conclusion: BL22 was well tolerated and highly effective in HCL, even after one cycle. Phase II testing is underway to define the efficacy with one cycle and to study safety when additional cycles are needed for optimal response.
UR - http://www.scopus.com/inward/record.url?scp=27244448693&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=27244448693&partnerID=8YFLogxK
U2 - 10.1200/JCO.2005.11.437
DO - 10.1200/JCO.2005.11.437
M3 - Article
C2 - 16061911
AN - SCOPUS:27244448693
SN - 0732-183X
VL - 23
SP - 6719
EP - 6729
JO - Journal of Clinical Oncology
JF - Journal of Clinical Oncology
IS - 27
ER -