Phase I/II study of subcutaneous homoharringtonine in patients with chronic myeloid leukemia who have failed prior therapy.
BACKGROUND
Homoharringtonine (HHT) is a cephalotaxus alkaloid that inhibits the synthesis of proteins leading to apoptosis. Intravenous HHT has demonstrated activity in patients with chronic myeloid leukemia (CML) after failure with interferon.


METHODS
A Phase I study was completed of subcutaneous (s.c.) HHT in patients with CML in accelerated or blast phases and demonstrated efficacy and good tolerance at the same doses used by intravenous (i.v.) administration. The maximal tolerated dose (MTD) was 1.25 mg/m(2) s.c. twice daily. The cohort was then expanded to treated at the MTD to include patients in late chronic phase CML after imatinib failure. Therapy consisted of an i.v. loading dose of HHT 2.5 mg/m(2) over 24 hours, followed by 1.25 mg/m(2) s.c. twice daily for 14 days every 28 days until remission, then for 7 days every 28 days. Six patients (median age, 53 years) who had failed imatinib were treated and 5 were evaluable. Patients received a median of 4.5 courses of s.c. HHT.


RESULTS
Complete hematologic remission was obtained in all 5 evaluable patients and 3 had cytogenetic (CG) responses: 1 complete and 2 minor. The 2 patients with BCR-ABL kinase domain mutations at the start of therapy with HHT had a CG response and in both instances the mutations became undetectable. All patients developed myelosuppression and 3 had their HHT dose reduced due to prolonged neutropenia. Nonhematologic toxicity was mild and manageable.


CONCLUSIONS
Subcutaneous HHT is well tolerated and may have clinical activity in patients with CML after imatinib failure.
Quintás-Cardama
Alfonso
A
Department of Leukemia, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Kantarjian
Hagop
H
Garcia-Manero
Guillermo
G
O'Brien
Susan
S
Faderl
Stefan
S
Estrov
Zeev
Z
Giles
Francis
F
Murgo
Anthony
A
Ladie
Nakia
N
Verstovsek
Srdan
S
Cortes
Jorge
J
D000328:Adult; D000368:Aged; D000740:Anemia / Q000139:chemically induced; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D001549:Benzamides; D001752:Blast Crisis / Q000188:drug therapy; D003967:Diarrhea / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005221:Fatigue / Q000139:chemically induced; D005260:Female; D006248:Harringtonines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000077863:Homoharringtonine; D006801:Humans; D000068877:Imatinib Mesylate; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000139:chemically induced; D010879:Piperazines / Q000627:therapeutic use; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011743:Pyrimidines / Q000627:therapeutic use; D017211:Treatment Failure; D016896:Treatment Outcome
D000972:Antineoplastic Agents, Phytogenic; D001549:Benzamides; D006248:Harringtonines; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000077863:Homoharringtonine; D000068877:Imatinib Mesylate