A phase 2 clinical trial of deforolimus (AP23573, MK-8669), a novel mammalian target of rapamycin inhibitor, in patients with relapsed or refractory hematologic malignancies.
OBJECTIVE
Deforolimus (AP23573), a novel non-prodrug rapamycin analogue, inhibits the mammalian target of rapamycin, a downstream effector of the phosphatidylinositol 3-kinase/Akt and nutrient-sensing pathways. A phase 2 trial was conducted to determine the efficacy and safety of single-agent deforolimus in patients with relapsed or refractory hematologic malignancies.


METHODS
Eligible patients were assigned to one of five disease-specific, parallel cohorts and given 12.5 mg deforolimus as a 30-minute infusion once daily for 5 days every 2 weeks. A Simon two-stage design was used for each cohort. Safety, pharmacokinetics, pharmacodynamics, and antitumor response were assessed.


RESULTS
Fifty-five patients received deforolimus as follows: cohort 1 23 acute myelogenous leukemia, two myelodysplastic syndrome and one chronic myelogenous leukemia in nonlymphoid blast phase; cohort 2, one acute lymphocytic leukemia; cohort 3, nine agnogenic myeloid metaplasia; cohort 4, eight chronic lymphocytic leukemia; cohort 5, nine mantle cell lymphoma and two T-cell leukemia/lymphoma. Most patients were heavily pretreated. Of the 52 evaluable patients, partial responses were noted in five (10%), two of seven agnogenic myeloid metaplasia and three of nine mantle cell lymphoma. Hematologic improvement/stable disease was observed in 21 (40%). Common treatment-related adverse events, which were generally mild and reversible, were mouth sores, fatigue, nausea, and thrombocytopenia. Decreased levels of phosphorylated 4E-BP1 in 9 of 11 acute myelogenous leukemia/myelodysplastic syndrome patients after therapy showed mammalian target of rapamycin inhibition by deforolimus.


CONCLUSIONS
Deforolimus was well-tolerated in patients with heavily pretreated hematologic malignancies, and antitumor activity was observed. Further investigation of deforolimus alone and in combination with other therapeutic agents is warranted in patients with selected hematologic malignancies.
Rizzieri
David A
DA
Duke University Medical Center, Durham, North Carolina 27710, USA. rizzi003@mc.duke.edu
Feldman
Eric
E
Dipersio
John F
JF
Gabrail
Nashat
N
Stock
Wendy
W
Strair
Roger
R
Rivera
Victor M
VM
Albitar
Maher
M
Bedrosian
Camille L
CL
Giles
Francis J
FJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D019337:Hematologic Neoplasms / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020123:Sirolimus / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000627:therapeutic use; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
D000970:Antineoplastic Agents; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C515074:ridaforolimus; D020123:Sirolimus