Phase II trial of temsirolimus (CCI-779) in recurrent glioblastoma multiforme: a North Central Cancer Treatment Group Study.
BACKGROUND
Temsirolimus (CCI-779) is a small-molecule inhibitor of the mammalian target of rapamycin (mTOR) and represents a rational therapeutic target against glioblastoma multiforme (GBM).


METHODS
Recurrent GBM patients with < or = 1 chemotherapy regimen for progressive disease were eligible. Temsirolimus was administered in a 250-mg intravenous dose weekly.


RESULTS
Sixty-five patients were treated. The incidence of grade 3 or higher nonhematologic toxicity was 51%, and consisted mostly of hypercholesterolemia (11%), hypertriglyceridemia (8%), and hyperglycemia (8%). Grade 3 hematologic toxicity was observed in 11% of patients. Temsirolimus peak concentration (Cmax), and sirolimus Cmax and area under the concentration-time curve were decreased in patients receiving p450 enzyme-inducing anticonvulsants (EIACs) by 73%, 47%, and 50%, respectively, but were still within the therapeutic range of preclinical models. Twenty patients (36%) had evidence of improvement in neuroimaging, consisting of decrease in T2 signal abnormality +/- decrease in T1 gadolinium enhancement, on stable or reduced steroid doses. Progression-free survival at 6 months was 7.8% and median overall survival was 4.4 months. Median time to progression (TTP) for all patients was 2.3 months and was significantly longer for responders (5.4 months) versus nonresponders (1.9 months). Development of grade 2 or higher hyperlipidemia in the first two treatment cycles was associated with a higher percentage of radiographic response (71% v 31%; P = .04). Significant correlation was observed between radiographic improvement and high levels of phosphorylated p70s6 kinase in baseline tumor samples (P = .04).


CONCLUSIONS
Temsirolimus is well tolerated in recurrent GBM patients. Despite the effect of EIACs on temsirolimus metabolism, therapeutic levels were achieved. Radiographic improvement was observed in 36% of temsirolimus-treated patients, and was associated with significantly longer TTP. High levels of phosphorylated p70s6 kinase in baseline tumor samples appear to predict a patient population more likely to derive benefit from treatment. These findings should be validated in other studies of mTOR inhibitors.
Galanis
Evanthia
E
Mayo Clinic and Mayo Foundation, 200 First St SW, Rochester, MN 55905, USA. galanis.evanthia@mayo.edu
Buckner
Jan C
JC
Maurer
Matthew J
MJ
Kreisberg
Jeffrey I
JI
Ballman
Karla
K
Boni
J
J
Peralba
Josep M
JM
Jenkins
Robert B
RB
Dakhil
Shaker R
SR
Morton
Roscoe F
RF
Jaeckle
Kurt A
KA
Scheithauer
Bernd W
BW
Dancey
Janet
J
Hidalgo
Manuel
M
Walsh
Daniel J
DJ
D000328:Adult; D000368:Aged; D018906:Antineoplastic Agents, Alkylating / Q000009:adverse effects / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D018773:Genes, erbB-1 / Q000502:physiology; D005909:Glioblastoma / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D011494:Protein Kinases / Q000187:drug effects*; D016879:Salvage Therapy; D020123:Sirolimus / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D058570:TOR Serine-Threonine Kinases; D016896:Treatment Outcome; D025521:Tumor Suppressor Proteins / Q000235:genetics
D018906:Antineoplastic Agents, Alkylating; D047428:Protein Kinase Inhibitors; D025521:Tumor Suppressor Proteins; C401859:temsirolimus; D011494:Protein Kinases; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D020123:Sirolimus