Vascular and pharmacokinetic effects of EndoTAG-1 in patients with advanced cancer and liver metastasis

BACKGROUND

EndoTAG-1 (ET), a novel formulation of cationic liposomes carrying embedded paclitaxel (Taxol), shows antitumoral activity, targeting tumor endothelial cells in solid tumors. Patients with advanced metastatic cancer were evaluated investigating effects on pharmacokinetics and tumor vasculature using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and contrast-enhanced ultrasound (CEUS).

PATIENTS AND METHODS

The pharmacokinetic (PK) profile of ET (22 mg/m(2) i.v.) was evaluated after single and repeated doses. DCE-MRI and CEUS explored hepatic metastases before, during and after the 4-week treatment cycle. Angiogenic biomarkers were assessed. Tumor response was evaluated by modified RECIST.

RESULTS

The PK profile demonstrated slight accumulation of paclitaxel after repeated doses. DCE-MRI parameters K(trans) and/or iAUC(60) showed a trend to decrease. Changes of blood flow-dependent parameters of DCE-MRI and CEUS were well correlated. Angiogenic biomarkers revealed no clear trend. ET was generally well tolerated; common toxic effects were fatigue and hypersensitivity reactions. Nine (9 of 18) patients had stable disease after the first treatment cycle. Four patients without disease progression continued treatment.

CONCLUSIONS

This study including multiple pretreated patients with different metastatic cancer revealed individually distinctive hemodynamic alterations by DCE-MRI. The PK profiles of ET were similar as observed previously.

The human GRAF gene is fused to MLL in a unique t(5;11)(q31;q23) and both alleles are disrupted in three cases of myelodysplastic syndrome/acute myeloid leukemia with a deletion 5q

We have isolated the human GRAF gene (for GTPase regulator associated with the focal adhesion kinase pp125(FAK)). This gene was fused with MLL in a unique t(5;11)(q31;q23) that occurred in an infant with juvenile myelomonocytic leukemia. GRAF encodes a member of the Rho family of the GTPase-activating protein (GAP) family. On the protein level, it is 90% homologous to the recently described chicken GRAF gene that functions as a GAP of RhoA in vivo and is thus a critical component of the integrin signaling transduction pathway. The particular position of the human GRAF gene at 5q31 and the proposed antiproliferative and tumor suppressor properties of its avian homologue suggest that it also might be pathogenetically relevant for hematologic malignancies with deletions of 5q. To investigate this possibility, we sequenced 4-5 individual cDNA clones from 13 cases in which one allele of GRAF was deleted. We found point mutations within the GAP domain of the second GRAF allele in one patient. In two additional patients we found an insertion of 52 or 74 bp within the GRAF cDNA that generates a reading frame shift followed by a premature stop codon. GRAF maps outside the previously defined commonly deleted 5q31 region. Nevertheless, inactivation of both alleles in at least some cases suggests that deletions and mutations of the GRAF gene may be instrumental in the development and progression of hematopoeitic disorders with a del(5q).