A 63-year-old woman underwent living donor liver transplantation for hepatic metastases of an extragastrointestinal stromal tumor (EGIST) originating from the rectovaginal space. Due to a multifocal extrahepatic tumor recurrence, treatment with imatinib mesylate was started after extensive pharmacokinetic studies to rule out possible interactions with immunosuppressives. We performed several re- resections for EGIST recurrence thereafter. At the last follow-up, 17 years after primary tumor resection and 10 years after living donor liver transplantation, the patient is symptom-free under immunosuppressive and imatinib mesylate treatments with a 2-cm stable recurrent pararectal EGIST. To our knowledge, this is the only report published on a patient who underwent transplantation for hepatic EGIST metastases with a posttransplantation follow-up of 10 years and the first report on living donor liver transplantation for metastasized EGIST. This is the first description of pharmacokinetics of imatinib and its main active metabolite CGP74588 in a liver transplant recipient.

Einleitung: Für Pat. mit inoperablen Ca der Gallenwege gibt es keine etablierte palliative Zweitlinien-CT. Ziel dieser Studie war die Überprüfung der Verträglichkeit und der Wirksamkeit einer Therapie mit dem Tyrosinkinaseninhibitor Imatinib bei Pat. mit intra- (ICC) und extrahepatischen Cholangio-Ca (ECC) sowie Gallenblasen-Ca (GBC). Methodik: Prospektive, nicht-randomisierte, bizentrische, offene Phase II Studie. Einschlusskriterien: histologisch gesichertes Adenokarzinom, messbare Tumorläsion, Alter 18–75a, fehlendes Ansprechen auf vorangegangene CT, AZ nach WHO < 2. Die Imatinibdosis betrug 400mg/d für eine Woche, gefolgt von 600mg/d. Ein Restaging wurde nach 3 Mo. durchgeführt. Das Tumoransprechen wurde nach WHO-Standardkriterien bewertet. Bei Progress erfolgte ein Abbruch der Therapie. Ergebnisse: Insgesamt wurden 9 Pat. im Zeitraum 05/2006 bis 09/2008 eingeschlossen (3x ICC, 4x ECC, 2x GBC). Die Pharmakokinetikkurven lagen im Normbereich. Die beobachteten Nebenwirkungen waren: 9x AP-Anstieg (5x Grad I/II, 4x Grad III/IV), 9x Transaminasenerhöhung (8x Grad I/II, 1x Grad III/IV), 8x Bilirubin-Anstieg (2x Grad I/II, 6x Grad III/IV), 8x Anämie (7x Grad I/II, 1x Grad III/IV), 8x Übelkeit Grad I/II, 6x Erbrechen (5x Grad I/II, 1x Grad III/IV), 5x Kreatininerhöhung (3x Grad I/II, 2x Grad III/IV), 4x Fieber Grad I/II, 4x Gewichtsverlust Grad I/II und 3x Gewichtszunahme Grad I/II. Ansprechraten: 6x PD (1x bei rezidivierenden Therapiepausen), 3x Nicht-Erreichen der 3-Monatsgrenze (1x Therapiepause >3 Wo. bei Leberabszessen, 1x bakt. Cholangitis/Tumorprogress mit Todesfolge, 1x Tumorprogress mit Todesfolge). Das mediane Gesamtüberleben seit Therapiebeginn lag bei 4 Mo., das mediane Gesamtüberleben seit Tumordiagnose bei 26 Mo. (n=9), wobei bei Pat. 7 08/09 als letzter Berechnungszeitpunkt genutzt wurde. Schlussfolgerung: Imatinib als Monotherapie hat in der Zweitlinientherapie beim Gallenwegs-Ca bei mäßiger Verträglichkeit scheinbar keinen therapeutischen Effekt.

Einleitung: Für Patienten mit inoperablen Karzinomen der Gallenwege gibt es keine etablierte palliative Zweitlinienchemotherapie. Ziel dieser Studie war die Überprüfung der Verträglichkeit und der Wirksamkeit einer Therapie mit dem Tyrosinkinaseninhibitor Imatinib bei Patienten mit intra- (ICC) und extrahepatischen Cholangiokarzinomen (ECC) sowie Gallenblasenkarzinomen (GBC).

As low trough levels of mycophenolic acid (MPA) have been measured in recipients of allo-SCTs, we performed a pilot study targeting mycophenolate mofetil (MMF) doses according to the MPA area under the concentration (AUC) levels. Twenty-nine patients were transplanted from matched sibling (n=7) and unrelated donors (n=22). Tacrolimus was given orally from day −1 to achieve trough blood levels of 5–10 ng/ml. MMF was started on day 0 at 1500 mg intravenously b.i.d. AUC measurements of MPA by HPLC were scheduled on days 3, 7 and 11 after transplantation. The MMF dose was modified to achieve an MPA AUC of 35–60 μg/ml/h. With the respective adjustments 66 and 75% surpassed the lower AUC target on days 7 and 11, respectively. The cumulative incidence of grade III–IV acute GVHD was 28% (8/29). Eight out of 24 evaluable patients (33%) suffer from limited (n=3) or extensive (n=5) chronic GVHD. Overall, the results of this study suggest that targeting of MPA exposure is feasible early after transplantation. A simplified MMF targeting strategy based on MPA Cmax or C2h levels seems to be warranted in future trials involving more patients at later time points in the outpatient setting.

Neurotoxicity of cytarabine (AraC) is believed to be related to renal insufficiency. We examined the plasma pharmacokinetics of AraC and its deamination product uracil arabinoside (AraU) in four patients with AML and concomitant severe renal insufficiency after treatment with AraC. Additionally, in one of these patients the concentration of intracellular AraCTP, the active metabolite of AraC, was analysed. Patients 2 and 3 were treated with AraC 1.0 g/m2 infused for 3 h at 12-h intervals on days 1–4. Patient 1 received the same schedule of AraC with 0.5 g/m2 and patient 4 with 0.25 g/m2 AraC. Plasma concentrations of AraC, AraU and the intracellular concentration of AraCTP were analysed at different time points using HPLC. AraC pharmacokinetics in patients with severe renal insufficiency was comparable to patients with normal renal function. Peak plasma levels as well as intracellular AraCTP kinetics were also not significantly influenced by renal dysfunction. As expected from the high dose AraC pharmacokinetic parameters, the AraU serum levels accumulated during treatment. Under the conditions of renal impairment, AraU half-life was about 75 h and the AUC was about 12-fold higher than for patients with normal renal function. AraU could be the pathophysiologic cause for the known correlation between the incidence of neurotoxicity and renal insufficiency in high-dose AraC. To avoid AraU accumulation, intermittent hemodialysis during high-dose AraC treatment could be a suitable method considering the low protein-binding and low distribution volume of AraU.

An isocratic and sensitive HPLC assay was developed allowing the determination of the new anticancer drug nilotinib (AMN107) in human plasma, urine, culture medium and cell samples. After protein precipitation with perchloric acid, AMN107 underwent an online enrichment using a Zirchrom-PBD precolumn, was separated on a Macherey-Nagel C18-HD column and finally quantified by UV-detection at 258nm. The total run time is 25min. The assay demonstrates linearity within a concentration range of 0.005–5.0μg/ml in plasma (r2=0.9998) and 0.1–10.0μg/ml in urine (r2=0.9913). The intra-day precision expressed as coefficients of variation ranged depending on the spiked concentration between 1.27–9.23% in plasma and 1.77–3.29% in urine, respectively. The coefficients of variation of inter-day precision was lower than 10%. Limit of detection was 0.002μg/ml in plasma and 0.01μg/ml in urine. The described method is stable, simple, economic and is routinely used for in vivo and in vitro pharmacokinetic studies of AMN107.

OBJECTIVES:Recent data show that Imatinib mesylate (IM) also affects haematopoietic stem cells (HSC), T lymphocytes and dendritic cells that do not harbour constitutively active tyrosine kinases.MATERIALS AND METHODS:We evaluated possible effects of IM on human bone marrow-derived mesenchymal stem cells (MSC) in vitro.RESULTS:Screening the activity of 42 receptor tyrosine kinases revealed an exclusive inhibition of platelet-derived growth factor receptorbeta (PDGFRbeta). Analysis of downstream targets of PDGFRbeta demonstrated IM-mediated reduction of Akt and Erk1/2 phosphorylation. Culture of MSC with IM led to the reversible development of perinuclear multi-vesicular bodies. The proliferation and clonogenicity of MSC were significantly reduced compared to control cultures. IM favoured adipogenic differentiation of MSC whereas osteogenesis was suppressed. The functional deficits described led to a 50% reduction in the support of clonogenic haematopoietic stem cells, cultured for 1 month on a monolayer of MSC with IM.CONCLUSION:In summary, inhibition of PDGFRbeta and downstream Akt and Erk signalling by IM has a significant impact on proliferation and differentiation of human MSC in vitro.

Fludarabine is commonly used in combination with busulfan as part of conditioning regimens before allogeneic stem cell transplantation. So far, no data are available on busulfan–fludarabine drug interactions in transplant recipients. The pharmacokinetic (PK) properties of F-ara-A (9-β-D-arabinosyl-2-fluoradenine) before and after application of busulfan were prospectively investigated in 16 patients with hematological malignancies. The conditioning regimen consisted of intravenous fludarabine 30 mg/m2 over 30 min from day −6 to day −3, and oral busulfan given at 1 mg/kg every 6 h from day −5 to day −2. PK parameters of F-ara-A, derived from plasma and urine on day −6, −5, −4 and −3, were determined using high-performance liquid chromatography (HPLC). AUC, Cmax, t1/2, Cltotal and VSS were 21.9 μ Mh, 3.5 μ M, 13.0 h, 4.3 l/h/m2, 60.0 l/m2 on day −6 and 22.4 μ Mh, 3.5 μ M, 14.0 h, 4.7 l/h/m2, 69.0 l/m2 on day −5 to (−2), respectively. Clrenal and the urine-recovery were 4.8 l/h, 43.7% of the fludarabine dose on day −6 and 3.9 l/h, 44.2% of the fludarabine dose on day −5 to (−2), respectively. There were no changes in PK parameters of fludarabine given before and after intake of busulfan. This implies that a clinically relevant busulfan–fludarabine drug interaction is unlikely.

in a 200-patient, randomized, placebo-controlled trial of pancreatic cancer patients, that an EPA supplement was again ineffective.Overall, more than 650 cancer patients have participated in negative phase III studies with EPA.Although the selection of study end points can be challenging, as discussed by Dr Davis, one would think that if EPA were benefiting patients in some way, at least some suggestion of a comparative advantage would have been observed by now in one of these three major trials.Furthermore, preliminary phase II data from Barber et al 4 provided justification for the dose and manner of administration of the EPA supplement we tested, and presumably also for the supplement tested by Fearon et al.One might argue for additional preliminary evidence of efficacy before embarking on another major phase III trial with a higher dose or a different formulation of this agent.We do agree with Dr Davis that further study of the cancer anorexia/weight loss syndrome is indicated.Marked by increasing debility, shortened survival, and a poor quality of life, this syndrome is devastating for cancer patients.There is no question that it merits further clinical investigation.

4135 Background: While HCC is one of the most common cancers worldwide, no effective chemotherapy for advanced stages exists. Expression of PDGF receptor has been demonstrated on some hepatoma cell lines. Furthermore HCC may derive from hepatic stem cells that express c-kit. The aim of this trial was to evaluate the efficacy and safety of imatinib, a tyrosin kinase inhibitor of PDGFR and c-kit, in pts with advanced HCC, and of imatinib PKs in pts with impaired liver function. Methods: Pts with histologically proven advanced HCC, not eligible for surgery or locoregional treatment, with adequate organ function (bilirubin < 2x ULN, ALT/AST < 5x ULN, creatinine < 1.5x ULN, platelets > 70,000) were treated with imatinib 400 mg daily. After 2 weeks the dose was increased to 600 mg depending on toxicity. Immunohistochemical staining was performed for PDGFR and c-kit. Response was assessed by CT scans every 8 weeks. 74 plasma samples for PKs were assessed. Results: 17 pts, 15 evaluable for response were enrolled. 11 (65%) pts had liver cirrhosis, 5 (31%) were positive for anti-HCV, and 1 (6%) had hereditary hemochromatosis. Only 1 of 15 tumors assessed was positive for PDGFR and none of 14 positive for c-kit. Child-Pugh score was A and B in 13 (77%) and 4 (24%) pts and Okuda stage I and II in 8 (47%) and 9 (53%) pts, respectively. CLIP score was as follows: 1 (12%), 2 (18%), 3 (47%), 4 (24%). Grade 3–4 leukopenia occurred in 2 pts, of whom 1 had neutropenic fever. 1 episode of grade 3 diarrhea and 6 episodes of grade 3 edema occurred. There was no objective response and 5 (33%) pts had stable disease. Others failed treatment due to progression (60%, including 4 (27%) early deaths) and 1 (7%) early death not caused by HCC nor toxicity. Median time to treatment failure was 1.8 mos and 3.7 mos in pts with SD. In pts treated with 400 mg imatinib there were no significant differences in PKs (t½ 22.0 vs 26.6 h, AUC 32.0 vs 31.7 μg*h/ml, Cmax 1.20 vs 1.38 μg/ml, clearance 210 vs 221 ml/min) compared with CML pts. Conclusions: In this small group of pts with advanced, mostly PDGFR and c-kit negative HCC, imatinib showed no therapeutic effect. Imatinib PKs were not significantly influenced by impaired liver function as compared with CML pts. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Novartis

4210 Background: After having successfully treated a patient with HCC with imatinib (Anticancer Drugs, 2004;15:405) we treated twelve consecutive patients with histologically proven or clinically suspected HCC and Child A-cirrhosis. Methods: Patients were treated with imatinib at dosages from 200mg/d to 400mg/d. Routine chemical values and alpha-fetoprotein (AFP) levels were determined on a regular schedule and imatinib serum concentrations were analyzed by HPLC during the first weeks of treatment. Tumor size was monitored by abdominal ultrasound, or computer tomography. Results: One patient stopped imatinib after ten days due to diarrhea. The patient developed ascites and gastrointestinal bleeding from esophageal varices. Treatment was well tolerated by the remaining 11 patients within the first 6–8 weeks. Laboratory findings remained unchanged and imatinib serum concentrations were within the expected range indicating efficient excretion. However, imatinib metabolites were below the expected range. Eight of the 11 patients developed side effects (nausea, diarrhea, skin rush, fuzzy vision, spasms, edema) during the next 6 months. Treatment was discontinued, side effects disappeared and treatment was restarted at a reduced dosage of 200mg/d that was well tolerated. After 18 months of follow up, one patient has a complete response, two patients have stable disease, and 7 patients developed progressive disease. One patient dropped out of follow up at his own request. To date, 4 patients are alive (33%). Conclusions: Imatinib at a dosage of 200mg/d seems to be safe in patients with liver cirrhosis stage Child-Pugh A. The results suggest that a subgroup of patients with HCC may benefit from imatinib treatment. Efficacy of imatinib treatment in patients with HCC should be tested in a randomized trial. No significant financial relationships to disclose.

The pathophysiology of the myelodysplastic syndromes (MDS) involves disturbed regulation of angiogenesis, apoptosis, proliferation and differentiation as well as immune surveillance. Increasing data suggest that sirolimus might affect these pathways positively, thus being of possible therapeutic benefit in patients with this disease. Nineteen patients (n = 19) with a median age of 72 years (range 54-80 years) diagnosed with MDS received sirolimus orally with a target blood concentration of 3-12 ng/ml. Sirolimus was administered for a median of 3.7 months (range 0.3-11 months). Three patients [1 x refractory anaemia with excess blasts (RAEB)-2, 1 x RAEB-1, 1 x refractory cytopenia with multilineage dysplasia] showed either a major (1 x platelet, 1 x neutrophil) or a minor (1 x erythroid, 2 x platelet) haematological response according to International Working Group criteria. Major side-effects were hyperlipidaemia (n = 4), stomatitis (n = 3), thrombocytopenia (n = 2) and urinary tract infection (n = 1). These data suggest that sirolimus has activity in a subset of patients with more advanced MDS.

The use of pegfilgrastim (Neulasta™, Amgen Inc., Thousand Oaks, USA) in mobilization of CD34+ peripheral blood progenitor cells (PBPC) is promising because a continuously increased G-CSF level is suspected to exert a higher biological activity than pulsatile elevations after intermittent injections of unconjugated G-CSF. In clinical phase I/II trials we evaluated the agent both in combination with chemotherapy to mobilize autologous PBPC in 40 cancer patients and as growth factor treatment alone in a small pilot study with 25 allogeneic stem cell donors. The results were reported recently (Kroschinsky et al., Blood 2004; 104: 2922abstr.).

Objectives: No effective chemotherapy for advanced hepatocellular carcinoma (HCC) exists. Expression of the platelet-derived growth factor receptor (PDGFR) has been demonstrated in HCC, which may derive from hepatic stem cells that express c-kit. The aim of this trial was to evaluate imatinib, a tyrosine kinase inhibitor of PDGFR and c-kit, in patients with advanced HCC and impaired liver function. Patients and Methods: Patients were treated with 400–600 mg imatinib daily. Immunohistochemical staining was performed for PDGFR and c-kit. Response was assessed by CT scans every 8 weeks. For pharmacokinetics studies, 74 plasma samples were assessed. Results: Of the 17 patients enrolled in the study, 15 were evaluable for response. Only 1 tumor was positive for PDGFR and none was positive for c-kit. Grade 3/4 neutropenia occurred in 2 patients (1 had neutropenic fever). There was no objective response, and 5 (33%) patients had stable disease. Median time to treatment failure was 1.8 months in the whole study cohort and 3.7 months in the patients with stable disease. Patients treated with 400 mg imatinib did not significantly differ in pharmacokinetics from patients with chronic myelogenous leukemia (CML). Conclusion: In this small group of patients with advanced, mostly PDGFR- and c-kit-negative HCC, imatinib showed no therapeutic effect. In contrast to CML patients, the pharmacokinetics of imatinib were not significantly affected by impaired liver function.

A recent report by de Lima and coworkers showed that intravenous busulfan administered once daily over 4 days together with fludarabine can be used successfully as the preparative regimen before allogeneic hematopoietic cell transplantation from matched sibling and unrelated donors.1 Besides the positive outcome of their study, they showed that the once-daily infusion of busulfan was associated with low interdose variation of busulfan plasma pharmacokinetics (PK) and no accumulation over the 4 days of administration. Although interdosing variability was minimal, the daily area under the concentration–time curve (AUC) ranged between 2931 and 8271 mol min. Targeting of oral busulfan has been associated with favorable clinical results and reduced toxicity in patients receiving allogeneic transplantation for CML and MDS.2, 3 We therefore performed a pilot study in 10 patients with hematological malignancies combining 30 mg/m2 fludarabine i.v. (day -9 to -6) over 4 days with single doses of intravenous busulfan infused over 2 h on four consecutive days (-5 to -2). The starting dose of busulfan administered was 3.3 mg/kg adjusted to ideal body weight. We used a DMSO-based formulation which has been described in previous dose-finding studies.4 Blood samples were drawn every day during busulfan administration at time-points 0, 1, 2 (end of infusion), 3, 4 and 6 h. The busulfan plasma concentration was determined by HPLC.5 The dose of busulfan was targeted to achieve a concentration at steady state (Css) of 800–1000 ng/ml on the subsequent day. This target corresponded to AUC values of 4677–5847 mol min/l after daily single doses of busulfan, and was equivalent to the Css target used in a recent clinical study with fludarabine and oral busulfan.6 Figure 1 summarizes the doses of busulfan administered on each day and the corresponding plasma levels achieved. Three patients had a coefficient of variation of >25%, requiring more rigorous dose modifications. One of these patients had an elevated creatinin which dropped after infusion therapy. Minor dose modifications were required on the third and fourth days of busulfan application in all cases. Table 1 shows the PK parameters achieved with our approach. After transplantation of G-CSF-mobilized blood, GvHD prophylaxis consisted of tacrolimus 0.03 mg/kg and mycophenolate mofetil 2 1.5 g. Primary graft failure occurred in one patient only. He died after a second transplant from a mismatched sibling donor. Grade 4 hyperbilirubinemia associated with sepsis from Escherichia coli was observed in one patient who subsequently succumbed with multiorgan failure. No additional case of grade 4 extramedullary toxicity was observed. Relapse of high-risk acute myeloid leukemia occurred in two cases. Six patients are alive between 120 and 380 days after transplantation without signs of active disease. Our preliminary findings suggest that targeting of single-dose intravenous busulfan using a limited sampling strategy might allow to achieve a lower interpatient variability than reported by de Lima and coworkers.1 Of course the ideal target dose in this setting has not been defined yet. Prospective studies are warranted to prove whether the target level of once-daily intravenous busulfan, as described here, offers a meaningful clinical benefit compared to the standard split-dose application. We would like to thank Anett Haake and Ines Schulze for sample preparation and study coordination.