A large multicentric study of gemcitabine-based regimen in relapsed or refractory Hodgkin lymphoma (HL) patients (pts)

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Background: The aim of this study was to assess the efficacy and safety of gemcitabine-based regimen in heavily pretreated HL pts. Methods: Relapsed or refractory HL pts treated with gemcitabine were retrospectively reviewed. Gemcitabine was used as a single agent or administered in combination with vinorelbine, oxaliplatine, doxorubicine, vinblastine, rituximab, and/or corticosteroids. Results: Fifty-five pts treated in 9 departments of clinical hematology between January 1999 and August 2006 were included in the study. Initial characteristics before gemcitabine administration were: nodular sclerosis in 84%; sex ratio M/F 1.1; median age 29 years (range: 15–85 years); advanced stage 84%; extranodal sites were lung, bone, liver, soft tissues, and bone marrow in 68%, 31%, 13%, 21%, and 4%, respectively; Hasenclever index lower than 3 in 20/43 cases (47%). At the end of the first front-line therapy (chemotherapy ± radiotherapy), 19 pts (35%) were in complete response (CR) in whom 13 relapsed within one year, 5 were in partial response (PR), and 31 pts were primary refractory (56%). Median number of previous chemotherapeutic regimen was 3 (range 1–8), 39 pts (71%) have received radiotherapy (RT), and 34 pts (62%) one or two autologous/allogenic stem cell transplantations (A/ASCT). Twenty-nine pts received gemcitabine alone with a median initial dose per injection of 750 mg/m2 (range: 180–1250 mg/m2); Gemcitabine was administered at an initial dose per injection of 1000 mg/m2 (range: 500–1250) in combination with vinorelbine in 10 pts, oxaliplatine in 13 pts in whom 4 with rituximab, and with others drugs in 3 pts. In both cases, the median number of combined gemcitabine regimen injections was 6 (range: 1–27). Toxicity was mainly hematological (75% of pts developed bi- or pancytopenia) or infectious (13%). Among all included pts, 6 were in CR (11%) and 5 in PR with an overall response rate of 20%. Among the 6 CR, 5 pts received thereafter A/ASCT and 2 pts RT, with 2 persistent CR at 16 and 44 months. In univariate analysis, none prognostic factor for response to gemcitabine was identified. Conclusions: This study, which constitutes one of the most important series, showed a mild efficacy of gemcitabine-based regimen in heavily pretreated HL patients.

No significant financial relationships to disclose.

A phase I dose-finding and pharmacokinetic study of subcutaneous semisynthetic homoharringtonine (ssHHT) in patients with advanced acute myeloid leukaemia

To determine the maximum-tolerated dose (MTD), dose-limiting toxicities and pharmacokinetic of semisynthetic homoharringtonine (ssHHT), given as a twice daily subcutaneous (s.c.) injections for 9 days, in patients with advanced acute leukaemia, 18 patients with advanced acute myeloid leukaemia were included in this sequential Bayesian phase I dose-finding trial. A starting dose of 0.5 mg m⁻² day⁻¹ was explored with subsequent dose escalations of 1, 3, 5 and 6 mg m⁻² day⁻¹. Myelosuppression was constant. The MTD was estimated as the dose level of 5 mg m⁻² day⁻¹ for 9 consecutive days by s.c. route. Dose-limiting toxicities were hyperglycaemia with hyperosmolar coma at 3 mg m⁻², and (i) one anasarque and haematemesis, (ii) one life-threatening pulmonary aspergillosis, (iii) one skin rash and (iv) one scalp pain at dose level of 5 mg m⁻² day⁻¹. The mean half-life of ssHHT was 11.01±3.4 h, the volume of distribution at steady state was 2±1.4 l kg⁻¹ and the plasma clearance was 11.6±10.4 l h⁻¹. Eleven of the 12 patients with circulating leukaemic cells had blood blast clearance, two achieved complete remission and one with blast crisis of CMML returned in chronic phase. The recommended daily dose of ssHHT on the 9-day schedule is 5 mg m⁻² day⁻¹.

Valproic acid inhibits proliferation and induces apoptosis in acute myeloid leukemia cells expressing P-gp and MRP1

The multidrug resistance (MDR) phenotype, induced by the overexpression of several ABC transporters or by antiapoptotic mechanisms, has been identified as the major cause of drug resistance in the treatment of patients with acute myeloid leukemia (AML). In this study, we have shown that valproic acid (VPA) (a histone deacetylase inhibitor) can inhibit the proliferation of both P-glycoprotein (P-gp)- and MDR-associated protein 1 (MRP1)-positive and -negative cells. VPA also induced apoptosis of P-gp-positive cells. VPA induced apoptosis in K562 cells led to decrease in Flip (FLICE/caspase-8 inhibitory protein) expression with Flip cleavage, which could not be observed in HL60 cells. In HL60/MRP cell line, which proved to be resistant to apoptosis by VPA, we observed an abnormal expression of apoptotic regulatory proteins, overexpression of Bcl-2 and absence of Bax. Also, the Bcl-2 antagonist HA14-1 rapidly restored apoptosis in this cell line. Cotreatment with cytosine arabinoside induced very strong apoptosis in both K562/DOX and HL60/DNR cell lines. VPA also induced apoptosis in AML patient cells expressing P-gp and/or MRP1. Our findings show VPA as an interesting drug that should be tested in clinical trials for overcoming the MDR phenotype in AML patients.

Incidence and prognostic value of respiratory events in acute leukemia

Acute respiratory failure and infectious pneumonia are the major causes of death during induction chemotherapy of acute leukemia. However, the causes, incidence and prognostic value of all respiratory events (REs) occurring in this context have never been assessed prospectively. We recruited 65 consecutive patients with newly diagnosed acute leukemia into a 1-year prospective study (December 2000-November 2001) to evaluate the incidence and prognostic value of these events. REs were frequent: 38 were recorded in 30 patients. There was a significant relationship between REs and pre-existing respiratory disease and/or smoking. REs were caused by infection in 34% of cases, by an established cause other than infection in 42% and had an undetermined cause in 24%. Poor early outcome (death within 45 days of starting induction chemotherapy) in patients experiencing an RE was independently associated with a >25/min respiratory rate (P=0.003) and the nonachievement of complete remission (CR) (P<0.0001). Predictors of overall survival in the entire patient population were the absence of CR (P<0.0001), REs (P=0.02) and a > or =2 performance status (P=0.03). In conclusion, REs are frequent during induction chemotherapy of acute leukemia and represent an independent prognostic factor of poor outcome, regardless of their cause.