Contribution of chemotherapy mobilization to disease control in multiple myeloma treated with autologous hematopoietic cell transplantation.

In patients with multiple myeloma (MM) undergoing autologous hematopoietic cell transplantation (auto-HCT), peripheral blood progenitor cells may be collected following mobilization with growth factor alone (GF) or cytotoxic chemotherapy plus GF (CC+GF). It is uncertain whether the method of mobilization affects post-transplant outcomes. We compared these mobilization strategies in a retrospective analysis of 968 patients with MM from the Center for International Blood and Marrow Transplant Research database who received an auto-HCT in the US and Canada between 2007 and 2012. The kinetics of neutrophil engraftment (⩾0.5 × 10(9)/L) was similar between groups (13 vs 13 days, P=0.69) while platelet engraftment (⩾20 × 10(9)/L) was slightly faster with CC+GF (19 vs 18 days, P=0.006). Adjusted 3-year PFS was 43% (95% confidence interval (CI) 38-48) in GF and 40% (95% CI 35-45) in CC+GF, P=0.33. Adjusted 3-year OS was 82% (95% CI 78-86) vs 80% (95% CI 75-84), P=0.43 and adjusted 5-year OS was 62% (95% CI 54-68) vs 60% (95% CI 52-67), P=0.76, for GF and CC+GF, respectively. We conclude that MM patients undergoing auto-HCT have similar outcomes irrespective of the method of mobilization and found no evidence that the addition of chemotherapy to mobilization contributes to disease control.

The farnesyl transferase inhibitor, tipifarnib, is a potent inhibitor of the MDR1 gene product, P-glycoprotein, and demonstrates significant cytotoxic synergism against human leukemia cell lines.

Farnesyl transferase inhibitors (FTIs) target signal-transduction pathways responsible for the proliferation and survival of hematologic malignancies, including acute myelogenous leukemias (AML). Lonafarnib has been shown to be a potent inhibitor of Pgp-mediated drug efflux. On the basis of these findings, we examined the Pgp-inhibitory properties of tipifarnib and assessed its activity when combined with anthracyclines. The effects of tipifarnib on cell proliferation, induction of apoptosis and inhibition of Pgp-mediated anthracycline efflux were analyzed in two human leukemia cell lines overexpressing Pgp (CCRF-CEM and KG1a). Measurement of residual daunorubicin (DNR)-mediated fluorescence after incubation with DNR and tipifarnib demonstrated that tipifarnib significantly inhibited DNR efflux in CCRF-CEM with an IC(50) value less than 0.5 microM. Proliferation and apoptosis assays after exposure to DNR in the presence or absence of tipifarnib demonstrated synergistic inhibition of cellular proliferation, and induction of apoptosis with the combination of tipifarnib and DNR. Similar data was obtained with an enantiomer of tipifarnib that possesses no FTI activity. Incubation with tipifarnib and DNR did not interfere with inhibition of the post-translational processing of HDJ-2. These data suggest that tipifarnib possesses Pgp-inhibitory activity in addition to its FTI activity. In high risk and refractory patients these properties may be exploited as a dual targeting mechanism in the therapy of AML.

Classic Kaposi's sarcoma associated with human herpesvirus 8 infection in a 13-year-old male: a case report.

PURPOSE: Classic Kaposi's sarcoma (KS) is rare in children. Although its etiology is not fully understood, human herpesvirus 8 (HHV-8) is present in the angiogenic lesions. We report an HIV-negative, 13-year-old patient of Sicilian descent with HHV-8-associated classic KS to facilitate the diagnosis and treatment of this entity in children. EXPERIMENTAL DESIGN: DNA was extracted from the skin specimen of the patient and analyzed via PCR assay and Southern blot hybridization for HHV-8 DNA. The amplified HHV-8 DNA was cloned, sequenced, and compared with the prototype HHV-8-KS330/BAM. RESULTS: The patient presented with purpuric lesions on the distal lower extremities and the tip of his nose, associated with thrombocytopenia and leukopenia, suggesting an immune-mediated cytopenia. While on prednisone, he developed marked vascular proliferation in the groins. Biopsy of the skin lesions showed KS, and HHV-8 was detected in the tissues by PCR. Sequence analysis of the amplified DNA was homologous to the prototype HHV-8-KS330/BAM. His HHV-8 strain was the A subgroup, the type associated with Mediterranean classic KS. Stopping prednisone and treatment with IFN-alpha and IgG resulted in regression of the groin lesions. CONCLUSIONS: This report emphasizes the importance of recognizing classic KS in children and avoiding immunosuppressive therapies in indolent classic KS. The diagnostic and therapeutic strategies were effective and well tolerated.