Bortezomib, bendamustine, and rituximab in patients (pts) with relapsed (rel) or refractory (ref) follicular lymphoma (FL): Dose-finding results of the VERTICAL study

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Background: FL is an incurable indolent B-cell non-Hodgkin's lymphoma. Survival has improved in the past decade with the introduction of rituximab (Rituxan, R), but response decreases with repeated exposure. Bortezomib (Velcade, V) plus R was active and generally well tolerated in rel/ref FL [de Vos ASH 2006 Abs694], and bendamustine hydrochloride (Treanda, B) plus R has also shown activity in heavily pretreated FL [Robinson JCO 2008]. The current single-arm, multi-center study evaluates the efficacy and safety of VBR in pts with rel/ref FL. Here we report the safety of dose escalation of B in combination with VR. Methods: Pts with relapsed FL with ≥4 prior doses of R (no prior V or B), ≥1 measurable tumor mass, no active central nervous system lymphoma, KPS ≥50%, adequate hematologic, renal and hepatic function, and no peripheral neuropathy ≥G2 were eligible. Pts received five 35d cycles of V 1.6 mg/m2 (d1, 8, 15, 22), B 50, 70, or 90 mg/m2 (d1, 2) and R 375 mg/m2 (d1, 8, 15, 22, cycle 1; d1, cycles 2–5). B dose escalation continued based on cycle 1 dose-limiting toxicities (DLTs), defined as: treatment-related platelet count <25,000/mm3 for >7 days or any platelet count <10,000/mm3; G4 neutropenia for >7 days; any treatment-related ≥G3 non-hematologic toxicity other than inadequately treated nausea, vomiting, or diarrhea; or any toxicity resulting in >1 week treatment delay. Results: Sixteen pts (4 at B 50 mg/m2, 6 each at B 70 and 90 mg/m2) with a median of 3 prior therapies (range 1–13; 31% prior stem-cell transplantation) have been treated (15 evaluable for DLT); median age was 54.5 (44–80) yrs. There was one DLT at B 70 mg/m2 (severe rash; pt discontinued), and one DLT at 90 mg/m2 (G3 thrombocytopenia requiring cycle 2 d1 delay). Hematologic AEs were manageable and included 4 (25%) ≥G3 neutropenia and 1 (6%) G4 thrombocytopenia. Non-hematologic AEs ≥G3 in >1 pt were diarrhea (31%), fatigue (25%), vomiting (13%), and nausea (13%). Peripheral neuropathy was reported in 6 pts (38%; 1 G3). Evidence of antitumor activity has been observed. Conclusions: Enrollment is continuing in the phase II portion of the study with B 90 mg/m2, the highest planned dose.

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Phase I study of escalating doses of low-dose-rate, locoregional irradiation preceding Cytoxan-TBI for patients with chemotherapy-resistant non-Hodgkin's or Hodgkin's lymphoma

PURPOSE

In patients in whom bone marrow transplantation (BMT) fails, recurrence often occurs at sites known to have contained disease before initiating BMT. The purpose of this study was to find the maximal tolerable dose of locoregional irradiation (LRT) between 1000 and 2000 cGy that could be integrated with our Cytoxan-total body irradiation (TBI) BMT conditioning regimen in the treatment of lymphoma.

METHODS AND MATERIALS

Patients had Hodgkin's or non-Hodgkin's lymphoma in chemotherapy-refractory relapse. All patients received LRT to a maximum of three sets of fields encompassing either all current or all previously known sites of disease. Cytoxan-TBI consisted of cyclophosphamide 50 mg/kg daily for 4 days followed by TBI of 1200 cGy given in four fractions.

RESULTS

Twenty-one patients were enrolled. Radiation Therapy Oncology Group Grade 3 in-field acute toxicity was observed in 1 patient at each dose level up to 1500 cGy and in 3 of 6 patients receiving 2000 cGy. Clinically evident late toxicities were limited to hypothyroidism and one second malignancy occurring outside the LRT fields.

CONCLUSION

Low-dose-rate, LRT with concurrent Cytoxan-TBI before BMT has acceptable rates of in-field toxicity for doses up to 1500 cGy in five fractions. This regimen safely permits the use of a total combined radiation dose of up to 2700 cGy during 2 weeks, with encouraging in-field response rates in treatment-refractory patients.

Purging of autologous peripheral-blood stem cells using CD34 selection does not improve overall or progression-free survival after high-dose chemotherapy for multiple myeloma: results of a multicenter randomized controlled trial

PURPOSE

Although high-dose chemotherapy supported by autologous peripheral-blood progenitor-cell (PBPC) transplantation improves response rates and survival for patients with multiple myeloma, all patients eventually develop progressive disease after transplantation. It has been hypothesized that depletion of malignant plasma cells from autografts may improve outcome by reducing infused cells contributing to relapse.

PATIENTS AND METHODS

A randomized phase III study using the CEPRATE SC System (Cellpro, Bothell, WA) to enrich CD34(+) autograft cells and passively purge malignant plasma cells was completed in 190 myeloma patients randomized to receive an autograft of CD34-selected or unselected PBPCs.

RESULTS

After CD34 selection, tumor burden was reduced by 1.6 to 6.0 logs (median, 3.1), with 54% of CD34-enriched products having no detectable tumor. Median time to count recovery, number of transfusions, transplantation-related mortality, and days in hospital were equivalent between the two transplantation arms. With a median follow-up of 37 months, 33 patients (36%) in the selected and 34 patients (35%) in the unselected arm had died (P =.784). Median overall survival in the selected arm was reached at 50 months and is not reached at this time in the unselected arm (P =.78). Median disease-free survival was 100 versus 104 weeks (P =.82), with 67% of patients in the selected arm and 66% of patients in the unselected arm relapsing.

CONCLUSION

This phase III trial demonstrates that although CD34 selection significantly reduces myeloma cell contamination in PBPC collections, no improvement in disease-free or overall survival was achieved.

Immunotherapy with rituximab during peripheral blood stem cell transplantation for non-Hodgkin's lymphoma

Peripheral blood stem cell grafts from patients with lymphoma are often contaminated with neoplastic cells. Administration of a lymphoma-specific monoclonal antibody before collecting stem cells may be one way of reducing the contamination. Similarly, an antibody after transplantation at a time of minimal residual disease may increase the efficacy of the procedure. The objective of this study was to determine the safety of using rituximab as both an in vivo purging agent and a posttransplantation adjuvant. Eligible patients with lymphoma received 375 mg/m2 rituximab intravenously IV) on day 1, 2.5 g/m2 cyclophosphamide IV on day 4, and 10 microg/kg per day filgrastim starting on day 5 and continuing until completion of leukapheresis. Patients subsequently received a standard preparative regimen and then received 375 mg/m2 rituximab IV 7 days after platelet independence was achieved. Twenty-five patients (14 men, 11 women; median age, 51 years) were enrolled. Of the 25 patients, 23 received transplants after at least 2.0 x 10(6) CD34+ cells/kg were harvested. As determined with a sensitive polymerase chain reaction assay, 6 of 7 stem cell products tested were free of tumor contamination. All patients engrafted promptly, and the rituximab infusions were well tolerated. Transient neutropenia of uncertain etiology occurred in 6 patients a median of 99.5 days post-transplantation. An additional patient developed progressive pancytopenia. Rituximab used as an in vivo purging agent and adjuvant immunotherapy with peripheral blood stem cell transplantation for non-Hodgkin's lymphoma is a well-tolerated regimen. However, the ultimate determination of efficacy will require the results of ongoing studies.

Multicenter phase III trial to evaluate CD34(+) selected versus unselected autologous peripheral blood progenitor cell transplantation in multiple myeloma

High-dose chemotherapy followed by autologous transplantation has been shown to improve response rates and survival in multiple myeloma and other malignancies. However, autografts frequently contain detectable tumor cells. Enrichment for stem cells using anti-CD34 antibodies has been shown to reduce autograft tumor contamination in phase I/II studies. To more definitively assess the safety and efficacy of CD34 selection, a phase III study was completed in 131 multiple myeloma patients randomized to receive an autologous transplant with either CD34-selected or unselected peripheral blood progenitor cells after myeloablative therapy. Tumor contamination in the autografts was assessed by a quantitative polymerase chain reaction detection assay using patient-specific, complementarity-determining region (CDR) Ig gene primers before and after CD34 selection. A median 3.1 log reduction in contaminating tumor cells was achieved in the CD34 selected product using the CEPRATE SC System (CellPro, Inc, Bothell, WA). Successful neutrophil engraftment was achieved in all patients by day 15 and no significant between-arm difference for time to platelet engraftment occurred in patients who received an infused dose of at least 2.0 x 10(6) CD34(+) cells/kg. In conclusion, this phase III trial demonstrates that CD34-selection of peripheral blood progenitor cells significantly reduces tumor cell contamination yet provides safe and rapid hematologic recovery for patients receiving myeloablative therapy.

Highly purified CD34-positive cells reconstitute hematopoiesis

PURPOSE

The objective of this study was to characterize CD34+ cell grafts, obtained using a novel technique, from children undergoing autologous bone marrow transplantation (BMT) for cancer therapy. In particular, we wanted to determine if the CD34+ marrow cell grafts generated hematopoietic reconstitution, since a positive result would motivate further development and use of this methodology.

PATIENTS AND METHODS

This pilot feasibility clinical trial involved 13 patients < or = 25 years of age with advanced solid tumors, including seven children with neuroblastoma. Harvested bone marrow underwent immunomagnetic CD34+ selection.

RESULTS

In three of 13 enrolled patients, low purities of the CD34+ preparations disqualified the use of the CD34+ marrow grafts. Ten patients received myeloablative chemotherapy with etoposide, carboplatin, and cyclophosphamide, then were transplanted with CD34+ marrow grafts. In the 10 patients transplanted with CD34(+)-selected cells, the CD34+ cell purity (nucleated RBCs excluded) in the cell graft preparation was 91% total cell recovery from the starting light-density cells 2.2%, CD34+ cell recovery 38%, colony-forming unit-granulocyte-macrophage (CFU-GM) recovery 23%, and estimated tumor-cell depletion 2.6 logs (medians). The CD34+ marrow grafts administered to these patients contained a median of 2.3 x 10(6) nucleated cells, 1.4 x 10(6) CD34+ cells, and 1.3 x 10(4) CFU-GM per kilogram patient weight. Most patients experienced only the toxicities previously observed with this myeloblative chemotherapy regimen, although two unusual toxicities were observed. All 10 patients transplanted with CD34+ cell grafts engrafted.

CONCLUSION

The CD34+ purified grafts were enriched in stem/progenitor cells, with five of these 10 preparations containing > or = 94% CD34+ cells. Engraftment with CD34(+)-purified cell grafts as pure as 99% confirms that autologous CD34+ cells, alone, are sufficient to provide hematopoietic rescue for myeloablated patients. The best purification results were obtained on small marrow harvests from patients with neuroblastoma. The engraftment of highly purified CD34+ cells obtained by this technology and the antitumor effect of the transplant, by which two of 10 poor prognosis patients remain clinically free of tumor, have stimulated further clinical trials.

Tsetse and trypanosomiasis survey of Southern Darfur province, Sudan. II. Entomological aspects

Atsetse survey of Southern Darfur province, Sudan showed that the distribution of the only species present, Glossina morsitans submorsitans, had not appreciably altered over 10 years. Fly populations are most dense south of the Wadi Umbelasha but light infestations are found in the woodlands north of this riverine system to a latitude of about 10 degrees 15' N. Data are given on host availability which is thought to be the major factor determining tsetse distribution. The relative importance of tsetse and of tabanids as transmitters of bovine trypanosomiasis in the province is discussed. The evidence indicates that tsetse are very much more important and that cattle are most at risk of contracting infections during their dry season southerly migrations to the tsetse belts especially during their "Rushash" migration at first rains. Possibilities of tsetse control are discussed but in the short term trypanosomiasis control is most likely best achieved by chemical prophylaxis/therapy of cattle at risk.

Tsetse and trypanosomiasis survey of Southern Darfur Province, Sudan. I. Bovine trypanosomiasis

During a survey of Southern Darfur Province, Sudan blood samples from over 4,000 migratory cattle were analysed to determine levels of anaemia and trypanosome parasitaemia by buffy coat examination of microhaematocrit centrifuged samples. Levels of trypanosomal infections in the herds correlated well with their risk of exposure to tsetse being significantly lower at increasing distance from tsetse foci. Trypansoma vivax infections predominated in all herds, increasingly so with increasing distance from tsetse foci. Packed cell volume values could not be used to assist in trypanosome diagnosis at either individual or herd levels and the lack of correlation between anaemia and parasitaemia is suggested as evidence of a degree of trypanosomal tolerance in the Western Baggara cattle. Drug use and problems of drug resistance are discussed. Bovine trypanosomiasis is largely under control at present but requires continued surveillance (particularly of drug use) to prevent future problems as tsetse/cattle interactions increase.