Hyper-CVAD and high-dose methotrexate/cytarabine followed by stem-cell transplantation: an active regimen for aggressive mantle-cell lymphoma

Allogeneic hematopoietic transplantation for chronic lymphocytic leukemia and lymphoma: potential for nonablative preparative regimens

There is increasing interest in the use of allogeneic blood and marrow transplants for chronic lymphocytic leukemia (CLL) and lymphomas. Numerous studies indicate efficacy in patients with advanced disease and demonstrate existence of a potent graft-versus-malignancy effect against these disorders. Allogeneic transplantation is most effective in CLL and low-grade lymphomas, but precise indications and timing of allogeneic transplants in these indolent disorders are not well defined. Allotransplantation is an effective, potentially curative approach, albeit with substantial risks; it is indicated in selected categories of patients. Allogeneic transplants are also promising for mantle cell lymphoma. In large-cell lymphoma, relapses are reduced in allogeneic compared with autologous transplants, but the benefit of allotransplantation has been offset by increased risk of treatment-related complications, and its indications are controversial. A promising new strategy is the use of less toxic, nonmyeloablative preparative regimens to achieve engraftment and allow development of graft-versus-malignancy effects that can produce durable remission in selected categories of lymphoid malignancies.

Results of treatment with hyper-CVAD, a dose-intensive regimen, in adult acute lymphocytic leukemia

PURPOSE

To evaluate the efficacy and toxicity of Hyper-CVAD (fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone), a dose-intensive regimen, in adult acute lymphocytic leukemia (ALL).

PATIENTS AND METHODS

Adults with newly diagnosed ALL referred since 1992 were entered onto the study; treatment was initiated in 204 patients between 1992 and January 1998. No exclusions were made because of older age, poor performance status, organ dysfunction, or active infection. Median age was 39.5 years; 37% were at least 50 years old. Mature B-cell disease (Burkitt type) was present in 9%, T-cell disease in 17%. Leukocytosis of more than 30 x 10(9)/L was found in 26%, Philadelphia chromosome-positive disease in 16% (20% of patients with assessable metaphases), CNS leukemia at the time of diagnosis in 7%, and a mediastinal mass in 7%. Treatment consisted of four cycles of Hyper-CVAD alternating with four cycles of high-dose methotrexate (MTX) and cytarabine therapy, together with intrathecal CNS prophylaxis and supportive care with antibiotic prophylaxis and granulocyte colony-stimulating factor therapy. Maintenance in patients with nonmature B-cell ALL included 2 years of treatment with mercaptopurine, MTX, vincristine, and prednisone (POMP).

RESULTS

Overall, 185 patients (91%) achieved complete remission (CR) and 12 (6%) died during induction therapy. Estimated 5-year survival and 5-year CR rates were 39% and 38%, respectively. The incidence of CNS relapse was low (4%). Compared with 222 patients treated with vincristine, doxorubicin, and dexamethasone (VAD) regimens, our patients had a better CR rate (91% v 75%, P <.01) and CR rate after one course (74% v 55%, P <.01) and better survival (P <.01), and a smaller percentage had more than 5% day 14 blasts (34% v 48%, P =.01). Previous prognostic models remained predictive for outcome with Hyper-CVAD therapy.

CONCLUSION

Hyper-CVAD therapy is superior to our previous regimens and should be compared with established regimens in adult ALL.

Efficacy of autologous stem cell transplantation in mantle cell lymphoma: a 3-year follow-up study

This study was designed to evaluate the efficacy of therapeutic intensification with autologous stem cell transplantation (ASCT) for mantle cell lymphomas (MCL) in terms of response rate, duration of response, and event-free and overall survivals. Twenty-four patients with confirmed MCL responding to chemotherapy received a high-dose chemo-radiotherapy regimen followed by ASCT. Transplantation was performed during first-line therapy in nine cases, second-line in 13 cases and third-line in two cases. The source of hematopoietic stem cells was peripheral blood for 19 cases. At the time of ASCT, eight patients were in complete remission (33%). Seventeen of the 24 cases received an intensified regimen with TBI and seven received the BEAM or the BEAC regimen. After transplantation, 19 patients were in CR (79%). Nine of these were alive in continued CR at a median follow-up of 34 months, while seven relapsed at a median of 18 months. One patient died from Pneumocystis carinii interstitial pneumonitis and five patients developed secondary malignancies. With a median follow-up after transplantation of 34 months, the 3-year event-free survival was 55% and the 3-year overall survival was 68%. These results indicate that therapeutic intensification with ASCT might be an effective treatment for mantle cell lymphomas. Bone Marrow Transplantation (2000) 25, 251-256.

Allogeneic hematopoietic transplantation for mantle-cell lymphoma: molecular remissions and evidence of graft-versus-malignancy

BACKGROUND

The presence of a graft-versus-tumor effect has been well established for various hematological malignancies but not for mantle-cell lymphoma (MCL). We report preliminary results suggestive of a graft-versus-lymphoma effect in such patients post allogeneic hematopoietic transplantation.

PATIENTS AND METHODS

Sixteen patients with the diffuse type of MCL received allogeneic transplantation. Three had blastic features. Fifteen had an HLA-identical and one, a one HLA antigen mismatched sibling donor. Fifteen had stage IV disease. Eleven patients were previously treated, including one who failed prior autologous transplantation. Five patients were newly diagnosed and received transplantation after cytoreduction with three to eight courses of HYPER-CVAD (fractionated cyclophosphamide, doxorubicin, vincristine, dexamethasone) alternating with high-dose methotrexate and cytarabine.

RESULTS

Eleven patients received high-dose cyclophosphamide 120 mg/kg and total body irradiation (TBI) (12 Gy given in four daily fractions). Three patients were not eligible for TBI and received the BEAM regimen. Twelve (85.7%) achieved complete and two (14.3%) partial response. Two additional patients received a nonablative preparative regimen consisting of cisplatin, cytarabine and fludarabine. One failed to engraft and later relapsed. The other patient had progressive disease one month post transplant but later achieved complete remission now durable for 14+ months after developing graft-versus-host disease (GVHD). Residual lymphoma was assessed in seven patients by polymerase chain reaction assay (PCR) for bcl-1 or immunoglobulin gene rearrangement. All had detectable disease at the time of transplant. When tested within four months post transplant, four of these patients attained molecular remission. One of the three molecular non-responders converted to a negative PCR status seven months later and one fluctuates between positive and negative PCR fourteen months post transplant. Overall survival (OS) and failure-from-progression (FFP) at three years were both 55% (95% confidence interval (95% CI): 28%-83%). For patients with chemosensitive disease, FFP and OS at one year were both 90% (95% CI: 71%-100%) compared with 44% (95% CI: 1%-88%) (P = 0.04) for those who were refractory to conventional chemotherapy at the time of transplantation. There were six deaths. These were related to GVHD (three cases), infection (one case), multiorgan failure (one case), and graft failure (one case).

CONCLUSIONS

This report demonstrates the potential efficacy of allogeneic hematopoietic transplantation for MCL and provides the first evidence suggestive of graft-versus-malignancy in MCL. Data supportive of this concept include 1) achievement of remission concomitant with GVHD, 2) the conversion from a positive PCR status early after transplant to negative PCR status over time and 3) that the only relapse was in a patient who failed to engraft.

Molecular modelling of trimethoprim complexes of human wild-type and mutant dihydrofolate reductases: identification of two subsets of binding residues in the antifolate binding site

Computer-assisted molecular modelling was used to generate structures for the trimethoprim (TMP):NADPH:dihydrofolate reductase (DHFR) ternary complexes for human wild-type DHFR and for five DHFR mutants (L22R, L22F, F31S, F31W and Q35P). The mutants correspond to DHFR proteins that have been isolated from tissues exposed to chronic or high dose methotrexate (MTX) and show decreased sensitivity to antifolate inhibition. Analysis of the TMP:DHFR interactions suggest the presence of two subsets of TMP binding residues in the DHFR antifolate binding site. One subset of these residues (GLU30, PHE34, ILE60 and VAL115) are common to each DHFR complex studied and are referred to as core residues. The other TMP binding residues vary among the DHFR complexes studied and are referred to as noncore residues. The core residues exhibit a greater number of TMP contacts/residue and form more stable TMP interactions than noncore residues. Additionally, the core and noncore residues make contact with different regions of the TMP structure. Information presented here provides additional insight into the design of new agents for the improved inhibition of wild-type DHFR and the simultaneous inhibition of both wild-type and mutant DHFR molecules.

Treatment of follicular and other indolent lymphomas

The understanding of specific lymphoma entities continues to evolve. This is perhaps most clearly illustrated by developments concerning gastric lymphomas of mucosa-associated lymphoid tissue (MALT) origin, ranging from further evidence of the role played by Helicobacter pylori, to new information about the role of an apoptotic regulatory gene, bcl-10. Another area of productive research is the study of the mechanism of immune recognition and death signaling in follicular lymphomas. This should lead to refinements and improvements in an already very promising array of immunotherapeutic approaches, which currently ranges from vaccine development to allogeneic transplant strategies designed to induce a graft-versus-lymphoma effect. The clinical success of the chimeric anti-CD20 antibody, rituximab, leaves no doubt that biologic insights can lead to therapeutic advances. Researchers appear to be breaking free of the notion that alkylating agent therapy is the best option and the only viable treatment strategy for the indolent lymphomas. The current challenge is to apply new insights wisely.

Hodgkin's disease and non-Hodgkin's lymphoma

The development of new classification schemes and prognostic analyses for lymphomas has helped to identify patients at high risk for relapse who may benefit from intensification of primary therapy. Conventional salvage therapy for relapsed follicular or low-grade lymphomas now includes monoclonal antibody therapy. The combination of chemotherapy and monoclonal antibody therapy may improve outcomes for patients with advanced-stage aggressive non-Hodgkin's lymphomas. Confirmatory randomized trials are now in progress. Therapy for Hodgkin's disease continues to evolve toward the most efficacious programs, which also minimize the long-term probability of toxicity. The combination of high-dose chemotherapy and stem cell transplantation is probably the most effective therapy for patients with relapsed or refractory Hodgkin's disease.