Approaches to aggressive B-cell lymphomas in less fit patients

Treating unfit patients with aggressive B-cell lymphoma poses the dilemma of balancing potential cure while minimizing toxicity because of frailty and comorbidities. Age greater than 80 years and common comorbidities such as cardiovascular disease and poorly controlled diabetes mellitus often preclude the use of full-dose anthracyclines and steroids, the backbones of standard regimens for aggressive B-cell lymphomas. Assessing patient fitness remains subjective, with no consensus on best practice or how to integrate assessment tools into decision making. Incorporation of prephase steroids for all unfit patients may markedly improve performance status with consideration of standard dose therapy, especially in patients less than age 80. Although randomized studies are lacking, current data suggest patients age ≥ 80 years are considered unfit a priori and should receive dose-reduced anthracycline regimens or anthracycline-free regimens. Severe toxicity is highest after the first cycle of chemotherapy. Dose reductions for cycle 1 in unfit patients with plans to escalate as tolerated is often an effective strategy. Unfit patients often benefit from comanagement with gerontologists, cardio-oncologists, and endocrinologists depending on age and the nature of comorbidities. Palliative therapy for patients with newly diagnosed aggressive B-cell lymphoma results in median survivals of less than 3 months, and in general, should only be considered in patients with untreatable comorbidities such as advanced dementia or refractory metastatic solid tumors. Incorporating new, potentially less toxic agents such as novel antibodies, antibody-drug conjugates, and bispecific antibodies into first-line therapy is an exciting future direction with potential for substantial benefit in less fit patients.

Disparities in the early adoption of chemoimmunotherapy for diffuse large B-cell lymphoma in the United States

BACKGROUND

Since the 1970s, CHOP chemotherapy has been the standard treatment for patients with diffuse large B-cell lymphoma (DLBCL). In 2002, randomized trials changed this standard by showing that adding rituximab immunotherapy to CHOP improved survival. However, how these results influenced chemoimmunotherapy adoption in clinical practice remains unclear.

METHODS

Using the National Cancer Database to compare chemoimmunotherapy use with chemotherapy alone, we collected data on demographics, stage, health insurance, area-level socioeconomic status (SES), facility characteristics, and type of treatment for DLBCL patients diagnosed in the United States 2001-2004. Multivariable log binomial models examined associations between race, insurance, and treatment allocation, adjusting for covariates.

RESULTS

Among 38,002 patients with DLBCL, 27% received chemoimmunotherapy and 50% chemotherapy alone. Patients who had localized disease, were diagnosed in 2001 or who were black, uninsured/Medicaid insured, or lower SES were less likely to receive any form of chemotherapy (all P < 0.0001). Patients who were diagnosed in 2001 or who were black [relative risk (RR), 0.83; 95% confidence interval (CI), 0.78-0.89], >60 years (RR, 0.94; 95% CI, 0.90-0.98), or had localized disease (RR, 0.89; 95% CI, 0.86-0.92) were less likely to receive chemoimmunotherapy. Receiving treatment at high DLBCL volume teaching/research facilities was associated with the greatest likelihood of chemoimmunotherapy (RR, 1.69; 95% CI, 1.52-1.89).

CONCLUSIONS

Black DLBCL patients were less likely to receive chemotherapy or chemoimmunotherapy during this period.

IMPACT

This large national cohort study shows disparities in the diffusion of chemoimmunotherapy for DLBCL. Improving DLBCL outcomes will require efforts to extend access to proven advances in therapy to all segments of the population.

Rituximab therapy in malignant lymphoma

Rituximab is the first monoclonal antibody to have been registered for the treatment of B-cell lymphomas. Randomized studies have demonstrated its activity in follicular lymphoma (FL), mantle cell lymphoma and diffuse large B-cell lymphoma (DLBCL) in untreated or relapsing patients. Non-comparative studies have shown an activity in all other lymphomas. Because of its high activity and low toxicity ratio, rituximab has transformed the outcome of patients with B-cell lymphoma. A combination of rituximab plus chemotherapy, rituximab+cyclophosphamide+doxorubicin+vincristine+prednisolone (R-CHOP), has the highest efficacy ever described with any chemotherapy in DLBCL and FL. Some patients are refractory to rituximab but the precise mechanisms of this refractoriness are not understood.

Multicenter phase II trial of immunotherapy with the humanized anti-CD22 antibody, epratuzumab, in combination with rituximab, in refractory or recurrent non-Hodgkin's lymphoma

PURPOSE

A multicenter, single-arm study examining efficacy and toxicity of epratuzumab combined with rituximab was conducted in patients with recurrent or refractory non-Hodgkin's lymphoma.

PATIENTS AND METHODS

Sixty-five patients were enrolled; 34 patients with follicular lymphoma (FL), 15 patients with diffuse large B-cell lymphoma (DLBCL), and 16 patients with other lymphomas. The patients had received a median of two prior therapies (range, 1 to 4); 23% had received rituximab. Epratuzumab was given at 360 mg/m2 intravenously over 60 minutes followed by infusion of 375 mg/m2 rituximab, weekly for 4 consecutive weeks.

RESULTS

Combination therapy was well tolerated without greater toxicity than rituximab alone. The objective response (OR) rate was 47% (30 of 64) in assessable patients (46%; 30 of 65 in all patients), being highest in FL (64%; 21 of 33) and DLBCL (47%; seven of 15), and with 24% (eight of 33) and 33% (five of 15) achieving complete response (CR) or complete response unconfirmed (CRu) in these two groups, respectively. Two of six patients with marginal zone lymphoma responded to treatment (one CR). There was a trend for the response rates to be higher in patients with low prognostic index scores (statistically significant with respect to the Follicular Lymphoma International Prognostic Index score in FL patients), with 12 FL patients and three DLBCL patients in groups 0 to 1 having OR (CR/CRu) rates of 83% (33%) and 100% (100%), respectively. The median duration of response was 16 months for FL, with five patients currently progression free for 18 months to 30 months, and 6 months for DLBCL, with two patients currently progression free for 12 months and 18 months.

CONCLUSION

Epratuzumab combined with rituximab was well tolerated, demonstrating promising antilymphoma activity that warrants additional study.

Marked increased risk of Epstein-Barr virus-related complications with the addition of antithymocyte globulin to a nonmyeloablative conditioning prior to unrelated umbilical cord blood transplantation

Umbilical cord blood (UCB) is increasingly used as an alternative source of hematopoietic stem cells for transplantation for patients who lack a suitable sibling donor. Despite concerns about a possible increased risk of Epstein-Barr virus (EBV) posttransplantation lymphoproliferative disorder (PTLD) after UCB transplantation, early reports documented rates of PTLD comparable to those reported after HLA-matched unrelated marrow myeloablative (MA) transplantations. To further investigate the incidence of EBV PTLD after UCB transplantation and potential risk factors, we evaluated the incidence of EBV-related complications in 335 patients undergoing UCB transplantation with an MA or nonmyeloablative (NMA) preparative regimen. The incidence of EBV-related complications was a 4.5% overall, 3.3% for MA transplantations, and 7% for NMA transplantations. However, the incidence of EBV-related complications was significantly higher in a subset of patients treated with an NMA preparative regimen that included antithymocyte globulin (ATG) versus those that did not (21% vs 2%; P < .01). Nine of 11 patients who developed EBV PTLD were treated with rituximab (anti-CD20 antibody), with the 5 responders being alive and disease free at a median of 26 months. Use of ATG in recipients of an NMA preparative regimen warrants close monitoring for evidence of EBV reactivation and potentially preemptive therapy with rituximab.

Primary Mediastinal Large B‐Cell Lymphoma

Primary mediastinal large B-cell lymphoma represents a distinct entity with unique clinicopathologic features and a molecular gene-expression signature reminiscent of nodular sclerosis subtype of classical Hodgkin's lymphoma. Recent studies, including those using a refined molecular signature, suggest that the outcome is more favorable than that of diffuse large B-cell lymphoma. Using historical comparisons, dose-dense and dose-intensive regimens may be more effective than cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy; however, the impact of adding rituximab to these regimens and effect on outcome comparisons is unknown. Clinical trials exploring these questions in addition to the benefit of consolidative radiotherapy are necessary to definitively answer these questions.

Multicenter phase II study of the CyclOBEAP (CHOP-like + etoposide and bleomycin) regimen for patients with poor-prognosis aggressive lymphoma

Our aim was to study the efficacy of the addition of etoposide and bleomycin to a [cyclophosphamide (CPA), doxorubicin (DXR), vincristine (VCR), and prednisone (PDN)] CHOP-like regimen for the treatment of aggressive lymphoma. The CyclOBEAP regimen was administered over a total period of 12 weeks. Doxorubicin, 50 mg/m(2), was given every 2 weeks in combination with either cyclophosphamide, 1,000 mg/m(2), (weeks 1, 5, 9) or etoposide, 70 mg/m(2) qd x4 (weeks 3, 7, 11). During the alternate weeks, non-myelosuppressive vincristine, 1.4 mg/m(2) (maximum, 2.0 mg/body), was given either with bleomycin, 10 mg/m(2) (weeks 2, 6, 10), or alone (weeks 4,8,12). Prednisolone, 40 mg/m(2), was administered daily for 14 days during weeks 1-2, 5-6, and 9-10. There were 121 eligible patients and median age of 51 years. A complete response was achieved in 106 patients (88%) and a partial response in 11 patients. The 5-year overall survival (OS) rate was 72% and progression-free survival (PFS) rate was 62%. When the patients were divided according to the International Prognostic Index (IPI), the 5-year OS and PFS rates did not significantly differ among risk groups. When the patients with DLBCL were divided according to the IPI, the 5-year OS and PFS rates also did not significantly differ. World Health Organization (WHO) grade 4 neutropenia was observed in 91 patients and thrombocytopenia in 13 patients. No treatment-related deaths were observed. The addition of etoposide and bleomycin to CHOP therapy may enhance the effect of CHOP therapy for aggressive lymphoma. We will perform a prospective study of CyclOBEAP regimen combined with rituximab and test its safety and efficacy.

Antitumor efficacy of a combination of CMC-544 (inotuzumab ozogamicin), a CD22-targeted cytotoxic immunoconjugate of calicheamicin, and rituximab against non-Hodgkin's B-cell lymphoma

PURPOSE

CMC-544 is a CD22-targeted cytotoxic immunoconjugate, currently being evaluated in B-cell non-Hodgkin's lymphoma (B-NHL) patients. Rituximab is a CD20-targeted antibody commonly used in B-NHL therapy. Here, we describe antitumor efficacy of a combination of CMC-544 and rituximab against B-cell lymphoma (BCL) in preclinical models.

EXPERIMENTAL DESIGN

BCLs were cultured in vitro with CMC-544, rituximab, or their combination. BCLs were injected either s.c. or i.v. to establish localized s.c. BCL in nude mice or disseminated BCL in severe combined immunodeficient mice, respectively. I.p. treatment with CMC-544 or rituximab was initiated at various times either alone or in combination and its effect on s.c. BCL growth or survival of mice with disseminated BCL was monitored.

RESULTS

In vitro growth-inhibitory activity of CMC-544 combined with rituximab was additive. Rituximab but not CMC-544 exhibited effector functions, such as antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Rituximab was less effective in inhibiting growth of established BCL xenografts than developing xenografts. In contrast, CMC-544 was equally effective against both developing and established BCL xenografts. Although CMC-544 and rituximab individually caused partial inhibition of the growth of BCL xenografts at suboptimal doses examined, their combination suppressed xenograft growth by >90%. In a disseminated BCL model, 60% of CMC-544-treated mice and 20% of rituximab-treated mice survived for 125 days. In contrast, 90% of mice treated with the combination of CMC-544 and rituximab survived for longer than 125 days.

CONCLUSION

The demonstration of superior antitumor activity of a combination of CMC-544 and rituximab described here provides the preclinical basis for its clinical evaluation as a treatment option for B-NHL.

State-of-the-art therapeutics: diffuse large B-cell lymphoma

This article is a review of the improvement in the treatment of patients with diffuse large B-cell lymphoma made during the last 10 years. Patients with diffuse large B-cell lymphoma now have a better outcome with longer survival because of two major developments: (1) increasing the dose of active drugs with shortening the time between cycles, resulting in dose-dense and/or dose-intense regimens; and (2) combining rituximab with chemotherapy. Both strategies were associated with higher response rates, lower relapse rates, longer event-free survival, longer time to progression, and longer overall survival, particularly in patients without adverse prognostic parameters. A combination of dose-dense, dose-intense regimens plus rituximab is currently being tested for poor-risk patients with diffuse large B-cell lymphoma. However, much work has to be done for patients with high-risk lymphoma. It may come with a better definition of genetic abnormalities specifically associated with refractoriness to chemotherapy.

Introduction of combined CHOP plus rituximab therapy dramatically improved outcome of diffuse large B-cell lymphoma in British Columbia

PURPOSE

For more than two decades, cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been the standard therapy for diffuse large B-cell lymphoma (DLBCL). The addition of rituximab to CHOP has been shown to improve outcome in elderly patients with DLBCL. We conducted a population-based analysis to assess the impact of this combination therapy on adult patients with DLBCL in the province of British Columbia (BC).

METHODS

We compared outcomes during a 3-year period; 18 months before (prerituximab) and 18 months after (postrituximab) institution of a policy recommending the combination of CHOP and rituximab for all patients with newly diagnosed advanced-stage (stage III or IV or stage I or II with "B" symptoms or bulky [> 10 cm] disease) DLBCL.

RESULTS

A total of 292 patients were evaluated; 140 in the prerituximab group (median follow-up, 42 months) and 152 in the postrituximab group (median follow-up, 24 months). Both progression-free survival (risk ratio, 0.56; 95% CI, 0.39 to 0.81; P = .002) and overall survival (risk ratio, 0.40; 95% CI, 0.27 to 0.61, P < .0001) were significantly improved in the postrituximab group. After controlling for age and International Prognostic Index score, era of treatment remained a strong independent predictor of progression-free survival (risk ratio, 0.59; 95% CI, 0.41 to 0.85; P = .005) and overall survival (risk ratio, 0.43; 95% CI, 0.29 to 0.66; P < .001). The benefit of treatment in the postrituximab era was present regardless of age.

CONCLUSION

The addition of rituximab to CHOP chemotherapy has resulted in a dramatic improvement in outcome for DLBCL patients of all ages in the province of BC.

Long-term results of the R-CHOP study in the treatment of elderly patients with diffuse large B-cell lymphoma: a study by the Groupe d'Etude des Lymphomes de l'Adulte

PURPOSE

To analyze the long-term outcome of patients included in the Lymphome Non Hodgkinien study 98-5 (LNH98-5) comparing cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) to rituximab plus CHOP (R-CHOP) in elderly patients with diffuse large B-cell lymphoma.

PATIENTS AND METHODS

LNH98-5 was a randomized study that included 399 previously untreated patients, age 60 to 80 years, with diffuse large B-cell lymphoma. Patients received eight cycles of classical CHOP (cyclophosphamide 750 mg/m(2), doxorubicin 50 mg/m(2), vincristine 1.4 mg/m(2), and prednisone 40 mg/m(2) for 5 days) every 3 weeks. In R-CHOP, rituximab 375 mg/m(2) was administered the same day as CHOP. Survivals were analyzed using the intent-to-treat principle.

RESULTS

Median follow-up is 5 years at present. Event-free survival, progression-free survival, disease-free survival, and overall survival remain statistically significant in favor of the combination of R-CHOP (P = .00002, P < .00001, P < .00031, and P < .0073, respectively, in the log-rank test). Patients with low-risk or high-risk lymphoma according to the age-adjusted International Prognostic Index have longer survivals if treated with the combination. No long-term toxicity appeared to be associated with the R-CHOP combination.

CONCLUSION

Using the combination of R-CHOP leads to significant improvement of the outcome of elderly patients with diffuse large B-cell lymphoma, with significant survival benefit maintained during a 5-year follow-up. This combination should become the standard for treating these patients.

Early results of a chemoimmunotherapy regimen of fludarabine, cyclophosphamide, and rituximab as initial therapy for chronic lymphocytic leukemia

PURPOSE

Fludarabine and cyclophosphamide (FC), which are active in treatment of chronic lymphocytic leukemia (CLL), are synergistic with the monoclonal antibody rituximab in vitro in lymphoma cell lines. A chemoimmunotherapy program consisting of fludarabine, cyclophosphamide, and rituximab (FCR) was developed with the goal of increasing the complete remission (CR) rate in previously untreated CLL patients to >/= 50%.

PATIENTS AND METHODS

We conducted a single-arm study of FCR as initial therapy in 224 patients with progressive or advanced CLL. Flow cytometry was used to measure residual disease. Results and safety were compared with a previous regimen using FC.

RESULTS

The median age was 58 years; 75 patients (33%) had Rai stage III to IV disease. The CR rate was 70% (95% CI, 63% to 76%), the nodular partial remission rate was 10%, and the partial remission rate was 15%, for an overall response rate of 95% (95% CI, 92% to 98%). Two thirds of patients evaluated with flow cytometry had less than 1% CD5- and CD19-coexpressing cells in bone marrow after therapy. Grade 3 to 4 neutropenia occurred during 52% of courses; major and minor infections were seen in 2.6% and 10% of courses, respectively. One third of the 224 patients had >/= one episode of infection, and 10% had a fever of unknown origin.

CONCLUSION

FCR produced a high CR rate in previously untreated CLL. Most patients had no detectable disease on flow cytometry at the end of therapy. Time to treatment failure analysis showed that 69% of patients were projected to be failure free at 4 years (95% CI, 57% to 81%).

Diffuse aggressive lymphoma

The aggressive non-Hodgkin's lymphomas can be cured in more than half of the cases. However, there has been great variation in the results reported from individual clinical Phase II trials. This variation in result can be attributed to unrecognized heterogeneity in this group of diseases. Recent clinical and molecular studies have enabled us to define more homogenous population in which new therapies can be studied. For patients with advanced stages of diffuse large B cell lymphoma, a new standard of therapy exists. For patients with localized aggressive non-Hodgkin's lymphomas, heterogeneity in patient selection prevents us from defining a new standard of care. Finally, in mantle cell lymphoma, new opportunities in drug discovery may permit advances in the treatment of this uniformly fatal malignancy. In Section I, Dr. Richard Fisher reviews the development of combination chemotherapy for patients with advanced stage diffuse large B cell lymphoma. Because of great heterogeneity in patients enrolled in Phase II studies, large randomized Phase III studies were required in the 1980s to define CHOP has the standard of care. This heterogeneity has now been defined carefully in the international prognostic factor index and more recently by gene array studies. It will now need to be incorporated prospectively into studies or retrospectively analyzed to understand clinical trial results. The addition of rituximab to CHOP has now been demonstrated to improve survival in two large Phase III studies in elderly patients. A recently presented study in younger patients suggests a similar benefit. Thus CHOP/rituximab has become the established standard of care for all patients with advanced stage diffuse large B cell lymphoma. Other concepts being evaluated to further improve on these results include: dose intensification; initial treatment with chemotherapy plus allogeneic stem cell transplantation; and infusional chemotherapy. Finally, the status of the treatment for relapsed patients will be defined. In Section II, Dr. Thomas Miller defines the treatment for limited stage aggressive non-Hodgkin's lymphoma. Randomized trials have demonstrated the critical importance of initial chemotherapy for treatment of these patients. The amount of chemotherapy given needs to be increased for patients with bulky tumors. In most circumstances radiotherapy after the completion of chemotherapy has been shown to be advantageous. A modification of the international prognostic factor index for patients with early stage disease is presented to permit comparisons among different populations. Recently reported early-stage studies need to be analyzed in terms of the heterogeneity of the patients involved to understand the reported results. The addition of monoclonal antibodies, as well as radioimmunotherapy, are being tested in an effort to improve on the results for the poor prognosis patients. In Section III, Dr. Owen O'Connor describes the pathology immunophenotype and natural history of mantle cell lymphoma. Conventional treatment strategies with combination chemotherapy achieved objective responses in approximately half of the patients but no significant impact on survival. The addition to rituximab to CHOP chemotherapy or other treatment strategies appears to improve the remission rate; however, no major changes in survival have also been reported. Excellent single institution results have been reported with HyperCVAD plus rituximab regimen, which is currently being tested in a national cooperative group trial. The most excitement in this field currently relates to the variety of new agents which appear to have significant activity in relapsed patients with mantle cell lymphoma. This includes the proteosome inhibitor, bortezomib, which is shown to have approximately a 50% response rate with some CRs and reasonable durability in early single institution Phase II studies. Larger national multi-center trials are ongoing. In addition, agents such as thalidomide, flavopiridol, and piroxantrone will be reviewed.