Brian K. Link

Rituximab chimeric anti-CD20 monoclonal antibody therapy for relapsed indolent lymphoma: half of patients respond to a four-dose treatment program.

PURPOSE The CD20 antigen is expressed on more than 90% of B-cell lymphomas. It is appealing for targeted therapy, because it does not shed or modulate. A chimeric monoclonal antibody more effectively mediates host effector functions and is itself less immunogenic than are murine antibodies. PATIENTS AND METHODS This was a multiinstitutional trial of the chimeric anti-CD20 antibody, IDEC-C2B8. Patients with relapsed low grade or follicular lymphoma received an outpatient treatment course of IDEC-C2B8 375 mg/m2 intravenously weekly for four doses. RESULTS From 31 centers, 166 patients were entered. Of this intent-to-treat group, 48% responded. With a median follow-up duration of 11.8 months, the projected median time to progression for responders is 13.0 months. Serum antibody levels were sustained longer after the fourth infusion than after the first, and were higher in responders and in patients with lower tumor burden. The majority of adverse events occurred during the first infusion and were grade 1 or 2; fever and chills were the most common events. Only 12% of patients had grade 3 and 3% grade 4 toxicities. A human antichimeric antibody was detected in only one patient. CONCLUSION The response rate of 48% with IDEC-C2B8 is comparable to results with single-agent cytotoxic chemotherapy. Toxicity was mild. Attention needs to be paid to the rate of antibody infusion, with titration according to toxicity. Further investigation of this agent is warranted, including its use in conjunction with standard chemotherapy.

Discovery and prioritization of somatic mutations in diffuse large B-cell lymphoma (DLBCL) by whole-exome sequencing

To gain insight into the genomic basis of diffuse large B-cell lymphoma (DLBCL), we performed massively parallel whole-exome sequencing of 55 primary tumor samples from patients with DLBCL and matched normal tissue. We identified recurrent mutations in genes that are well known to be functionally relevant in DLBCL, including MYD88, CARD11, EZH2, and CREBBP. We also identified somatic mutations in genes for which a functional role in DLBCL has not been previously suspected. These genes include MEF2B, MLL2, BTG1, GNA13, ACTB, P2RY8, PCLO, and TNFRSF14. Further, we show that BCL2 mutations commonly occur in patients with BCL2/IgH rearrangements as a result of somatic hypermutation normally occurring at the IgH locus. The BCL2 point mutations are primarily synonymous, and likely caused by activation-induced cytidine deaminase–mediated somatic hypermutation, as shown by comprehensive analysis of enrichment of mutations in WRCY target motifs. Those nonsynonymous mutations that are observed tend to be found outside of the functionally important BH domains of the protein, suggesting that strong negative selection against BCL2 loss-of-function mutations is at play. Last, by using an algorithm designed to identify likely functionally relevant but infrequent mutations, we identify KRAS, BRAF, and NOTCH1 as likely drivers of DLBCL pathogenesis in some patients. Our data provide an unbiased view of the landscape of mutations in DLBCL, and this in turn may point toward new therapeutic strategies for the disease.

Response Assessment of Aggressive Non-Hodgkin’s Lymphoma by Integrated International Workshop Criteria and Fluorine-18–Fluorodeoxyglucose Positron Emission Tomography

PURPOSE To determine whether a response classification based on integration of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) into the International Workshop Criteria (IWC) provides a more accurate response assessment than IWC alone in patients with non-Hodgkins lymphoma (NHL). PATIENTS AND METHODS Fifty-four patients with aggressive NHL who underwent FDG-PET and computed tomography 1 to 16 weeks after four to eight cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone were assessed for complete response (CR), unconfirmed CR (CRu), partial response (PR), stable disease (SD), and progressive disease (PD) by the IWC and by integrated IWC and FDG-PET (IWC+PET). Progression-free survival (PFS) was also compared between IWC- and IWC+PET-assigned response designations. RESULTS By IWC, 17 patients had a CR, seven had a CRu, 19 had a PR, nine had SD, and two had PD. In comparison, by IWC+PET, 35 patients had a CR, 12 had a PR, six had SD, one had PD, and zero had a CRu. In separate multivariate models, PFS was significantly shorter in patients with PR than in those with a CR using IWC (hazard ratio [HR], 8.9; P = .021) or IWC+PET (HR, 29.7; P = .0003). However, when the two classifications were included in the same multivariate model, only IWC+PET was a statistically significant independent predictor for PFS (P = .008 v P = .72 for IWC). In addition, when patients with a PR by IWC and a CR by IWC+PET were compared with those with a CR by IWC and a CR by IWC+PET, there was no significant difference in PFS (HR, 1.6; P = .72), indicating that IWC+PET identified a subset of IWC-PR patients with a more favorable prognosis. CONCLUSION Compared with IWC, the IWC+PET-based assessment provides a more accurate response classification in patients with aggressive NHL.

Single-Agent Monoclonal Antibody Efficacy in Bulky Non-Hodgkin's Lymphoma: Results of a Phase II Trial of Rituximab

PURPOSE A phase II trial was performed to evaluate the safety and efficacy of rituximab, a chimeric anti-CD20 monoclonal antibody, in patients with bulky (> 10-cm lesion) relapsed or refractory low-grade or follicular non-Hodgkins lymphoma (NHL). PATIENTS AND METHODS Thirty-one patients received intravenous infusions of rituximab 375 mg/m(2) weekly for four doses. All patients had at least one prior therapy (median, three; range, one to 13) and had progressive disease at study entry. Patients were a median of 4 years from diagnosis. RESULTS No patient had treatment discontinued because of an adverse event. No patient developed human antichimeric antibody. The overall response rate in 28 assessable patients was 43% with a median time to progression of 8.1 months (range, 4.5 to 18.6+ months) and median duration of response of 5.9 months (range, 2.8 to 12.1+ months). The average decrease in lesion size in patients who achieved a partial response was 76%, and patients with stable disease had a decrease in average lesion size of 26%. Median serum antibody concentration was higher in responders compared with nonresponders, and a negative correlation was shown between antibody concentration and tumor bulk at baseline. CONCLUSION Rituximab single-agent outpatient therapy is safe and shows significant clinical activity in patients with bulky relapsed or refractory low-grade or follicular B-cell NHL.

Improved Survival of Follicular Lymphoma Patients in the United States

PURPOSE Despite several new treatment options, single- and multi-institution analyses have not clarified whether survival patterns in follicular lymphoma (FL) patients have changed in recent decades. We undertook a study using a large population-based registry to analyze survival patterns among patients with FL. PATIENTS AND METHODS Surveillance, Epidemiology, and End Results morphology codes were used to identify 14,564 patients diagnosed with FL between 1978 and 1999. Observed median survival times, Kaplan-Meier survival curves, proportional death hazard ratios, and relative survival rates were calculated. Joinpoint regression analysis was used to identify trends in annual adjusted death hazard ratios. RESULTS An improvement in survival of all patients with FL was observed between each of three diagnosis eras (1978 to 1985, 1986 to 1992, and 1993 to 1999) by log-rank tests. Among patients with stage-specific data, the median survival time improved from 84 months (95% CI, 81 to 88 months) in the 1983 to 1989 era to 93 months (95% CI, 89 to 97 months) in the 1993 to 1999 era. Similar findings were identified across sex and age groups and for subsets including advanced-stage, large-cell FL and the combined subset of small cleaved- and mixed-cell FL. The inter-era survival advantage observed in white patients was not observed for black patients. The relative risk of death decreased by 1.8% per year over the 1983 to 1999 observation period. CONCLUSION The survival of patients with FL in the United States has improved over the last 25 years. The survival improvement may be a result of the sequential application of effective therapies and improved supportive care.

First clinical use of ofatumumab, a novel fully human anti-CD20 monoclonal antibody in relapsed or refractory follicular lymphoma : results of a phase 1/2 trial

Ofatumumab is a unique monoclonal antibody that targets a distinct small loop epitope on the CD20 molecule. Preclinical data show that ofatumumab is active against B-cell lymphoma/chronic lymphocytic leukemia cells with low CD20-antigen density and high expression of complement inhibitory molecules. In a phase 1/2 trial evaluating safety and efficacy of ofatumumab in relapsed or refractory follicular non-Hodgkin lymphoma (FL) grade 1 or 2, 4 dose groups of 10 patients received 4 weekly infusions of 300, 500, 700, or 1000 mg. Patients had a median of 2 prior FL therapies and 13% had elevated lactate dehydrogenase. No safety concerns or maximum tolerated dose was identified. A total of 274 adverse events were reported; 190 were judged related to ofatumumab, most occurring on the first infusion day with Common Terminology Criteria grade 1 or 2. Eight related events were grade 3. Treatment caused immediate and profound B-cell depletion, and 65% of patients reverted to negative BCL2 status. Clinical response rates ranged from 20% to 63%. Median time to progression for all patients/responders was 8.8/32.6 months, and median duration of response was 29.9 months at a median/maximum follow-up of 9.2/38.6 months. Ofatumumab is currently being evaluated in patients with rituximab-refractory FL. This trial was registered at www.clinicaltrials.gov as #NCT00092274.

Follicular Lymphoma in the United States: First Report of the National LymphoCare Study

PURPOSE Optimal therapy of follicular lymphoma (FL) is not defined. We analyzed a large prospective cohort study to identify current demographics and patterns of care of FL in the United States. PATIENTS AND METHODS The National LymphoCare Study is a multicenter, longitudinal, observational study designed to collect information on treatment regimens and outcomes for patients with newly diagnosed FL in the United States. Patients were enrolled between 2004 and 2007. There is no study-specific prescribed treatment regimen or intervention. RESULTS Two thousand seven hundred twenty-eight subjects were enrolled at 265 sites, including the 80% of patients enrolled from nonacademic sites. Using the Follicular Lymphoma International Prognostic Index (FLIPI), three distinct groups independent of histologic grade could be defined. Initial therapeutic strategy was: observation, 17.7%; rituximab monotherapy, 13.9%; clinical trial 6.1%; radiation therapy, 5.6%; chemotherapy only, 3.2%; chemotherapy plus rituximab, 51.9%. Chemotherapy plus rituximab regimens were: rituximab plus cyclophosphamide, doxorubicin, vincristine, prednisone, 55.0%; rituximab plus cyclophosphamide, vincristine, and prednisone, 23.1%; rituximab plus fludarabine based, 15.5%; other, 6.4%. The choice to initiate therapy rather than observe was associated with age, FLIPI, stage, and grade (P < .01). Significant differences in treatment (P < .01) across regions of the United States were noted. Contrary to practice guidelines, treatment of stage I FL frequently omits radiation therapy. CONCLUSION Widely disparate therapeutic approaches are utilized for FL. Initial therapy is deferred in a small subset of patients. There is no single standard of care for the treatment of de novo FL, although antibody use is ubiquitous when therapy is initiated. These disparate approaches to the initial care of patients with FL render a heterogeneous group of patients at relapse.

Vitamin D Insufficiency and Prognosis in Non-Hodgkin's Lymphoma

PURPOSE Vitamin D insufficiency is common in the United States, with low levels linked in some studies to higher cancer incidence, including non-Hodgkins lymphoma (NHL). Recent data also suggest that vitamin D insufficiency is related to inferior prognosis in some cancers, although there are no data for NHL. PATIENTS AND METHODS We tested the hypothesis that circulating 25-hydroxyvitamin D [25(OH)D] levels are predictive of event-free survival (EFS) and overall survival (OS) in a prospective cohort of 983 newly diagnosed patients with NHL. 25(OH)D and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] levels were measured by liquid chromatography-tandem mass spectrometry. RESULTS Mean age at diagnosis was 62 years (range, 19 to 94 years); 44% of patients had insufficient 25(OH)D levels (< 25 ng/mL) within 120 days of diagnosis. Median follow-up was 34.8 months; 404 events and 193 deaths (168 from lymphoma) occurred. After adjusting for known prognostic factors and treatment, 25(OH)D insufficient patients with diffuse large B-cell lymphoma (DLBCL) had inferior EFS (hazard ratio [HR], 1.41; 95% CI, 0.98 to 2.04) and OS (HR, 1.99; 95% CI, 1.27 to 3.13); 25(OH)D insufficient patients with T-cell lymphoma also had inferior EFS (HR, 1.94; 95% CI, 1.04 to 3.61) and OS (HR, 2.38; 95% CI, 1.04 to 5.41). There were no associations with EFS for the other NHL subtypes. Among patients with DLBCL and T-cell lymphoma, higher 1,25(OH)(2)D levels were associated with better EFS and OS, suggesting that any putative tumor 1-α-hydroxylase activity did not explain the 25(OH)D associations. CONCLUSION 25(OH)D insufficiency was associated with inferior EFS and OS in DLBCL and T-cell lymphoma. Whether normalizing vitamin D levels in these patients improves outcomes will require testing in future trials.

CD20-Directed Antibody-Mediated Immunotherapy Induces Responses and Facilitates Hematologic Recovery in Patients With Waldenstrom's Macroglobulinemia.

Waldenstroms macroglobulinemia (WM, lymphoplasmacytic lymphoma) is a B-cell lymphoproliferative disorder in which CD20 is expressed on tumor cells from most patients. Several small studies have suggested a benefit from the anti-CD20 monoclonal antibody rituximab (Rituxan, MabThera) in patients with WM. In this retrospective study, we examined the outcome of 30 previously unreported patients with WM who received treatment with single-agent rituximab (median age 60; range 32–83 years old). The median number of prior treatments for these patients was 1 (range 0–6), and 14 patients (47%) received a nucleoside analogue before rituximab therapy. Patients received a median of 4.0 (1–11.3) infusions of rituximab (375 mg/m2). Three patients received steroids with their infusions for prophylaxis of rituximab-related infusion syndrome. Overall, treatment was well tolerated. Median immunoglobulin M (IgM) levels for all patients declined from 2,403 mg/dL (range 720–7639 mg/dL) to 1,525 mg/dL (range 177–5,063 mg/dL) after rituximab therapy (p = 0.001), with 8 of 30 (27%) and 18 of 30 (60%) patients demonstrating >50% and >25% decline in IgM, respectively. Median bone marrow lymphoplasmacytic (BM LPC) cell involvement declined from 60% (range 5–90%) to 15% (range 0–80%) for 17 patients for whom pre-and post-BM biopsies were performed (p < 0.001). Moreover, 19 of 30 (63%) and 15 of 30 (50%) patients had an increase in their hematocrit (HCT) and platelet (PLT) counts, respectively. Before rituximab therapy, 7 of 30 (23.3%) patients were either transfusion or erythropoietin dependent, whereas only 1/30 (3.3%) patients required transfusions (no erythropoietin) after rituximab. Overall responses after treatment with rituximab were as follows: 8 (27%) and 10 (33%) of the patients achieved a partial (PR) and a minor (MR) response, respectively, and an additional 9 (30%) of patients demonstrated stable disease (SD). No patients attained a complete response. The median time to treatment failure for responding (PR and MR) patients was 8.0 months (mean 8.4; range 3–20+ months), and 5.0 months (mean 6.1; range 3–12+ months) for patients with SD. These studies therefore demonstrate that rituximab is an active agent in WM. Marked increases in HCT and PLT counts were noted for most patients, including patients with WM who had MR or SD. A prospective clinical trial to more completely define the benefit of single-agent rituximab in patients with WM has been initiated by many of our centers.

Early Relapse of Follicular Lymphoma After Rituximab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone Defines Patients at High Risk for Death: An Analysis From the National LymphoCare Study

PURPOSE Twenty percent of patients with follicular lymphoma (FL) experience progression of disease (POD) within 2 years of initial chemoimmunotherapy. We analyzed data from the National LymphoCare Study to identify whether prognostic FL factors are associated with early POD and whether patients with early POD are at high risk for death. PATIENTS AND METHODS In total, 588 patients with stage 2 to 4 FL received first-line rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Two groups were defined: patients with early POD 2 years or less after diagnosis and those without POD within 2 years, the reference group. An independent validation set, 147 patients with FL who received first-line R-CHOP, was analyzed for reproducibility. RESULTS Of 588 patients, 19% (n = 110) had early POD, 71% (n = 420) were in the reference group, 8% (n = 46) were lost to follow-up, and 2% (n = 12) died without POD less than 2 years after diagnosis. Five-year overall survival was lower in the early-POD group than in the reference group (50% v 90%). This trend was maintained after we adjusted for FL International Prognostic Index (hazard ratio, 6.44; 95% CI, 4.33 to 9.58). Results were similar for the validation set (FL International Prognostic Index-adjusted hazard ratio, 19.8). CONCLUSION In patients with FL who received first-line R-CHOP, POD within 2 years after diagnosis was associated with poor outcomes and should be further validated as a standard end point of chemoimmunotherapy trials of untreated FL. This high-risk FL population warrants further study in directed prospective clinical trials.