A Canadian perspective on the use of immunoglobulin therapy to reduce infectious complications in chronic lymphocytic leukemia

Infections are a major cause of morbidity and mortality in patients with chronic lymphocytic leukemia (cll), who typically have increased susceptibility because of hypogammaglobulinemia (hgg) related to their disease and its treatment. Immunoglobulin replacement therapy (igrt) has been shown to reduce the frequency of bacterial infections and associated hospitalizations in patients with hgg or a history of infection, or both. However, use of igrt in cll is contentious. Studies examining such treatment were conducted largely before the use of newer chemoimmunotherapies, which can extend lifespan, but do not correct the hgg inherent to the disease. Thus, the utility of igrt has to be re-evaluated in the current setting. Here, we discuss the evidence for the use of igrt in cll and provide a practical approach to its use in the prevention and management of infections.

An open-label expanded-access trial of bendamustine in patients with rituximab-refractory indolent non-Hodgkin lymphoma or previously untreated chronic lymphocytic leukemia: BEND-ACT

BACKGROUND

Bendamustine is a bifunctional alkylating agent with unique properties that distinguish it from other agents in its class. Bendamustine is used as monotherapy or in combination with other agents to treat patients with non-Hodgkin lymphoma (nhl) and chronic lymphocytic leukemia (cll).

METHODS

The prospective interventional open-label bend-act trial evaluated bendamustine in patients with rituximab-refractory indolent nhl (inhl) and previously untreated cll. Study objectives were to assess the safety and tolerability of bendamustine monotherapy and to provide patients with access to bendamustine before Health Canada approval. The study aimed to enrol up to 100 patients. All patients with inhl received an intravenous dose of bendamustine 120 mg/m(2) over 60 minutes on days 1 and 2 for up to eight 21- or 28-day treatment cycles. All patients with cll received an intravenous dose of bendamustine 100 mg/m(2) over 30 minutes on days 1 and 2 for up to six 28-day treatment cycles.

RESULTS

Of 90 patients treated on study (16 with cll and 74 with inhl), 35 completed the study (4 with cll and 31 with inhl). The most common treatment-emergent adverse events (teaes) were nausea (70%), fatigue (57%), vomiting (40%), and diarrhea (33%)-mostly grades 1 and 2. Ondansetron was the most common supportive medication used in the patients (63.5% of those with inhl and 68.8% of those with cll). Neutropenia (32%), anemia (23%), and thrombocytopenia (21%) were the most frequent hematologic teaes, with neutropenia being the most common grade 3 or 4 teae leading to dose modification. Dose delays occurred in 28 patients (31.3%) because of grade 3 or 4 teaes, with a higher incidence of dose delays being observed in inhl patients on the 21-day treatment cycle than in those on the 28-day treatment cycle (50.0% vs. 24.1%). During the study, 33 patients (36.7%) experienced at least 1 serious adverse event, and 4 deaths were reported (all in patients with inhl).

CONCLUSIONS

The type and frequency of the teaes reported accorded with observations in earlier clinical trials and post-marketing experiences, thus confirming the acceptable and manageable safety profile of bendamustine.

Alemtuzumab in clinical practice: A British Columbia experience

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Background: Limited information is available on alemtuzumab in the non-clinical trial setting. We evaluated its efficacy and safety in 42 consecutive unselected patients who received alemtuzumab monotherapy in British Columbia between October 2002 and August 2006. Methods: Information on patient demographics, baseline clinical and pathologic characteristics, dose and schedule of treatment, clinical response, survival, and toxicities associated with alemtuzumab were collected retrospectively. Results: Thirty-nine of 42 patients had chronic lymphocytic leukemia, 2 had mycosis fungoides, and 1 had T-cell post-transplant lymphoproliferative disorder. In contrast to previous reports, 42% were treated by community practitioners and 83% received alemtuzumab subcutaneously. The median time from diagnosis to alemtuzumab was 58 months, with a median age of 63 years at alemtuzumab treatment. Patients received a median of 4 treatments prior to starting alemtuzumab. One of 42 patients (2%) achieved a complete response, 20 (48%) achieved a partial response, 13 (31%) had stable disease, and 4 (10%) had progressive disease. The median post-alemtuzumab overall survival was 15.1 months and the median progression-free survival was 5.4 months. Response to alemtuzumab correlated with an increased progression- free survival (11 months versus 3.6 months, p=0.001) and time to next treatment (15.7 months versus 5.4 months, p=0.004). Significant adverse events included grade 3 or 4 neutropenia (75%) or thrombocytopenia (42%), infections (54%) including CMV reactivation (6%), and death (12%). Patients who received alemtuzumab in the community setting had a higher incidence of febrile neutropenia (p=0.05) and infection (p=0.03) compared to academic centres, although no difference in overall survival was noted. Conclusion: Alemtuzumab can be safely administered in a wide variety of clinical settings, including community practice, and is associated with a high level of activity.

No significant financial relationships to disclose.

Cost-effectiveness (CE) analysis of CHOP and rituximab for diffuse large B-cell lymphoma (DLBCL) in British Columbia (BC)

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Background: The BC Cancer Agency (BCCA) provides province-wide, population-based care. Outcomes are monitored to verify therapeutic effectiveness and justify funding for systemic treatment policies. The CE of rituximab with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) (CHOP-R) for DLBCL was compared to its predecessor, CHOP alone. Methods: This was a pragmatic population-based CE analysis based on the original cohort of advanced DLBCL patients described by Sehn et al (JCO 2005) who received either CHOP or CHOP-R between Sept 1999 and Aug 2002 (18-months pre and post availability of rituximab in BC) according to standard BCCA treatment policy at the time. The primary endpoint was CE in terms of life-expectancy (LE) at a median follow-up of 4 years (cost-per-life-year-gained). Costs were incorporated into a decision analysis including primary systemic therapy and downstream chemotherapy, radiotherapy, and stem-cell transplant (SCT). Actual incidence of each downstream therapy was converted to a probability for each group. Downstream therapy costs were then multiplied by these probabilities and added to the respective primary treatment costs. The CE analysis took the BCCA perspective which includes all direct costs for active cancer treatment, and hospitalization for SCT, but not ambulatory supportive care. Sensitivity analyses varying LE to the extremes of its 95% CI, modeling out to 15 years and discounting at 0, 3, and 5% were performed. Results: 292 patients were included and categorized to treatment received: 148 CHOP and 144 CHOP-R (median follow- up 5.4 and 4 years respectively). LE to 4 years was 30.18 months for CHOP and 39.44 for CHOP-R. OS at 4 years was 48.8% and 70.1% for CHOP and CHOP-R respectively (p<0.0001) Respective costs of primary and downstream therapy were $4,682 and $7,198 for CHOP versus $26,366 and $6,228 for CHOP-R. The incremental CE ratio at 4 years median follow-up was $26,844 CDN per life year gained. Results were robust across univariate sensitivity analyses conducted. Conclusions: At 4 years median follow-up, CHOP-R improves LE and appears to be economically attractive at conventional thresholds. CE is an increasingly useful tool for the BCCA in making decisions about new cancer therapies.

No significant financial relationships to disclose.

A phase II study of bortezomib in mantle cell lymphoma: the National Cancer Institute of Canada Clinical Trials Group trial IND.150

BACKGROUND

We evaluated the activity and toxic effects of bortezomib in patients with mantle cell lymphoma.

PATIENTS AND METHODS

Thirty patients, including 29 eligible patients, were enrolled; 13 had received no prior chemotherapy. The dose of bortezomib was 1.3 mg/m2 given on days 1, 4, 8 and 11 every 21 days. Response was assessed according to the International Workshop Criteria for non-Hodgkin's lymphoma and toxicity graded using the National Cancer Institute Common Toxicity Criteria version 2.0.

RESULTS

There were 13 responding patients (46.4%; 95% confidence interval=27.5% to 66.1%), including one unconfirmed complete remission. The median response duration was 10 months. Response rates were similar in previously untreated (46.2%) and treated (46.7%) patients. Neurological toxicity and myalgia led to treatment discontinuation in 10 patients after two to seven treatment cycles. Five serious adverse events (including two deaths) associated with fluid retention were observed in the first 12 patients. We subsequently excluded patients with baseline effusions, dyspnea or edema; no further events were seen.

CONCLUSIONS

Bortezomib is active in treating patients with mantle cell lymphoma. While cumulative neuromuscular toxic effects limited therapy duration and specific issues related to fluid retention require further evaluation, continued study of this drug in combination regimens is warranted.

Theoretical computation of phase locking in embryonic atrial heart cell aggregates

The effects of periodic stimulation of spontaneously beating aggregates of chick atrial heart cells are considered. Provided the effects of a single stimulus do not change the properties of the oscillation, and that the oscillation is re-established rapidly following a stimulus, this system can be modeled by one-dimensional finite difference equations. These equations employ experimentally generated phase resetting data that describe the effects of a single isolated stimulus at different phases of the oscillation. A complete analysis of the predicted dynamics is given over a broad range of stimulation frequencies and amplitudes. Prominent features of the dynamics include phase locking, bistability, chaos, and disappearance of Arnold tongues at large stimulation amplitudes. The fine details of the bifurcations are sensitive to properties of the phase resetting curves, and consequently, the observed bifurcations are not expected to be "universal" for larger stimulation amplitudes. Experimental traces show many correspondences with theoretical computations.