Updates from the 2017 American Society of Hematology Annual Meeting: Practice-Changing Studies in Untreated Chronic Lymphocytic Leukemia

The 2017 annual meeting of the American Society of Hematology took place 9–12 December in Atlanta, Georgia. At the meeting, the oral presentations included results from key studies on the first-line treatment of chronic lymphocytic leukemia. A series of phase ii studies focusing on the efficacy and safety of novel treatment strategies were especially notable. One concerned the health-related quality of life results from the gibb study, which had examined the combination of obinutuzumab and bendamustine. A second evaluated the venetoclax–ibrutinib regimen in patients with high-risk disease. The third assessed the combination of ibrutinib, fludarabine, cyclophosphamide, and obinutuzumab in patients with mutated immunoglobulin heavy-chain variable region genes. The fourth examined the combination of ibrutinib, fludarabine, cyclophosphamide, and rituximab in younger patients. And the final study evaluated obinutuzumab–ibrutinib followed by a minimal residual disease strategy in fit patients. Our meeting report describes the foregoing studies and presents interviews with investigators and commentaries by Canadian hematologists about the potential effects on Canadian practice.

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.

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.

Stem cell transplantation for myelofibrosis: a report from two Canadian centers

We describe the course of 25 patients with myelofibrosis (MF) due to agnogenic myeloid metaplasia (n=19) or essential thrombocytosis (n=6) who underwent allogeneic stem cell transplantation (SCT) at one of two Canadian centers. The median age at transplantation was 48.7 (IQR 45.9-50.4) years and transplantation was carried out at a median of 10.7 (IQR 5.67-26.5) months after diagnosis. Granulocyte engraftment (absolute neutrophil count >0.5 x 109/l) occurred at a median of 20 days after transplantation for splenectomized patients, compared with 27.5 days for nonsplenectomized individuals (P=0.03). Increased risk of grade II-IV acute graft-versus-host disease (P=0.04) was noted in patients transplanted after splenectomy. Patients with MF received 0.264+/-0.189 U of packed red blood cells per day over the first 180 days after transplantation, and remained dependent on red blood cell transfusions for a median of 123 (IQR 48-205) days. Complete remission of MF was documented in 33% of evaluable patients. The 1 year cumulative nonrelapse mortality was 48.3%. Median survival for this group of patients was 393 (IQR 109-1014+) days, with a projected 2-year overall survival of 41%. We conclude that allogeneic SCT offers a reasonable chance for prolonged survival in patients with advanced MF, but this occurs at the cost of considerable toxicity and nonrelapse mortality.

Early-onset autoimmune hepatitis is associated with a C4A gene deletion

BACKGROUND

Autoimmune hepatitis is an immunologically mediated disorder with some similarities to systemic lupus erythematosus, including an association with HLA-A1, B8, DR3. This haplotype includes a C4A, 21-OHA gene deletion. Low serum levels of complement and C4 null alleles have been reported in autoimmune hepatitis, but studies have been at the protein level only.

METHODS

Twenty-four white patients with autoimmune hepatitis were studied by Southern blots using a C4A gene complementary DNA probe. HLA A, B, and C typing was determined using standard microcytotoxicity assays, and DR and DQ specificities were determined by restriction fragment length polymorphism analysis.

RESULTS

Thirteen of 24 patients had the C4A gene deletion compared with 12 of 90 controls. HLA-A1 and B8 were increased in patients with autoimmune hepatitis, as were HLA-DR3 (DR17), Dw24, DQ2. Patients with a C4A gene deletion presented at a younger age than those without the deletion and had significantly lower serum C3 and C4 levels. The C4A gene deletion was associated with HLA-A1, B8, DR3 in all but 1 patient who was HLA-DR3 negative.

CONCLUSIONS

A C4A gene deletion is found in patients with autoimmune hepatitis, especially those presenting at a young age. This complement gene deletion may be an important factor in the development of this disease.