American Society of Hematology, Dec. 4-7, 2010
The 52nd Annual Meeting and Exposition of the American Society of Hematology took place Dec. 4 to 7 in Orlando, Fla., and attracted over 21,000 participants. The conference highlighted recent advances in the diagnosis, prevention, and treatment of hematologic disorders, with presentations focusing on understanding the underlying mechanisms of leukemia, lymphoma, and other hematologic malignancies as well as novel treatment approaches for other hematologic disorders such as sickle cell anemia, hemophilia B, and Wiskott-Aldrich Syndrome.
In one study, Andrew M. Davidoff, M.D., of the St. Jude Children's Research Hospital and the University of Tennessee Health Science Center in Memphis, and colleagues developed a novel gene therapy approach for the treatment of hemophilia B, which is a disease that results from a deficiency in clotting Factor IX.
"We aimed to replace the Factor IX gene using adeno-associated virus as the delivery vector. This has been tried before but was not effective. However, we have modified the vector in several ways in order to make it more effective and successfully increased the level of Factor IX in patients with Hemophilia B," Davidoff said.
The investigators administered the novel vector to four patients and followed them for Factor IX expression and potential toxicity, including liver injury.
"We plan to evaluate three doses of vector -- low, intermediate, and high. We have just completed evaluating the low and immediate doses of vector in four patients, two receiving each of the vector doses; we are now going to look at the higher vector dose. In all four patients, we found no toxicity. In addition, two patients had detectable levels of Factor IX -- one in the low group and one in the intermediate group," Davidoff added. "Our early results are encouraging that this approach will be a safe and effective way to treat patients with hemophilia B, but further testing is required."
One or more co-authors disclosed financial relationships with Genzyme Inc., Third Rock Ventures, Novo-Nordisk, and Shire Inc.
In another study, Christoph Klein, M.D., Ph.D., of Hannover Medical School in Germany, and colleagues found a marked clinical improvement among patients with Wiskott-Aldrich syndrome after stem cell transplantation.
"Specifically, we found that nine of 10 patients had a reconstitution in their immune function and stopped bleeding. However, one patient experienced a failure, as the patient did not receive enough stem cells. The rest of the patients who received enough stem cells experienced robust immunity," Klein said.
However, more recently, one patient became ill with lymphoblastic leukemia, which the investigators believe was related to stem cell therapy, primarily due to the vector used. The investigators are currently attempting to improve the vector technology to reduce this risk in future trials without losing efficacy, according to Klein.
"Overall, this study confirms the markedly robust clinical benefit of stem cell therapy in these patients, but caution needs to be taken due to the risk of adverse events such as lymphoblastic leukemia. This clinical study proves that gene therapy can help patients with Wiskott-Aldrich syndrome and thus offers hope for patients and families affected by a deadly disease," Klein added.
Jonathan Michael Flanagan, Ph.D., of the St. Jude Children's Research Hospital in Memphis, Tenn., and colleagues identified genetic biomarkers that may serve as indicators of whether children with sickle cell anemia are at a higher risk of developing stroke.
"We identified five different polymorphisms in four different genes associated with stroke, with one being protective and the other three serving as risk factors for stroke. In addition, the α-thalassemia trait was associated with protection against stroke," Flanagan said. "The genes we identified appear to have a feasible role in stroke development. We hope to expand this list of candidate genes in a genome-wide association study to establish a comprehensive list of all genes with a significant impact on development of cerebrovascular disease in sickle cell anemia. We hope that eventually these genetic modifiers may be used as prognostic predictive biomarkers of stroke in concert with existing clinical tests."
ASH: Stem Cell Donation Does Not Up Overall Cancer Risk
TUESDAY, Dec. 7 (HealthDay News) -- Individuals who donate peripheral blood stem cells (PBSCs) or bone marrow do not appear to be at an overall increased risk of cancer, according to research being presented at the annual meeting of the American Society of Hematology, held from Dec. 4 to 7 in Orlando, Fla. According to another study, acute myeloid or lymphoblastic leukemia patients who receive double unrelated cord blood transplants may experience better overall outcomes than those who receive single cord blood transplants. Other studies being presented address stem cell transplant procedures in treating various hematologic malignancies and highlight zoledronic acid's ability to improve survival in multiple myeloma patients.
ASH: Novel Therapies Improve Leukemia Outcomes
MONDAY, Dec. 6 (HealthDay News) -- Nilotinib may improve survival in some chronic myeloid leukemia (CML) patients, and patients with various types of CML respond well to ponatinib, according to research being presented at the annual meeting of the American Society of Hematology, held from Dec. 4 to 7 in Orlando, Fla. Other studies being presented outline the optimal use of imatinib, address how a new gene target functions for several myeloid malignancies, highlight a tool for predicting acute myeloid leukemia outcomes, and address the use of mitoxantrone in acute lymphoblastic leukemia (ALL).
ASH: New Lymphoma Treatment Options Promising
MONDAY, Dec. 6 (HealthDay News) -- Rituximab may be a better option than watchful waiting in some lymphoma patients, and a new treatment option appears effective for relapsed or refractory Hodgkin's lymphoma, according to two studies being presented at the annual meeting of the American Society of Hematology, held from Dec. 4 to 7 in Orlando, Fla. Other research being presented will highlight new options for the standard treatment of advanced asymptomatic follicular lymphoma; mantle cell lymphoma; and early, unfavorable Hodgkin's disease.
ASH: Risk-Prediction Models Aid Thromboembolism Treatment
MONDAY, Dec. 6 (HealthDay News) -- New treatment options for patients with venous thromboembolism (VTE) appear promising, and risk-prediction models may be useful for clinical practice management of these patients, according to research being presented at the annual meeting of the American Society of Hematology, held from Dec. 4 to 7 in Orlando, Fla.
ASH: Oral Venous Thrombosis Agent Effective and Safe
MONDAY, Dec. 6 (HealthDay News) -- Rivaroxaban, an oral factor Xa inhibitor, may provide clinical practitioners with a simple, fixed-dosed regimen for the short-term and continued treatment of deep-vein thrombosis (DVT), according to a study published online Dec. 4 in the New England Journal of Medicine to coincide with presentation at the annual meeting of the American Society of Hematology, held from Dec. 4 to 7 in Orlando, Fla.