NEW ORLEANS, Dec. 8, 2013 /PRNewswire-USNewswire/ -- Several new, targeted therapies show promise to expand treatment options for chronic lymphocytic leukemia (CLL) and are more effective and better tolerated than standard chemotherapy, according to studies presented today during the 55th American Society of Hematology Annual Meeting and Exposition in New Orleans.
CLL is a blood cancer that occurs when abnormal white blood cells called lymphocytes accumulate in the blood, bone marrow, and lymph nodes or other organs, causing these organs to enlarge. Approximately 15,000 Americans are diagnosed with CLL every year, and nearly 70 percent of those affected are 65 or older. For some patients with a slower progressing disease, many physicians employ "watch and wait" strategies to minimize unnecessary toxic treatments. However, patients with high -risk features or a more rapidly progressing disease require prompt treatment.
While the current standard chemotherapy -based treatment regimen for patients with CLL has been effective in improving outcomes for these patients, it remains highly toxic, prompting additional research to identify strategies to further reduce the treatment burden. Newer drugs that more precisely target pathways and proteins known to trigger CLL development, and leave normal cells unharmed, are proving to be more effective in promoting cancer cell death while safer for the patient. Four studies presented today reveal data on the performance of several new CLL therapies that demonstrate potent effects on key regulators of cancer cell behavior.
"These exciting developments in CLL therapy represent a shift toward treatments that hone in on specific regulators of cancer, ultimately providing a safer and more effective treatment regimen," said Jennifer R. Brown, MD, PhD, Director of the Chronic Lymphocytic Leukemia Center at Dana -Farber Cancer Institute in Boston. "These data give us even more reason to believe that the future outlook for CLL patients is bright."This press conference will take place on Sunday, December 8, 2013, at 9:30 a.m. CST. Head-To-Head Comparison of Obinutuzumab (GA101) Plus Chlorambucil (Clb) Versus Rituximab Plus Clb in Patients With Chronic Lymphocytic Leukemia (CLL) and Co-Existing Medical Conditions (Comorbidities): Final Stage II Results of the CLL11 Trial [ 6 ] A commonly used combination treatment for CLL today consists of chemotherapy and rituximab, a synthetic molecule engineered to target a protein on the surface of CLL cells (CD20). While effective, rituximab has less potency in CLL than in other cancers, and chemotherapy used in combination with rituximab may not be well tolerated among elderly patients. In an effort to improve treatment options for CLL patients, investigators conducted a head -to -head comparison of rituximab and obinutuzumab (GA101), a novel monoclonal antibody engineered to attack CD20, but hypothesized to have more potent anti -leukemic effects. To test their hypothesis, investigators enrolled 781 patients (average age 73) and split them into three treatment arms: one arm received GA101 in combination with the standard chemotherapy chlorambucil (Clb; GClb, n=333), a second arm received rituximab and Clb (RClb, n=330), and a third arm received Clb alone (n=118). In combination with Clb, GA101 demonstrated more anti -leukemic activity than rituximab, leading to a statistically significant and clinically meaningful prolongation of the median progression -free survival (26.7 months in the GClb arm and 15.2 months in the RClb arm) as well as a higher overall response rate (78% GClb vs. 65% RClb) with acceptable toxicity and no added risk of infection. "Our results suggest that GA101 may be a stronger CD20 antibody than rituximab. This could lead to a potential decrease in the total amount of chemotherapy required for an effective combination regimen, translating to less toxicity for the patient," said study author Valentin Goede, MD, of University Hospital Cologne in Germany. "While we will continue to evaluate these results through a longer follow-up period, these findings suggest that GA101 has the potential to eventually replace rituximab for the care of CLL patients." Dr. Goede will present this study during the Plenary Scientific Session 4:15 p.m. CST on Sunday, December 8, 2013, in Hall F of the Ernest N. Morial Convention Center. A Phase III, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Efficacy and Safety of Idelalisib and Rituximab for Previously Treated Patients with Chronic Lymphocytic Leukemia (CLL) [ LBA-6 ] This study presents results of a Phase III clinical trial of a new, first-in-class oral kinase inhibitor, called idelalisib, for patients with chronic lymphocytic leukemia (CLL) who have already received other standard treatments for their disease and were not considered candidates for additional chemotherapy. This highly selective compound targets the delta isoform of the PI3 kinase enzyme, which is critical for the activation and survival of CLL cells and other low-grade B cell lymphomas. To better gauge the drug's safety and efficacy, investigators randomized 220 adult CLL patients to receive a combination of either idelalisib twice daily and rituximab or placebo twice daily and rituximab (the control arm) continuously through disease progression or death.