Estimated read time: 5-6 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
[IN] HEA PUB MTC
TO HEALTH, MEDICAL, AND NATIONAL EDITORS:
Study Finds Pill May Represent Promising Treatment for Stubborn Blood
WASHINGTON, March 10, 2014 /PRNewswire-USNewswire/ -- A pill that
suppresses a key regulator of cancer growth may provide hope to
relapsed leukemia and lymphoma patients running out of treatment
options for their aggressive, treatment-resistant disease, according
to three reports* published online today in Blood, the journal of the
American Society of Hematology.
Patients with blood cancer are typically administered a combination of
chemotherapy and immunotherapy, the latter using the body's own immune
system to help fight disease, as a first line of treatment. While
chemotherapy has traditionally been successful in destroying cancer
cells, it is accompanied by many harmful side effects and patients
typically develop resistance, prompting researchers to investigate new
targeted therapies that may be able to block the production of cancer
cells while leaving normal cells unharmed.
One such targeted therapy, called idelalisib, is a highly selective
compound that, unlike chemotherapy, can target a specific mechanism
that fuels cancer growth. Taken as a pill, idelalisib first targets
and then blocks the expression of the delta isoform of the PI3 kinase
enzyme, which is critical for the activation and survival of cancerous
B cells. Idelalisib's narrow targeting of the PI3 kinase delta make it
an attractive potential therapy for patients with cancers that form in
the B-cell pathway such as chronic lymphocytic leukemia (CLL),
indolent non-Hodgkin lymphoma (iNHL), and mantle cell lymphoma (MCL).
While idelalisib is currently under review by the U.S. Food and Drug
Administration (FDA) for the treatment of treatment-resistant iNHL,
another drug in its class called ibrutinib, which specifically targets
a different cell regulator, has been approved as a second-line therapy
for CLL and MCL.
"Idelalisib is a part of a revolutionary new class of treatments that
can hone in on a specific target without causing the wide range of
side effects seen with chemotherapy," said study author Jennifer R.
Brown, MD, PhD, Director of the Chronic Lymphocytic Leukemia Center at
Dana-Farber Cancer Institute in Boston.
In three manuscripts published today in Blood, investigators present
data from a large Phase I study evaluating the safety and efficacy of
idelalisib in more than 150 patients with CLL, iNHL, and MCL. Before
joining the trial, patients had received several previous treatments -
some as many as 14 - that either failed to destroy the disease or
provided only a temporary reprieve. After an initial study involving
all trial participants, patients were separated into CLL, iNHL, and
MCL disease cohorts and received varied doses of idelalisib. The
therapy appeared to be effective, as patients suffered few side
effects and demonstrated promising response rates, with 72 percent of
CLL patients, 47 percent of iNHL patients, and 40 percent of MCL
patients achieving either a complete or partial response.
"Considering the high number of previous therapies that these patients
had received, higher than we sometimes see in comparable studies, the
efficacy of idelalisib that we observed was remarkable," said study
author Ian Flinn, MD, PhD, Director of the Hematologic Malignancies
Research Program at Sarah Cannon Research Institute in Nashville and a
widely recognized expert in lymphoma. "It was this initial excitement
that has inspired further studies of this therapy in patients with
treatment-resistant blood cancers."
While patients in the CLL and iNHL cohorts experienced significant and
prolonged reduction of disease activity, patients with MCL, a more
aggressive and treatment-resistant type of lymphoma, experienced less
favorable responses. Despite MCL patients' high overall response rate
of 40 percent to idelalisib, the duration of their response to the
drug was not as impressive; only a small fraction (22 enjoyed
prolonged benefits. Despite the modest duration of survival
facilitated by idelalisib in the MCL group, the strong response rate
suggests that investigators have identified a key regulator of cancer
growth; however, more research is needed to further understand the
potential of this therapy in MCL patients.
"While idelalisib is unlikely to receive designation as a single-agent
therapy in mantle cell lymphoma due to the short duration of response,
the path forward will likely include administering it in combination
with other agents or developing second-generation PI3 kinase
inhibitors," said study author Brad S. Kahl, MD, Director of the
Lymphoma Service at the University of Wisconsin Carbone Cancer Center
in Madison. "This study offers a strong foundation for future research
on idelalisib in this disease."
*Studies referenced in this release include:
Idelalisib, an Inhibitor of Phosphatidylinositol 3-Kinase p110?, for
relapsed/refractory chronic lymphocytic leukemia, Brown et al.
Idelalisib, a selective inhibitor of phosphatidylinositol 3-kinase-?,
as therapy for previously treated indolent non-Hodgkin lymphoma, Flinn
Results of a phase I study of idelalisib, a PI3K? inhibitor, in
patients with relapsed or refractory mantle cell lymphoma (MCL), Kahl
Blood (www.bloodjournal.org), the most cited peer-reviewed publication
in the field of hematology, is available weekly in print and online.
Blood is the official journal of the American Society of Hematology
(ASH) (www.hematology.org), the world's largest professional society
concerned with the causes and treatment of blood disorders.
ASH's mission is to further the understanding, diagnosis, treatment,
and prevention of disorders affecting blood, bone marrow, and the
immunologic, hemostatic, and vascular systems by promoting research,
clinical care, education, training, and advocacy in hematology.
blood@ is a registered trademark of the American Society of
SOURCE American Society of Hematology
/CONTACT: Amanda Szabo, firstname.lastname@example.org; 202-552-4914
/Web Site: http://www.hematology.org
CO: American Society of Hematology
ST: District of Columbia
IN: HEA PUB MTC
-- DC79927 --
0000 03/10/2014 14:06:00 EDT http://www.prnewswire.com
Copyright © The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.