EXTRA! EXTRA!
April 8, 2013 it was
announced that the FDA granted breakthrough therapy designation for ibrutinib
(Janssen and Pharmacyclics) as a monotherapy for patients with CLL/SLL (chronic
lymphocytic leukemia or small lymphocytic lymphoma) with deletion of the short
arm of chromosome 17. This genetic mutation is associated with poor prognosis
and is one of the worst prognostic
factors in patients with CLL. This is what I have.
This is the third
breakthrough designation the FDA granted for ibrutinib an investigational
Bruton’s tyrosine kinase inhibitor. One was as a monotherapy for previously
treated patients with relapsed or refractory mantle cell lymphoma, and the
other was as a monotherapy for patients with Waldenström’s macroglobulinemia.
The breakthrough therapy
designation was created in 2012. It enables the development and review of drugs
shown in preclinical studies to offer potentially substantial improvements over
existing therapies for patients with serious or life-threatening diseases to be
expedited.
Patients like me with 17p
deletion generally do not respond well to chemoimmunotherapy, and are limited
on their treatment options. In my case, because I am bi-racial, I have less
than a 1% chance of finding a bone marrow donor match. Ibrutinib has the
potential to improve the outcome in this serious and life-threatening disease,
and is much less risky than a bone marrow transplant.
A Phase II global study of
ibrutinib in patients with CLL deletion 17p, will be available this year and
Pharmacyclics plans to enroll 111 patients worldwide. The study called
“RESONATE™ -17” is a single-arm, open-label, multi-center trial using ibrutinib
as a monotherapy in previously-treated patients who have deletion 17p, who did
not respond or who relapsed (a high unmet need population). The purpose of the
study will be to determine overall response rate.
Those of you following
my blog know that I have just completed my 9-month milestone as “a little white
laboratory mouse” in the clinical trial with ibrutinib. Dr. Adrian Wiestner,
M.D., PhD, of the National Institutes of Health is the lead investigator in the
clinical study. Dr. Wiestner just presented the findings from this clinical
trial at the American Association for Cancer Research (AACR) in Washington,
D.C. Here is an excerpt from Pharmacyclics’ press release from April 8, 2013.
Please note that this is a fast track to FDA approval, and applies to 17p
deleted CLL/SLL patients like me. :-)
Phase II Ibrutinib
Monotherapy Study Shows CLL Patients Achieved Rapid and Sustainable Disease
Control Irrespective of Age or High Risk Prognostic Factor
SUNNYVALE, Calif., April
8, 2013 /PRNewswire/ -- Pharmacyclics, Inc. (Nasdaq: PCYC) today announced
results from a Phase II trial of the investigational oral agent ibrutinib which
demonstrated rapid and sustained disease control as a monotherapy in untreated,
relapsed and refractory chronic lymphocytic leukemia (CLL) patients,
irrespective of characteristics that predict poor outcomes to
chemoimmunotherapy.
This study was discussed
at today's American Association for Cancer Research (AACR) annual meeting in
Washington, DC together in addition to 8 other presentations covering advances
in clinical and pre-clinical research with ibrutinib. The Phase II study, which
was sponsored by the National Heart, Lung and Blood Institute, included an
analysis of two CLL patient cohorts: the elderly, above 65 years of age, (n=24,
of which 8 were treatment naive) and the high risk genetic group with a
deletion of chromosome 17p (del 17p) (n=29, of which 15 were treatment naive).
Many elderly patients with CLL are unable to tolerate aggressive therapies.
Patients with deletion of chromosome 17p typically are poor responders to
chemoimmunotherapy and have limited treatment options with no standard of care
defined. Of all CLL patients enrolled in this trial, 72% had been characterized
as Rai stage 3-4, indicating an advance stage, high-risk patient population.
The results of the study
were presented by lead investigator Adrian Wiestner, M.D., PhD, Hematology Branch, NHLBI, National
Institutes of Health. "Ibrutinib was highly efficacious as a single agent
in patients with untreated, relapsed and unresponsive CLL, irrespective of
their del 17p status," Dr. Wiestner said. "Responses in this study
appear to be durable, and results indicate the drug is effective against the
disease in lymph nodes, spleen and bone marrow. This is important because
existing therapies often fail to effectively eliminate cancer cells in these
tissue sites. Targeted therapy for CLL is becoming a reality, and this new
approach may greatly improve the lives of patients with this disease."
The study also evaluated
in vivo effects of ibrutinib using blood and tissue samples collected before
and during treatment. Ibrutinib demonstrated rapid and sustained disease
control in blood, lymph nodes, spleen and bone marrow. After 6 months, 95
percent of patients experienced a reduction in lymph node size and all showed
reduction in spleen enlargement, with a median reduction of 55 percent. In 26
patients, for whom a bone marrow biopsy was done, tumor infiltration decreased
by 82 percent.
The Progression Free
Survival probability for these patients at 12 months was estimated to be 94
percent. Most adverse events were mild and manageable and included diarrhea,
fatigue and rash, severe events occurred in less than 13 percent of
patients.
"We are very pleased
with the continued research that is being demonstrated at AACR across 9
different presentations. These advances show the potential breadth of the
ibrutinib program and provide further opportunities for us to pursue. We are
grateful for the continued support of our collaborators, investigators,
patients and shareholders," said Bob Duggan, CEO and chairman of the
board.
Ibrutinib has been
designated as a FDA Breakthrough Therapy in CLL patients with deletion 17p, based on data from completed Phase I/II clinical
studies, where ibrutinib as a monotherapy was used to treat patients with this
disease. Ibrutinib has the potential to improve the outcome in this serious and
life-threatening disease, and may provide a substantial improvement over
existing therapies for this indication.