14.7 months median progression free survival
28% confirmed partial response rate & 72% disease control rate at
week 16
SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Feb. 3, 2012--
Exelixis, Inc. (NASDAQ:EXEL) today reported preliminary data from a
cohort of heavily pretreated patients with metastatic refractory renal
cell carcinoma (RCC) participating in an ongoing phase 1b trial of
cabozantinib. Toni K. Choueiri, M.D., Director of the Kidney Cancer
Center at the Dana-Farber Cancer Institute, will present the data
(Abstract #364) in a poster session at the 2012 Genitourinary Cancers
Symposium at 6:45 a.m. PST tomorrow in San Francisco.
As of the January 18, 2012 data cut-off, 25 RCC patients were enrolled
with 88% having received prior anti-VEGF therapy, 60% having received
prior mTOR inhibitor therapy, and 52% having received ≥1 anti-VEGF and 1
mTOR therapy. Sixty-four percent of patients received ≥ 2 prior
anti-cancer agents. Tumor regression was observed in 19 of 21 patients
(90%) with ≥1 post-baseline assessment. Best overall response was
determined per RECIST criteria with 7 of 25 patients (28%) showing a
confirmed partial response (PR). Importantly, PRs were observed in
heavily pretreated patients, including 3 patients with 2-4 prior
systemic therapies, and 2 patients with >4 prior systemic therapies.
Thirteen additional patients (52%) had stable disease (SD) as their best
response, and only a single patient (4%) demonstrated evidence of
primary refractoriness to cabozantinib with a best overall response of
progressive disease. The rate of disease control (PR + SD) at week 16
for all 25 patients is 72%. Kaplan Meier estimate of median
progression-free survival is 14.7 months (95% CI, lower limit 7.3 months
– upper limit not reached). Ten patients remain on study and progression
free with treatment durations ranging up to 16.4 months.
One patient with symptomatic bone metastases was followed by bone scan.
A partial bone scan resolution was observed at week 7 in this patient
who had previously been treated with sorafenib, sunitinib, and
everolimus. The patient also substantially reduced narcotic use by week
7 and continued on reduced narcotics until week 25. A second patient
with bone metastases and bone pain at baseline reported complete
resolution of pain by week 4 and remains pain free at week 73.
The data presented are from a cohort of 25 RCC patients enrolled in an
ongoing phase 1b drug interaction study of cabozantinib in patients with
advanced solid tumors. Patients in this trial receive 140 mg of oral
cabozantinib administered daily, and the study endpoints are safety,
tolerability, and anti-tumor activity. The RCC patients had
histologically confirmed RCC (with clear cell components) and
metastases, were refractory to or had progressed following standard
therapy, and had measurable disease per RECIST. Bone metastases were
present at baseline in 4 patients (16%), one of whom was followed by
bone scan.
“The high rate of durable tumor response, very low rate of primary
refractoriness to drug therapy, and the long median progression-free
survival observed in these heavily pretreated RCC patients are very
encouraging,” said Michael M. Morrissey, Ph.D., president and chief
executive officer of Exelixis. “Additionally, the bone scan response and
reduction in narcotic usage in two of the four patients with bone
metastases are consistent with the positive effects that we have
observed for cabozantinib with respect to bone lesions in patients with
castration-resistant prostate cancer and metastatic breast cancer. The
data presented today support continued study of cabozantinib in patients
with advanced RCC, and we hope to pursue such studies as part of our
recently announced Cooperative Research and Development Agreement with
the National Cancer Institute’s Cancer Therapy and Evaluation Program.”
No new safety signals were observed. The most frequently reported grade
≥ 3 adverse events (AEs), regardless of causality were: hypophosphatemia
(36%), hyponatremia (20%), both manageable with substitution with or
without cabozantinib dose reduction or interruption, fatigue (16%),
diarrhea (12%), proteinuria (8%), palmar-plantar erythrodyesthesia (4%),
and vomiting (4%).
“These data indicate that cabozantinib can provide clinical benefit to
patients with advanced RCC, including those who have received anti-VEGF
therapy, anti-mTOR therapy, or a sequence of these targeted therapies,”
said Dr. Choueiri. “While anti-VEGF and anti-mTOR therapies have
advanced the treatment of RCC, many patients are refractory to these
agents and experience disease progression. Dual inhibition of both
VEGFR2 and MET by cabozantinib may provide an alternative or additional
mechanism for controlling disease in these patients, and further study
of cabozantinib in this indication is warranted.”
The clinical data poster mentioned in this press release will be
available at www.exelixis.com
commencing at 6:00 a.m. EST today.
About Cabozantinib
Cabozantinib is a potent, dual inhibitor of MET and VEGFR2. Cabozantinib
is an investigational agent that provides coordinated inhibition of
metastasis and angiogenesis to kill tumor cells while blocking their
escape pathways. The therapeutic role of cabozantinib is currently being
investigated across several tumor types. MET is upregulated in many
tumor types, thus facilitating tumor cell escape by promoting the
formation of more aggressive phenotypes, resulting in metastasis.
MET-driven metastasis may be further stimulated by hypoxic conditions in
the tumor environment, which are often exacerbated by selective
VEGF-pathway inhibitors. The vast majority of RCC cases have an
inactivation of the von Hippel-Lindau tumor suppressor gene, which
mimics a hypoxic state and triggers upregulation of both VEGF and MET
expression. In preclinical studies, cabozantinib has shown powerful
tumoricidal, antimetastatic and antiangiogenic effects, including:
-
Extensive apoptosis of malignant cells
-
Decreased tumor invasiveness and metastasis
-
Decreased tumor and endothelial cell proliferation
-
Blockade of metastatic bone lesion progression
-
Disruption of tumor vasculature
About Exelixis
Exelixis, Inc. is a biotechnology company committed to developing small
molecule therapeutics for the treatment of cancer. Exelixis is focusing
its proprietary resources and development efforts exclusively on
cabozantinib, its most advanced solely-owned product candidate, in order
to maximize the therapeutic and commercial potential of this compound.
Exelixis believes cabozantinib has the potential to be a high-quality,
differentiated pharmaceutical product that can make a meaningful
difference in the lives of patients. Exelixis has also established a
portfolio of other novel compounds that it believes have the potential
to address serious unmet medical needs. For more information, please
visit the company's web site at www.exelixis.com.
Forward-Looking Statements
This press release contains forward-looking statements, including,
without limitation, statements related to: the continued development and
clinical, therapeutic and commercial potential of, and opportunities
for, cabozantinib; the belief that the referenced data is encouraging
and warrant further study of cabozantinib in patients with RCC; the hope
to study cabozantinib further in RCC; the potential clinical utility of
cabozantinib in RCC; the belief that cabozantinib can provide clinical
belief to patients with advanced RCC; and the belief that dual
inhibition of both VEGFR2 and MET by cabozantinib may provide an
alternative or additional mechanism for controlling disease in RCC
patients.
Words such as “encouraging,” “support,” “hope,” “indicate,” “can,”
“may,” “warranted,” “believes,” “potential,” and similar expressions are
intended to identify forward-looking statements. These forward-looking
statements are based upon Exelixis' current plans, assumptions, beliefs
and expectations. Forward-looking statements involve risks and
uncertainties. Exelixis' actual results and the timing of events could
differ materially from those anticipated in such forward-looking
statements as a result of these risks and uncertainties, which include,
without limitation: risks related to the potential failure of
cabozantinib to demonstrate safety and efficacy in clinical testing;
Exelixis' ability to conduct clinical trials of cabozantinib sufficient
to achieve a positive completion; the sufficiency of Exelixis' capital
and other resources; the uncertain timing and level of expenses
associated with the development of cabozantinib; the uncertainty of the
FDA approval process; market competition; and changes in economic and
business conditions. These and other risk factors are discussed under
"Risk Factors" and elsewhere in Exelixis' quarterly report on Form 10-Q
for the quarter ended September 30, 2011 and Exelixis' other filings
with the Securities and Exchange Commission. Exelixis expressly
disclaims any duty, obligation or undertaking to release publicly any
updates or revisions to any forward-looking statements contained herein
to reflect any change in Exelixis' expectations with regard thereto or
any change in events, conditions or circumstances on which any such
statements are based.

Source: Exelixis, Inc.
Exelixis, Inc.
Charles Butler, 650-837-7277
Vice
President,
Investor Relations and
Corporate
Communications
cbutler@exelixis.com