SOUTH SAN FRANCISCO, Calif., June 16 /PRNewswire-FirstCall/ -- Sunesis
Pharmaceuticals, Inc. (Nasdaq: SNSS) presented data Saturday from two clinical
trials of the company's lead drug candidate, voreloxin (formerly SNS-595),
including updated results of a Phase 1 trial of voreloxin when used as a
single agent in relapsed or refractory patients with acute myeloid leukemia
(AML) and preliminary data from a Phase 1b trial of voreloxin in combination
with cytarabine in patients with relapsed/refractory AML.
"Voreloxin has demonstrated anti-leukemic activity as a single agent and
is showing encouraging early response data when administered in combination
with cytarabine. Importantly, it has also been generally well tolerated, even
among patients older than 60 and patients with AML with poor risk features,"
said Judith E. Karp, M.D., Director, Adult Leukemia Program at The Sidney
Kimmel Comprehensive Cancer Center at Johns Hopkins University and an
investigator for the Phase 1 and Phase 1b clinical trials of voreloxin in AML.
"Voreloxin appears to be a promising new drug for the treatment of AML and I
look forward to the results of continued clinical investigation."
Analysis of Safety and Response Data for Older AML Patients Supports Phase
2 REVEAL-1 Trial
Researchers presented an analysis of comparative safety, pharmacokinetic
and response data from Sunesis' Phase 1 dose-escalating trial of single-agent
voreloxin comparing results from older patients (age >/= 60) with those from
younger patients (age < 60). Overall, voreloxin demonstrates a similar safety
profile in both older and younger patients. In the Phase 1 trial, voreloxin
was administered on a weekly or twice-weekly schedule and patient demographics
were similar between the two treatment schedules. Six patients, including
four age 60 or older and two younger than age 60, achieved complete remission
(CR) or complete remission without platelet recovery (CRp) or complete
remission with incomplete recovery of hematopoeitic elements (CRi) when
voreloxin was administered at doses of 50 mg/m2 or greater weekly or 40 mg/m2
twice-weekly. Duration of complete remissions (CR or CRp) was reported.
Remissions of up to seven months have been observed thus far, with two
patients undergoing reinduction with voreloxin following relapse.
Sixty-eight patients were evaluable for safety, with 42 patients ranging
in age from 60-85 years old and 26 patients age 21-59 years. Voreloxin was
generally well tolerated in both the older and younger patient subgroups with
similar incidence of Grade 3-4 adverse events. The dose-limiting toxicity was
reversible oral mucositis, and a maximum-tolerated dose of 72 mg/m2
once-weekly and 40 mg/m2 twice-weekly was established. Researchers also
reported that voreloxin pharmacokinetics were not influenced by age.
"AML is primarily a disease of the elderly and the medical need for new
agents that can be tolerated by older patients remains unmet. Results from
our comparative analysis demonstrate that voreloxin is generally well
tolerated and achieves anti-leukemic activity among older, advanced AML
patients, supporting our strategy for progressing the clinical development of
voreloxin in this indication," said Glenn Michelson, M.D., Vice President,
Clinical Strategy at Sunesis. "Sunesis recently initiated the Phase 2
REVEAL-1 (Response Evaluation of Voreloxin in Elderly AML) clinical trial to
evaluate voreloxin in newly diagnosed AML in elderly patients. We hope to
present initial data from the REVEAL-1 trial later this year."
Preliminary Data from Phase 1b Study of Voreloxin and Cytarabine Indicates
Activity of Combination Regimen
Preliminary results were also presented today from Sunesis' ongoing
dose-escalating Phase 1b clinical trial evaluating voreloxin in combination
with cytarabine, the current standard of care in patients with relapsed and/or
refractory AML. The Phase 1b trial is designed to evaluate the safety and
tolerability, and to provide a preliminary assessment of anti-leukemic
activity, of escalating doses of voreloxin when administered on days one and
four with a fixed dose of 400 mg/m2/day of cytarabine given as a continuous
infusion for five days. Of twelve evaluable patients in the first three
cohorts, three patients have achieved CRs (one at 20 mg/m2 of voreloxin and
two at 34 mg/m2 of voreloxin). Six patients were enrolled in cohort 4 (50
mg/m2 of voreloxin), and no dose limiting toxicities have been observed thus
far at this dose. Patients are now being enrolled in cohort 5 at 70 mg/m2 of
voreloxin. Voreloxin pharmacokinetics have so far been unaffected by the
combination with cytarabine.
"We are very pleased by the interim results reported today from our Phase
1b combination study of voreloxin with cytarabine. We look forward to
reporting results from this study later in the year, including CR rates at 50
mg/m2 and higher dose levels of voreloxin," continued Dr. Michelson.
These data were presented today in a poster titled "Safety and Efficacy
Experience of Voreloxin (formerly SNS-595) in Relapsed/Refractory Acute
Leukemia Patients >/= 60 Years Old Compared to <60 Years Old: Results of a
Phase 1b Study" (Abstract #0515) at the 13th Congress of the European
Hematology Association. A copy of the poster will be available on the Sunesis
corporate website at http://www.sunesis.com.
About Voreloxin (formerly SNS-595)
Sunesis' lead compound, voreloxin (formerly SNS-595), is a novel
naphthyridine analog, structurally related to quinolones, a class of compounds
which has not been used previously for the treatment of cancer. Voreloxin
both intercalates DNA and inhibits topoisomerase II, resulting in
replication-dependent, site-selective DNA damage, irreversible G2 arrest and
rapid apoptosis. Voreloxin is currently being evaluated as a single agent in
a Phase 2 clinical trial (known as the REVEAL-1 trial) in previously untreated
elderly AML patients, in a Phase 1b clinical trial combining voreloxin with
cytarabine for the treatment of patients with relapsed/refractory AML, and as
a single agent in a Phase 2 clinical trial in platinum-resistant ovarian
cancer. In clinical trials conducted to date, voreloxin has been generally
well tolerated and has shown objective responses in both solid and hematologic
tumor types.
About Acute Myeloid Leukemia
AML is a rapidly progressing cancer of the blood characterized by the
uncontrolled proliferation of immature blast cells in the bone marrow. The
Leukemia and Lymphoma Society estimates that over 13,000 new cases of AML were
diagnosed and approximately 9,000 deaths from AML occurred in the U.S. during
2007. AML is generally a disease of older adults and the median age of a
patient diagnosed with AML is about 67 years. A majority of elderly patients
are not considered candidates for standard induction therapy or decline
therapy, resulting in an acute need for new treatment options.
About Sunesis Pharmaceuticals
Sunesis is a clinical-stage biopharmaceutical company focused on the
development of new oncology therapeutics for the treatment of solid and
hematologic cancers. Sunesis has built a highly experienced cancer drug
development organization committed to advancing its lead product candidate,
voreloxin, in multiple indications to improve the lives of people with cancer.
For additional information on Sunesis Pharmaceuticals, please visit
http://www.sunesis.com.
SUNESIS and the logo are trademarks of Sunesis Pharmaceuticals, Inc.
Safe Harbor Statement
This press release contains forward-looking statements including without
limitation statements related to the potential safety, efficacy, duration of
response and commercial potential of voreloxin (formerly SNS-595); planned
additional clinical testing and development efforts for voreloxin; the timing
of enrollment in the ongoing clinical trials of voreloxin; and the timing of
announcements of results of ongoing clinical trials of voreloxin. Words such
as "promising," "encouraging," "hope," "appears," "demonstrate," "indicates,"
"supports," and "look forward" and similar expressions are intended to
identify forward-looking statements. These forward-looking statements are
based upon Sunesis' current expectations. Forward-looking statements involve
risks and uncertainties. Sunesis' 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, the risk that Sunesis' development activities for
voreloxin, including enrollment and reporting of results, could be halted
significantly or delayed for various reasons; the risk that Sunesis' clinical
trials for voreloxin may not demonstrate safety or efficacy or lead to
regulatory approval; the risk that preliminary data and trends including data
regarding duration of response, may not be predictive of future data or
results; the risk that Sunesis' preclinical studies and clinical trials may
not satisfy the requirements of the FDA or other regulatory agencies; risks
related to the conduct of Sunesis' clinical trials and manufacturing; and
risks related to Sunesis' need for additional funding. These and other risk
factors are discussed under "Risk Factors" and elsewhere in Sunesis' Annual
Report on Form 10-K for the year ended December 31, 2007, Sunesis' Quarterly
Report on Form 10-Q for the quarter ended March 31, 2008 and other filings
with the Securities and Exchange Commission. Sunesis expressly disclaims any
obligation or undertaking to release publicly any updates or revisions to any
forward-looking statements contained herein to reflect any change in the
company's expectations with regard thereto or any change in events, conditions
or circumstances on which any such statements are based.
SOURCE Sunesis Pharmaceuticals, Inc.
