Cell Therapeutics, Inc. (CTI) announced the publication of results from its
randomized phase III trial comparing OPAXIO(TM) (paclitaxel poliglumex,
CT-2103) with gemcitabine or vinorelbine for the treatment of PS 2
(performance status 2) patients with previously untreated non-small cell
lung cancer (NSCLC) in the Journal of Thoracic Oncology (Volume 3, Number
7, July 2008). Results showed that overall survival was similar between the
two arms (hazard ratio of 0.95; OPAXIO to control).
Patients treated with
OPAXIO required less supportive care including fewer red blood cell
transfusions, hematopoietic growth factors, and opioid analgesics than
those patients receiving either gemcitabine or vinorelbine. There were
relatively few non-hematopoietic grade 3 or 4 toxicities in either arm.
Additionally, patients receiving OPAXIO required fewer clinic visits due to
its administration schedule, once every three weeks, and short infusion
time, compared to patients receiving either gemcitabine or vinorelbine.
The objective of the study, known as STELLAR 4, was to determine if
OPAXIO would improve overall survival when compared with the standard
single-agent treatments of gemcitabine or vinorelbine in PS 2 patients with
advanced NSCLC who had not previously received chemotherapy. The trial did
not meet the primary endpoint. Secondary objectives of the study included
measuring the efficacy and safety of the treatments. OPAXIO did demonstrate
similar overall survival and a reduction in the supportive care required by
patients.
A total of 190 patients with advanced NSCLC were randomized to the
comparator arm; 191 were randomized to the OPAXIO arm with a dosage of 175
mg/m^2, and 96 were randomized to the OPAXIO arm at a dosage of 235 mg/m^2.
The OPAXIO dose was reduced to 175 mg/m^2 after 96 patients had been
treated, because the Data Monitoring Committee noted an increase in deaths
associated with neutropenia in patients who had received the 235 mg/m^2
dosage. The following data refers to those patients treated at the OPAXIO
dose of 175 mg/m^2. The median number of cycles administered was 4, with a
median of 3.5 in the control arm.
A total of 754 cycles of OPAXIO were
administered, and 652 cycles were administered in the comparator arm. More
patients in the OPAXIO arm received 6 cycles of treatment (38 percent
versus 23 percent; p = 0.002). Progressive disease was the most common
reason for not completing 6 cycles (55 percent in the OPAXIO arm and 59
percent in the comparator arm). Fewer OPAXIO patients (12 percent)
discontinued treatment as a result of adverse events, compared to 17
percent of patients in the control arm. Survival, time to progression
(TTP), and response rates were similar in both arms. Median overall
survival was 7.3 months in the OPAXIO arm and 6.6 months in the control
arm. The estimated 1-year survival rate was the same in both arms (26
percent), and the approximate 2-year survival rate was numerically higher
in the OPAXIO arm (15 percent) than the comparator arm (10 percent). There
was a lower requirement for red blood cell transfusions (p = 0.001),
erythropoietin use (p = 0.014), myeloid growth factors (p = 0.032), and new
narcotic analgesics (p = 0.034) in the OPAXIO arm when compared to the
control arm. No significant differences were evident in quality of life
based on FACT-LCS evaluations between the two arms. OPAXIO patients
experienced fewer hematologic (p
Details of the Study
The phase III trial, reported by Mary E. R. O'Brien, M.D., F.R.C.P., et
al, of the Royal Marsden Hospital and the Kent Cancer Centre in Surrey, UK,
was a randomized, multi-center trial. The trial was conducted at 83 centers
in ten countries, and randomized on a 1:1 ratio to evaluate the efficacy
and safety of this regimen in patients with chemotherapy-naïve NSCLC.
Patients with advanced stage IIIb/IV NSCLC and PS 2 were treated with
OPAXIO on day 1 of a 21-day cycle, while patients receiving gemcitabine
were treated on days 1, 8, and 15 of each 28-day cycle. Vinorelbine was
administered on days 1, 8, and 15 of each 21-day cycle. Patients received
up to six cycles of treatment, and were not treated until significant
toxicities were under control (less than or equal to grade 1). The primary
objective was effect on survival, and secondary objectives were determining
the efficacy and safety of the treatments.
About OPAXIO(TM)
OPAXIO(TM) (paclitaxel poliglumex, CT-2103), which was previously
branded as XYOTAX(TM), is an investigational, biologically enhanced,
chemotherapeutic that links paclitaxel, the active ingredient in Taxol(R),
to a biodegradable polyglutamate polymer, which results in a new chemical
entity. When bound to the polymer, paclitaxel is rendered inactive,
potentially sparing normal tissue's exposure to high levels of the active
drug and its associated toxicities. Blood vessels in tumor tissue, unlike
blood vessels in normal tissue, are porous to molecules like polyglutamate.
Based on preclinical studies, it appears that OPAXIO is preferentially
distributed to tumors due to their leaky blood vessels and trapped in the
tumor bed allowing significantly more of the dose of chemotherapy to
localize in the tumor than with standard paclitaxel. Once inside the tumor
cell, enzymes metabolize the protein polymer, releasing the paclitaxel
chemotherapy. Preclinical and clinical studies support that OPAXIO
metabolism by lung cancer cells may be influenced by estrogen, which could
lead to enhanced release of paclitaxel and efficacy in women with lung
cancer compared to standard therapies. This is being studied in an ongoing
phase III trial.
About Cell Therapeutics, Inc.
Headquartered in Seattle, CTI is a biopharmaceutical company committed
to developing an integrated portfolio of oncology products aimed at making
cancer more treatable. For additional information, please visit
celltherapeutics.
This press release includes forward-looking statements that involve a
number of risks and uncertainties, the outcome of which could materially
and/or adversely affect actual future results. Specifically, the risks and
uncertainties that could affect the development of OPAXIO include risks
associated with preclinical and clinical developments in the
biopharmaceutical industry in general and with OPAXIO in particular
including, without limitation, risks that the OPAXIO MAA may not result in
a marketing approval in Europe, determinations by regulatory, patent and
administrative governmental authorities, competitive factors, technological
developments, costs of developing, producing and selling OPAXIO in the
various countries in Europe if OPAXIO is approved for marketing in Europe,
and the risk factors listed or described from time to time in the Company's
filings with the Securities and Exchange Commission including, without
limitation, the Company's most recent filings on Forms 10-K, 8-K, and 10-Q.
Except as may be required by law, CTI does not intend to update or alter
its forward-looking statements whether as a result of new information,
future events, or otherwise.
Cell Therapeutics, Inc.