Preliminary PI-88 Phase 2 Prostate Cancer Results to be Presented at the American Society for Clinical Oncology (ASCO) 2008 Genitourinary Cancer Symposium
Wednesday February 13, 9:28 am ET
BRISBANE, Australia, Feb. 13 /PRNewswire-FirstCall/ -- Progen Pharmaceuticals Limited (ASX: PGL - News; Nasdaq: PGLA - News) today announced positive preliminary efficacy results from a phase 2 investigator-initiated trial of PI-88 in combination with the chemotherapeutic agent Taxotere® (docetaxel) administered to patients with prostate cancer. Dr. Gavin Marx, Royal North Shore Hospital, Sydney Haematology and Oncology Clinics, the principal investigator conducting the trial, will present the preliminary results of the study today at the American Society for Clinical Oncology (ASCO) 2008 Genitourinary Cancer Symposium in San Francisco.
The investigator-initiated study was a randomized two-arm open-label study design that assessed efficacy and safety of two dose schedules (4 days/week and 7 days/week) of subcutaneous PI-88 in combination with three-weekly Taxotere® (75 mg/m2, IV on day 1). The study comprised a lead-in phase 1 safety component to establish the maximum tolerated dose (MTD) of PI-88 at each of the two dosing schedules, followed by a randomized phase 2 component expanding the two dose schedule.
70% of the 55 patients recruited to the trial had a decrease in serum Prostate Specific Antigen (PSA) of greater than 50% for three weeks or longer. These efficacy results compare favourably with the pivotal TAX327 Taxotere® registration trial, where 45% of patients had at least a 50% decrease in serum PSA level(1). PSA is a substance produced in the prostate gland, a high level of which may indicate the presence of cancer. In patients with advanced prostate cancer, many clinicians use increasing levels of PSA as an indicator of disease progression.
The trial concluded enrollment early due to a higher-than-expected rate of febrile neutropaenia, a side effect involving a decrease in white blood cells with associated fever. This is a known side effect of Taxotere®, but was seen in this trial at a substantially greater rate than is generally considered typical for that drug.
Two patients are continuing with PI-88 treatment after successfully completing the combination treatment. Specifically, one patient has remained on the study after 74 weeks while the other remains after 40 weeks.
Dr. James Garner, Progen's Vice President of Clinical and Medical Affairs commented, "We are encouraged by the efficacy trends demonstrated in this patient population. Prostate cancer is an indication with continuing high unmet medical need and there is a clear demand for new therapies here. The febrile neutropaenia rates seen in this study are difficult to interpret, given that this small investigator-led study lacks a control group. We have not seen evidence of febrile neutropaenia in our previous clinical experience combining PI-88 with Taxotere®, and there is no biological reason to suspect that the combination might result in increased toxicity. We will discuss this unexpected finding with our clinical and scientific advisors to determine the appropriate next steps in terms of development."
Justus Homburg, Progen's Chief Executive Officer continued, "Prostate cancer continues to be an indication we are interested to explore more, therefore, we will continue to analyze the results and do additional work to establish how best to combine PI-88 with existing therapies in this indication. In the interim, our phase 3 study in the adjuvant hepatocellular carcinoma setting is expected to begin recruitment shortly. We do not anticipate any concern regarding febrile neutropaenia in this phase 3 study, as it is a monotherapy study in a patient population with which we already have substantial clinical data."
surf's up......crikey
