Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Biotech / Medical : Pharmacyclics (PCYC) -- Ignore unavailable to you. Want to Upgrade?

To: mopgcw who wrote (687)	10/9/2002 11:05:31 AM
From: keokalani'nui	Respond to of 717

Am I wrong, hasn't gadolinium been used as an imaging agent for ages? Pharmacyclics Announces Interim Results From Xcytrin Phase 2 Clinical Trial In Primary Brain Tumors Studies Also Highlight Use of Xcytrin to Better Define Target Radiation Area Wednesday October 9, 8:01 am ET NEW ORLEANS, Oct. 9 /PRNewswire-FirstCall/ -- Pharmacyclics, Inc. (Nasdaq: PCYC - News) today announced that researchers presented interim results from its Phase 2 clinical trial of Xcytrin® (motexafin gadolinium) Injection for the potential treatment of glioblastoma multiforme (GBM, or primary brain tumors) at the 44th Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO). A potentially groundbreaking analysis from this study, presented in a separate report here, describes the use of Xcytrin in functional imaging to better define tumor boundaries for more accurate targeting of radiation therapy to the tumor site. Researchers led by Dr. R.R. Manon of the University of Wisconsin's Department of Human Oncology reported that Xcytrin, which selectively localizes in tumor cells and can be visualized by magnetic resonance imaging (MRI), has the potential to provide radiation oncologists with improved ability to better define the target area of therapy and more accurately pinpoint the radiation beam to encompass the entire tumor. This could enable more effective radiation therapy with less risk of damage to adjacent normal tissue. "These early data from the Phase 2 trial and results from a previously reported Phase 1 trial indicate that Xcytrin may have the potential to improve survival in these patients, who have few if any viable treatment options," said John M. Suh, M.D., radiation oncologist at the Cleveland Clinic Foundation and one of the principal investigators. "We are also very excited about our results indicating that Xcytrin's selective uptake in tumors and MRI detectability may enable us to more accurately aim the radiation beam to optimize radiation therapy in a way we have never been able to before." Study Details and Results Twenty-five newly-diagnosed GBM patients were enrolled at eight leading medical centers in this single-arm study designed to evaluate the safety, pharmacokinetics and effect on survival of a six-week treatment course of Xcytrin combined with a standard six-week course of radiation therapy. Xcytrin was given daily for the first 10 days of radiation, then three times per week for the next four weeks, for a total of 22 doses of Xcytrin. The preliminary data show that over 80% of patients were alive at 6 months. The median survival in this study is 12.6 months to date; 9 of the 25 patients are still alive and being followed. This compares favorably to median survival reported in the literature of about 10 months for these types of patients. Xcytrin was well tolerated with the most commonly observed side effects being reversible skin and urine discoloration, rash and transient paresthesias (i.e., tingling in the extremities). Xcytrin did not interfere with the ability to deliver standard radiation, and the majority of patients were able to receive all of the intended doses of drug. Xcytrin for Functional Imaging and Treatment of Tumors In another portion of this Phase 2 study involving 15 patients, MRI scans were performed mid-way through the six-week course of radiation. Tumor size and location were determined based on the MRI signal enhancement produced by Xcytrin. As was the case in this study, radiation treatment planning for GBM is traditionally based on the use of a pre-radiation therapy MRI to identify the tumor and to define the initial radiation treatment volume and "boost" volume. The initial tumor volume, which includes detectable tumor and a margin determined by standard MRI scans, receives four weeks of radiation. An additional two weeks of therapy, or a "boost," is given to a smaller volume encompassing just the detectable tumor. MRI scans obtained after patients received Xcytrin were used to evaluate tumor size and location and compared to the standard pre-treatment scans. The objective of the study was to determine the likelihood that part of the tumor could be missed by the radiation therapy beam and to determine if Xcytrin-enhanced MRIs could help better define tumor volumes than standard MRI. Surprisingly, Xcytrin-enhanced MRI scans demonstrated that 12 of 15 patients (80%) had either a partial (53%) or complete (27%) geographic miss. In only 3 of 15 patients (20%), were the initial and boost radiation fields clinically acceptable, defined as encompassing the entire tumor and margins. A partial miss meant that the radiation field was too close to the edge of the tumor (<1cm). A complete miss meant that the tumor edge was beyond the boundary of the radiation. In both of these situations, inadequate radiation is delivered to the tumor. "We are very excited about these results, which could alter the way radiation therapy is administered," said Markus Renschler, M.D., vice president of oncology clinical development at Pharmacyclics. "We are already investigating how Xcytrin can play an integral role in functional imaging of other cancers to improve the radiation oncologist's ability to target the radiation beam more precisely, in order to encompass all the tumor and minimize damage to normal tissue. We want to take advantage of Xcytrin's dual properties to better define the margins of the tumor, potentially allowing improved radiation beam targeting, as well as potentially enhancing the efficacy of the radiation."