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Biotech / Medical : Biotech Valuation -- Ignore unavailable to you. Want to Upgrade?

To: jeffbas who wrote (420)	10/4/1999 11:29:00 AM
From: biowa	Respond to of 52153

Jeffrey, What you write might be true if: 1) The data really was comparable. Trial populations, definition of disease, other supportive care and therapy (in trial), participating doctors, etc. ad nauseum differ even among concurrent ongoing trial. Most historical data isn't even collected with an eye towards being used in an FDA filing and wouldn't pass muster. And there's the infamous placebo effect (basically a syndrome being studied in a clinical trial probably is treated more aggressively - besides the therapy specifically under trial - so that even the patients in the control arm do better than historical). Therefore, accurate comparison requires, matched (hopefully) populations of patients being treated by the SAME doctors in the same way with the same criteria, etc.). 2) The standard of care didn't change with time. AMLN saw this even over the course of a trial, when tight blood glucose control became more of a passion, screwing up their data. So add to the criteria at the end of the last paragraph: over the same time period. biowa

To: jeffbas who wrote (420)	10/4/1999 11:54:00 AM
From: Biomaven	Respond to of 52153

Jeffrey, Here's a concrete example for you to consider in light of biowa's excellent response. It's a report of PCYC's Phase II results for Gd-Tex. It basically does what you suggest, albeit with fewer patients. However given the many failures by other biotechs in Phase III after promising Phase II results, I don't think many would be comfortable having the drug approved on the basis of this study alone. (On the other hand, speaking as an investor, I am quite comfortable investing based on this study, which I find quite convincing.). (I should add that assessing the quality of Phase II tests is one of the most significant aspects of good biotech investing. Small biotechs sometimes skimp on the Phase II's and end up in expensive Phase III's with the wrong indication or dosage. ) An intent-to-treat efficacy analysis was performed on all 61 patients entered into the phase Ib/II trial. Although this was not a randomized trial, efficacy results were compared to historical controls using a 528 patient data base containing information on prognostic features and outcomes in patients with brain metastases receiving treatment with identical doses of radiation alone. A case matching method was used to insure that patients in the Gd-Tex treated and the historical control groups were similar with respect to known prognostic features. After 6 months and 12 months, 41% and 25% of Gd-Tex treated patients were alive compared to 30% and 14% of the controls respectively. Gd-Tex treatment was a statistically significant independent prognostic factor in determining survival (p=0.034). The effect of Gd-Tex treatment on neurologic progression was determined by comparing the causes of death in the treated patients to those of the control patients. Death due to tumor progression in the brain was seen in 15% of Gd-Tex treated patients compared to more than 35% in the control group. Also reported at ASTRO, were the results of an independent analysis comparing the survival of the Gd-Tex treated patients to patients treated with radiation therapy for brain metastases by the Radiation Therapy Oncology Group (RTOG), a large cooperative clinical research group in the U.S. In a case-matched control analysis performed by RTOG, it was possible to identify case-matched controls for 37 Gd-Tex treated patients. Gd-Tex treated matched patients had significantly increased survival compared to controls (p=0.05). At 6 months and 12 months, 54% and 30% of Gd-Tex treated matched patients were alive compared to 32% and 11% in the case-matched controls respectively. In RTOG studies, 49% of patients died due to tumor progression in the brain, compared to 15% of Gd-Tex treated patients as noted above. "Gd-Tex treatment appears to reduce progression of tumor in the brain, which may provide important functional and quality of life benefits to patients with brain metastases," stated Markus Renschler, M.D., senior director of clinical research at Pharmacyclics and a co-author on the study. "In two independent case-matched control analyses, Gd-Tex also appears to have had a favorable impact on survival. We intend to confirm these results in our recently initiated phase III trial designed to evaluate the effect of Gd-Tex on neurologic progression and survival." Peter