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 : Ligand (LGND) Breakout! -- Ignore unavailable to you. Want to Upgrade?

To: WTDEC who wrote (28940)	6/24/1999 12:03:00 AM
From: Night Trader	Respond to of 32384

The 95% confidence interval for the proportion of the population that will receive partial or complete response ranges from .37 to .58. i.e. based on this small sample we can be 95% certain that this proportion is between these two numbers. Put another way there is only a .025 chance that the proportion of the afflicted receiving benefit is less than 37%. A larger sample with the same results would have a much tighter range (I guess they got what they needed with only 84 people so this was unnecessary).

To: WTDEC who wrote (28940)	6/24/1999 2:59:00 AM
From: Henry Niman	Read Replies (1) \| Respond to of 32384

Walter, As noted, the CI is the confidence interval. This range gets tighter as the population size gets larger. However, since the protocol required a number of 20% or more, LGND easily beat that number, even when the low end of the range is used (37% vs the required 20%). Thus, even with a small number of patients, LGND was able to easily demonstrate efficacy as measured by patient response to the treatment. Assuming that the results on the 84 patients were representative, larger numbers of patients would have brought the lower end of the range closer to the 48%. Thus, if 150 patients were tested, the numbers might have been 48% with a confidence interval of 43% to 53% and if 500 patients were in the trial, the limits might have squeezed down to 46% to 50%. I don't see the response rate as being a problem (even with small numbers, the lower end of the confidence limit is well above the required 20%). The shortfall is in the remission rate. The protocol set a 5% remission rate for the lower end of the 95% confidence limit. This number was not achieved at the 300 mg dosing level. It was achieved at the 600 mg level, but more side effects were associated with that high dose, so LGND is applying for approval for the 300 mg dose. Thus, LGND was unable to demonstrate a significantly high complete remission rate, in part because the population size was small (the entire population, which was small, was treated at three different dose levels). CTCL is a relatively rare condition, so I suspect that the low numbers were due in part to accrual rates and associated costs with dragging out the trial longer. At this stage it is clear that a significant number of patients responded to the treatment, but it is unclear as to whether the complete remission rate is better than the 5% that might have been expected from a placebo (the protocol did not include a placebo arm, which I suspect was due to the difficulty in accruing patients).

To: WTDEC who wrote (28940)	6/24/1999 8:53:00 AM
From: Henry Niman	Respond to of 32384

As noted last night, the Targretin NDA was favorably covered by DJ. This morning LGND's filing made the Stocks to Watch segment. LGND's bid is up to 11 1/16 as the market responds favorably to the good news. A synopsis of the Stocks to Watch segment is linked to the CNBC Specials table at pharmacognizance.com