I'd be happy to address any substantive argument for why FDA will approve Ampligen, the chronic fatigue syndrome drug from Hemispherx Biopharma ( HEB). So far, most of the responses to my column this week have been the "%^&* YOU, SHORT-SELLING SCUM!" variety. Funny but not very persuasive. Biotech trader @sheffstation believes the changing environment at FDA -- regulators more sympathetic to patients groups, taking a more proactive, friendly manner with regards to drug approvals -- works in Hemispherx's favor. Says Sheff: "A key point is that it took FDA only 13 days to accept the
@shakes2222 disagreed with my assertion that Navidea Biopharmaceuticals ( NAVB) is over-valued because actual Lymphoseek sales -- whenever the product is launched -- will fall far short of expectations. "So, every analyst has it wrong on NAVB? Does pipeline add value?" he asks. "If pipeline didn't matter, all start-ups would be worthless." In this case, I do believe that every sell-side analyst covering Navidea will be proven wrong. Their Lymphoseek sales estimates are way too high. I laid out my own sales projections in the column, so we now wait to see who's right. I like my chances. I didn't discuss Navidea's pipeline because it's thin and not worth much: RIGScan is a radio-labeled antibody designed to target and collect inside colon cancer cells. A surgeon uses a probe to detect the antibody-soaked cancer tissue and remove it. Interesting idea except Navidea has been trying to develop RIGScan for 16 years without success. The main problem is that U.S. and European regulators won't approve the agent unless Navidea runs a clinical trial proving that use of RIGScan during colon-cancer surgery improves patient outcomes. An outcomes-based trial in colon-cancer surgery would be very large, lengthy and expensive, so naturally, Navidea has tried to persuade regulators to drop the requirement. That strategy has failed. Assigning value to RIGScan at this point would be overly generous. AZD4694 is an experimental Alzheimer's imaging agent that binds to beta amyloid plaques and can be detected using a PET scan. Investors get excited when companies develop Alzheimer's-related products because the potential market is so large. A couple of problems with Navidea's development of AZD4794: 1. The company is well behind Eli Lilly ( LLY), which bought Avid Pharmaceuticals and its very similar Alzheimer's imaging agent Amyvid in 2010. Amyvid sales to date have been minimal. 2. Detecting amyloid may be a meaningless exercise because current research hasn't yet proven that using drugs to clear these protein plaques from the brain plays any role whatsoever in improving cognition or memory. So far, all the amyloid-clearing drugs studied -- like Lilly's solaneuzumab and Elan's ( ELN) bapineuzumab -- have failed spectacularly. Altropane is a radio-labeled imaging agent to aid in the diagnosis of Parkinson's disease. Navidea licensed the phase III-ready agent from a private company for $175,000 and 300,000 shares of Navidea common stock. Why do doctors need a radio-labeled agent to detect Parkinson's disease? Whatever small value you attach to Navidea's pipeline still can't justify the company's current valuation tied much more to Lymphoseek. --Written by Adam Feuerstein in Boston. >To contact the writer of this article, click here: Adam Feuerstein. >To follow the writer on Twitter, go to http://twitter.com/adamfeuerstein. >To submit a news tip, send an email to: firstname.lastname@example.org. Follow TheStreet on Twitter and become a fan on Facebook.