What's not to like about Human Genome Sciences (NASDAQ:HGSI)? This year, it might boast four late-stage drug candidates to potentially treat blockbuster indications, in partnership with some of the world's largest pharma companies.

Yesterday, Human Genome updated investors on the progress of its drug pipeline, including visions of brisk sales for anthrax treatment ABthrax. Like Gilead Sciences (NASDAQ:GILD), Baxter (NYSE:BAX), and GlaxoSmithKline (NYSE:GSK) with their bird flu treatments, Human Genome is producing a lucrative drug to fill a government-requested niche. The company expects sales of ABthrax to the U.S. government to total between $100 million and $120 million in 2008, with more to come in future years.

Investors also won't have to wait long for pivotal clinical trial data on Human Genome's other lead drug candidates. Hepatitis C treatment Albuferon is expected to produce the first of its phase 3 results in late 2008, with all of its phase 3 data rolling in by the spring of 2009. Lupus treatment LymphoStat-B should yield key phase 3 data by mid-2009 and the fall of the same year. If all goes well, Human Genome expects to complete marketing applications for both compounds by early 2010, with their first sales arriving that same year.

These two compounds won't be Human Genome's only phase 3 drug candidates this year, either. Partner GlaxoSmithKline will push its atherosclerosis compound into phase 3 testing in 2008. It'll also decide this year whether to advance Syncria, its GLP-1 diabetes drug -- like Amylin Pharmaceuticals' (NASDAQ:AMLN) Byetta -- into phase 3 testing.

Human Genome unarguably has a very deep pipeline for a drugmaker of its size. Given additional resources, it can reach into its basket of discovery-stage assets and pull more compounds into the clinic. Just like fellow biopharma Medarex (NASDAQ:MEDX), though, its lead compounds are extremely high-risk/high-reward propositions, even for a young biopharma. Based on its phase 2 data, I'm not sold on Albuferon's utility in particular.

If Human Genome can achieve multiple clinical-trial and regulatory successes with its compounds, the potential for its shares seems truly limitless, especially considering the depth and breadth of its pipeline. However, at an $800 million market capitalization, the risk-reward proposition on Human Genome still seems skewed in the wrong direction. The clinical, regulatory, and commercialization risks for both Albuferon and LymphoStat are too great for this analyst. Investors may do well to wait until at least some of these drugs' clinical trial results come out before jumping in.