Yesterday, development-stage biopharma Human Genome Sciences (NASDAQ:HGSI) announced its second-quarter financial results following a quarter full of developments with its two lead drugs.

In June, Human Genome released phase 2 data on potential hepatitis C treatment Albuferon and lupus-fighting compound Lymphostat. Albuferon is being tested as a potential first-in-class longer-acting form of interferon alpha that will compete with existing interferon therapies from Schering-Plough (NYSE:SGP) and Roche.

In the phase 2 data, Albuferon produced mixed results when compared to Roche's Pegasys. Efficacy in the intent-to-treat Albuferon arms was comparable to Pegasys, but there wasn't any apparent dose-dependent response in patients taking the higher bimonthly dose of Albuferon.

By far the worst issue to crop up in the study is that patient dropout because of adverse events was significantly higher in all three of the Albuferon arms compared to Pegasys. Even at the lowest 900-mcg dose of Albuferon, discontinuation in patients taking the drug was 9.3%, compared to only 6.1% for Pegasys-treated patients.

This increased rate of patient drops thanks to adverse events is not going to be looked upon favorably by regulatory agencies if it continues in the phase 3 study, considering that the efficacy of Albuferon doesn't appear stronger than existing treatments and its other benefits, the easier dosing schedule and potential quality-of-life improvements, likely won't be enough to make up for this big issue.

The good news is that a subgroup of heavier patients appears to benefit more from Albuferon than existing patients. How well this translates into improved efficacy and safety in the ongoing phase 3 studies is not known.

Speaking of which, all four of the phase 3 studies for Albuferon and Lymphostat are currently under way. The two Albuferon trials are expected to complete enrollment in 2007, with data arriving in 2009. Development partner Novartis (NYSE:NVS) is also planning a new phase 2b study to evaluate treating patients with higher doses of Albuferon.

Human Genome ended the second quarter with $700 million in cash and investments. On the conference call, management said that this would be sufficient for it to continue operations without the need for another cash infusion until at least the announcement of phase 3 data for Albuferon and Lymphostat. Hopefully for Human Genome investors, an infusion of positive clinical trial data will also be coming up.

Looking for more Foolish drug-stock coverage? Check out the Fool's market-beating Rule Breakers newsletter. You can check out all our recommendations, as well as get access to our message boards and exclusive content, with a 30-day free trial.

Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has a disclosure policy.