A race for a potentially lucrative contract to supply the federal government with drugs to treat anthrax is pitting local biotechs against each other. Rockville-based Human Genome Sciences got out of the gate early, landing a small contract worth $1.8 million to supply the feds with 10 grams of its anthrax drug for testing. If all goes well, the government could end up buying 100,000 doses, which could translate into $200 million for the company. The Department of Health and Human Services, as part of its $5.6 billion Project BioShield initiative, is expected to issue soon a request for proposals for a second anthrax drug contract. Federal officials won’t say when, but the companies are champing at the bit. Competing against Human Genome Sciences are Annapolis-based PharmAthene, Pine Brook, N.J.-based Elusys Therapeutics and Cangene, a Canadian company that also recently landed a small contract to supply HHS with its anthrax drug, a slightly different product from what the other three companies are attempting to develop.