The Biotech Mailbag is open for business. An email from Ruth G. about melanoma drugs kicks us off. "Check out CRO-011 from Curagen ( CRGN). I work in a medical lab (not Curagen's) and I think it's the best of the lot," she writes. CRO-011 is an "armed antibody," which uses a monoclonal antibody to specifically target and kill cancer cells using a potent chemotherapy payload. Companies like ImmunoGen ( IMGN) and Seattle Genetics ( SGEN) are developing their own versions of armed antibody cancer drugs. In fact, Curagen's CRO-011 relies on the linker technology from Seattle Genetics to connect the antibody to the chemo payload. CRO-11 is in the midst of a phase II study in heavily pre-treated melanoma patients, with results expected later this quarter. Initial data from a dose-ranging portion of this study were presented at the American Society of Clinical Oncology annual meeting last June. Those data didn't exactly set the ASCO meeting on fire. Of the 13 patients treated with a 1.34 mg/kg dose of CRO-011, there was one patient with a partial response and six with stable disease. Six patients were evaluable at the 1.88 mg/kg dose used in the ongoing phase II study, with one unconfirmed partial response and three stable disease. To be fair, these are tough patients to treat because they have advanced disease, so any activity is encouraging. But then, melanoma is one of the most difficult, if not the most difficult, cancer types for which to develop new drugs. The list of melanoma drug failures is long and grows every year. At around 80 cents a share and a micro-market cap of $43 million, Curagen is a pure speculative play on CRO-011. To hammer home that point, consider that Curagen has a negative enterprise value of $15 million, which means investors essentially value the company's technology at zero. Results from the phase II study, due before year end, should shed more light on CRO-011's prospects.