Your arithmetic is off; cash burn in 1Q13 was $14.9M (#msg-87718360). The company’s guidance for 2013 full-year cash burn is $50M.
Do you expect another raise before the first of the pivotals read out around the end of this year? I don't think it would be a big stretch given that if 2 of the 3 trials do fail (and not predicting that, who knows) XOMA is likely not going to be in great position to raise afterwards.