FibroGen, Inc. (NASDAQ:FGEN) shares are trading higher Tuesday after the company posted mixed first-quarter financial results. Here's a look at the key figures from the report.  The Details: FibroGen reported quarterly losses of 33 cents per share which missed the analyst consensus estimate of losses of 31 cents and represents a 59.26% increase year-over-year.  Quarterly sales clocked in at $55.902 million which beat the analyst consensus estimate of $36.666 million by 52.46% and is a significant increase over sales of $36.161 million from the same period last year. The company reported first-quarter net revenue growth of 55% year over year, driven by strong roxadustat performance in China and one-time drug product revenue recognized from the US/RoW AstraZeneca agreement termination.  Cash, cash equivalents, investments, and ...