Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of XOMA (NASDAQ:XOMA), a biopharmaceutical company focused on developing antibody-based therapeutics, dipped as much as 19% on the day after reporting its first-quarter earnings results after the closing bell last night.

So what: For the quarter, XOMA produced revenue of $3.4 million, down 64% from the year-ago period when it delivered $9.5 million in revenue. XOMA blamed the drop on reduced reimbursements from Servier associated with gevokizumab's development activities. As noted in its press release, Servier met its end of the bargain by paying for the initial $50 million in gevokizumab development costs. Now, XOMA shares those costs with Servier 50-50. Net loss for the quarter, excluding warrant value changes, grew to $24.7 million, or $0.23 per share, from $12 million, or $0.15 per share, in the year-prior period. Comparatively, Wall Street was expecting a narrower loss of just $0.17 per share.

Shares were also under pressure after a price-target downgrade from Ladenburg Thalmann to $8 from $10 after the company announced that slow patient enrollment may delay the completion of its EYEGUARD-C trial beyond the end of this year. XOMA had initially planned to complete the trial by year's end.

Now what: The disappointments just keep racking up for XOMA with a wider-than-expected loss, and a potential delay in its EYEGUARD-C trial. Keep in mind that this follows the March swoon after it discontinued its mid-stage study of gevokizumab as a treatment for erosive osteoarthritis of the hand, or EOA. There's definitely a lot of potential indications for gevokizumab, and one therapy can often have a marked different effect from one disease indication to another, so there's still a lot of hope even after its failure in EOA. However, as an investor, I'd suggest sticking to the sidelines until we have something more concrete to go off of than just "hope."

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.