NEW YORK (TheStreet) -- Shares of Xoma Corp. (XOMA) are spiking by 18.26% to $1.05 in after-hours trading on Wednesday, after the Berkeley, CA-based company reported its 2015 fourth quarter results.

After today's market close, the antibody-based therapeutics company posted earnings of 21 cents per share, surpassing analysts' expectations for a loss of 15 cents per share.

Revenue for the period was $48.18 million, much higher than Wall Street's estimates of $4.01 million.

"The increase in the full-year and fourth quarter 2015 revenues was due primarily to our licensing activity in the fourth quarter, including a $37 million upfront payment from Novartis (NVS), a $5 million upfront payment from Novo Nordisk (NVO) and a $3.8 million payment from Pfizer (PFE)," the company said in a statement this afternoon.

About 1.81 million of the company's shares were traded today vs. its average volume of 1.35 million shares per day.

"The transformation we initiated in the third quarter of last year - and now have completed in less than six months - was considerable in its scale and complexity, but essential to position XOMA to deliver our promising portfolio of endocrine assets," CEO John Varian said in a statement.

Separately, TheStreet Ratings Team has a "Sell" rating with a score of E+ on the stock.

This is based on the combination of unfavorable investment measures, which should drive this stock to significantly underperform the majority of stocks rated.

The company's weaknesses can be seen in multiple areas, such as its weak operating cash flow and generally disappointing historical performance in the stock itself.

Recently, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.

You can view the full analysis from the report here: XOMA

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