A volatile couple of months preceded last week's release of Motley Fool Rule Breakers pick PDL BioPharma's (NASDAQ:PDLI) third-quarter financial results. Since August, PDL's lead drug has failed in clinical testing, the breaking apart of the company has been announced, and its CEO has resigned.

At least on the revenue side, everything is all right at PDL. Royalty revenue was up 30% year over year. There's a bit of quarterly fluctuation with the royalty payments that PDL receives on marketed humanized monoclonal antibodies thanks to the annualized tiered royalty rate from Genentech (NYSE:DNA). Last quarter, for example, royalty revenue was up 48% year over year.

On an annualized basis though, PDL still looks set to easily meet my conservative forecast of 25% royalty revenue growth through 2013. Royalties from Elan's (NYSE:ELN) multiple sclerosis drug Tysabri are set to heat up next year and there's always the prospects for royalties on Alexion Pharmaceuticals' (NASDAQ:ALXN) Soliris in the future. Hitting this annualized royalty revenue growth rate matters, since it is by far the largest input into my $24 a share valuation for PDL's tangible assets.

Speaking of PDL's valuation, following the securities and exchange filing on Friday showing that hedge fund Third Point had sold all of its PDL holding, shares of PDL have fallen more than 4%.

By my modeling, this brings shares of PDL into the undeniably undervalued level again for value investors willing to take a bet that interim CEO Patrick Gage will see to it that PDL gets fair value for its biggest assets.

When I last wrote about PDL in early October, shares were trading near $24, much closer to my $27-$31 fair value range, and I didn't like the risk-reward proposition at that level. Shares of PDL no longer present the opportunity for multibagger returns that biotech investors are always searching for, but with so many tangible assets, at less than $19 a share, PDL again looks like the rare biotech value play.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has an awesome disclosure policy.