The world’s largest drug maker may be buying one of its development partners in RTP.

Pfizer (NYSE: PFE) said in a regulatory filing Friday that it was considering a “stock or asset acquisition or meger” with Icagen (Nasdaq: ICGN).

In a statement issued late Friday, Icagen confirmed the talks.
The company “acknowledged that it is currently engaged in preliminary discussions with Pfizer regarding a potential strategic transaction.”

However, Icagen said no deal has been reached and added that there is “no assurance” one will be.

“No definitive agreement has been reached,” Icagen said. “There can be no assurance that any agreement will be reached or that a transaction will be consummated.”

The two firms have been partners since a potential $1 billion deal was announced in 2007.

The news sent Icagen shares soaring in after-hours trading on Friday. Shares more than doubled to $5 frfom $2.40, according to nasdaq.com.

Pfizer and Icagen have been working together on three drug development deals that could mean more than 41 billion to the RTP firm. Pfizer commited to buying $5 million in Icagen stock most recently in September 2010. It purchased $5 million in stock shortly after the partnership was announced in 2007.

In the SEC filing, Pfizer said:

“As part of Pfizer’s ongoing evaluation of the possible extension or other modification of the Collaboration Agreement, Pfizer is evaluating the possibility of entering into a strategic transaction with Icagen, which could have the effect of influencing or changing the control of Icagen by means of a stock or asset acquisition or merger (a “Strategic Transaction”). In connection with such evaluation, Icagen representatives and Pfizer employees have engaged in preliminary discussions regarding a potential Strategic Transaction and on June 14, 2011, Pfizer and Icagen entered into an amendment to the letter agreement dated October 10, 2006 in connection with disclosure of certain confidential information by Icagen (the “Confidentiality Agreement Amendment”).

“Pursuant to the Confidentiality Agreement Amendment, Icagen agreed to give Pfizer access to various due diligence materials. Based on and subject to the results of its due diligence evaluation, Pfizer may, if Icagen is willing, engage in further discussions with Icagen’s management and members of its board of directors that could ultimately lead to the drafting and negotiation of one or more transaction agreements and, if agreement can in fact be reached on terms mutually agreeable to the parties, the execution of definitive agreements that could effectuate either an extension or amendment of the Collaboration Agreement or a Strategic Transaction.

“No assurance can be made that Pfizer and Icagen will reach agreement on terms with respect to any such transaction prior to the expiration of the current Collaboration Agreement, if at all.”

(Read the full filing here.)

Under the initial deal with Pfizer, Icagen received an upfront fee of $12 million. Icagen said it included three product research deals worth as much as $359 million each plus royalties.

Icagen’s statement:

“In response to the filing of a Schedule 13D today by Pfizer Inc. in which Pfizer indicates, as part of Pfizer’s ongoing evaluation of the possible extension or other modification of the existing collaboration agreement between the parties, it is evaluating the possibility of entering into a strategic transaction with Icagen, which could have the effect of influencing or changing the control of Icagen by means of a stock or asset acquisition or merger, Icagen acknowledged that it is currently engaged in preliminary discussions with Pfizer regarding a potential strategic transaction. No definitive agreement has been reached. There can be no assurance that any agreement will be reached or that a transaction will be consummated. Icagen does not plan to make future announcements with respect to this matter unless and until its Board of Directors has approved a specific transaction or an extension or other modification of the existing collaboration agreement and it has entered into a definitive agreement or the current discussions have terminated.”

Get the latest news alerts: Follow WRAL Tech Wire at Twitter.