Merck & Co., Inc. to Acquire Abmaxis, Inc.; Acquisition Further Enhances Merck Commitment and Capabilities in Biologics Research and Development

Under the terms of the acquisition agreement, Merck will acquire100 percent of the equity of Abmaxis for $80 million in cash, makingAbmaxis a wholly-owned subsidiary of Merck & Co., Inc. The agreementis expected to close in the second quarter of 2006. Seven HillsPartners LLC served as exclusive financial advisor to Abmaxis in thistransaction.

Merck also announced today its acquisition of GlycoFi, Inc., aprivately-held biotechnology company that is a leader in the field ofyeast glycoengineering and optimization of biologic drug molecules.That acquisition is the subject of a separate news release.

"Our acquisition of Abmaxis provides Merck with the opportunity tooptimize and humanize antibodies, as well as to discover newantibodies," said Peter S. Kim, Ph.D., president, Merck ResearchLaboratories. "This, coupled with Merck's own industry-leadingcapabilities in yeast expression technology and our acquisition ofGlycoFi and its complementary technologies, positions us to become asignificant player in the important and growing field of biologicdrugs."

Founded in 2000 and located in Santa Clara, CA, Abmaxis gained theattention of the biomedical research field for its breakthroughantibody engineering technology platform, Abmaxis in-silicoImmunization (AISIM TM), which enables structure-centric computationaldesign followed by experimental selection of optimized human orhumanized monoclonal antibodies. The starting point for the processcan be an antigen target, a murine, animal or human antibody.

Under a collaboration agreement Merck established with Abmaxis inlate 2004, Abmaxis successfully re-engineered a Merck human monoclonalantibody and improved antibody affinity more than 70-fold whileretaining its specificity.

"The overwhelming success of that collaboration was a key factorin Merck's decision to pursue an acquisition with Abmaxis," said MervTurner, Ph.D., Merck's senior vice president, Worldwide Licensing andExternal Research. That and a visit in March to Abmaxis' headquartersby a Merck team headed by Dr. Kim led to the decision that "this isthe kind of superb science we want to bring into Merck."

Dr. Turner added that the Abmaxis technology would also help makeMerck a partner of choice for biotechnology companies seeking todevelop antibodies against their internal targets.

"Ours has been an excellent collaboration of scientific talent,and we are delighted at this most recent turn in Abmaxis' relationshipwith Merck," said Shirley Clayton, chief executive officer of Abmaxis."We are confident that Merck can maximize the value of our noveltechnology platform to expand its presence in the biologics field."

Her words were echoed by Dr. Peter Luo, Abmaxis co-founder andchief technology officer, who said, "We are excited by Merck's newgame plan and its commitment to build world-class research anddevelopment capabilities in biologics. We are looking forward toworking with Merck colleagues to achieve that goal."

Richard N. Kender, vice president of Business Development andCorporate Licensing at Merck, noted, "This acquisition is anotherexample of delivering on Merck's strategic objective of acquiringbiotechnology companies that complement our pipeline and ourconsiderable internal research capabilities."

About Merck

Merck & Co., Inc. is a global research-driven pharmaceuticalcompany dedicated to putting patients first. Established in 1891,Merck currently discovers, develops, manufactures and markets vaccinesand medicines to address unmet medical needs. The Company devotesextensive efforts to increase access to medicines through far-reachingprograms that not only donate Merck medicines but help deliver them tothe people who need them. Merck also publishes unbiased healthinformation as a not-for-profit service. For more information, visitwww.merck.com.

About Abmaxis

Abmaxis, Inc. is a privately held biopharmaceutical companylocated in Santa Clara, California. It is dedicated to the discovery,optimization and development of monoclonal antibody (MAb) products forhuman therapeutics and diagnostics. The company has a seasonedmanagement team with experience in the biotech, pharmaceutical andlife science industries. Abmaxis has developed and validated abreakthrough antibody engineering technology platform, Abmaxisin-silico Immunization (AISIMTM), which is used for building aninternal product pipeline and for collaborations with global biotechand pharmaceutical partners. The product strategy is to develop apipeline of products with a spectrum of risk profiles, ranging fromnext-generation of clinically proven antibody drugs with significantlyimproved attributes to antibodies against novel targets. Abmaxiscollaborates with corporate partners who have proprietary targets orantibodies that require humanization and engineering.

Merck Forward-Looking Statement

This press release contains "forward-looking statements" as thatterm is defined in the Private Securities Litigation Reform Act of1995. These statements are based on management's current expectationsand involve risks and uncertainties, which may cause results to differmaterially from those set forth in the statements. The forward-lookingstatements may include statements regarding product development,product potential or financial performance. No forward-lookingstatement can be guaranteed, and actual results may differ materiallyfrom those projected. Merck undertakes no obligation to publiclyupdate any forward-looking statement, whether as a result of newinformation, future events, or otherwise. Forward-looking statementsin this press release should be evaluated together with the manyuncertainties that affect Merck's business, particularly thosementioned in the cautionary statements in Item 1 of Merck's Form 10-Kfor the year ended Dec. 31, 2005, and in its periodic reports on Form10-Q and Form 8-K, which the Company incorporates by reference.