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Hybritech, Inc. v. Monoclonal Antibodies, Inc.

United States Court of Appeals for the Federal Circuit

September 19, 1986

Appeal No. 86-531


 [***81]  [*1368]   RICH, Circuit Judge.

This appeal is from the August 28, 1985, decision of the United States District Court for the Northern District of California, 623 F. Supp. 1344, 227 U.S.P.Q. (BNA) 215, in favor of defendant Monoclonal Antibodies, Inc. (Monoclonal) holding that all 29 claims of plaintiff's patent No. 4,376,110 entitled "Immunometric Assays Using Monoclonal Antibodies" ('110 patent), issued to Dr. Gary S. David and Howard E. Greene and assigned to Hybritech Incorporated (Hybritech), are invalid as anticipated under 35 USC § 102(g), for obviousness [***82]  under § 103, and under § 112 first [**2]  and second paragraphs. We reverse and remand.


Vertebrates defend themselves against invasion by microorganisms by producing antibodies, proteins which can complex with the invading microorganisms and target them for destruction or removal. In fact, any foreign molecule of sufficient size can act as a stimulus for antibody production. Such foreign molecules, or antigens, bear particular sites or epitopes that represent antibody recognition sites. B cell lymphocytes, the cells that actually produce antibodies, recognize and respond to an epitope on an antigen by reproducing or cloning themselves and then producing antibodies specific to that epitope. Even if the antigen is highly purified, the lymphocytes will produce antibodies specific to different epitopes on the antigen and so produce antibodies with different specificities. Furthermore, because the body is exposed to many different antigens, the blood of a vertebrate will contain antibodies to many different antigenic substances.

Scientists and clinicians have long employed the ability of antibodies to recognize and complex with antigens as a tool to  [*1369]  identify or label particular cells or molecules [**3]  and to separate them from a mixture. Their source of antibodies has been primarily the serum separated from the blood of a vertebrate immunized or exposed to the antigen. Serum, however, contains a mixture of antibodies directed to numerous antigens and to any number of epitopes on a particular antigen. Because such a mixture of antibodies arises from many different clones of lymphocytes, it is called "polyclonal."

Recent technological advances have made it possible to isolate and cultivate a single clone of lymphocytes to obtain a virtually unlimited supply of antibodies specific to one particular epitope. These antibodies, known as "monoclonal antibodies" because they arise from a single clone of lymphocytes, are produced by a relatively new technology known as the hybridoma. Hybridomas are produced by fusing a particular cancer cell, the myeloma cell, with spleen cells from a mouse that has been injected or immunized with the antigen. These fusions are isolated by transferring them to a growth fluid that kills off the unfused cancer cells, the unfused spleen cells dying off by themselves. The fused hybrid spleen and myeloma cells, called hybridomas, produce antibodies to the [**4]  antigen initially injected into the mouse. The growth fluid containing the hybridomas is then diluted and put into individual test tubes or wells so that there is only one hybridoma per tube or well. Each hybridoma then reproduces itself and these identical hybridomas each produce identical monoclonal antibodies having the same affinity and specificity. In this way, a virtually unlimited supply of identical antibodies is created, directed to only one epitope on an antigen rather than, as with polyclonal antibodies, to many different epitopes on many different antigens.

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802 F.2d 1367 *; 1986 U.S. App. LEXIS 20347 **; 231 U.S.P.Q. (BNA) 81 ***


Subsequent History: Writ of certiorari denied Monoclonal Antibodies, Inc. v. Hybritech, Inc., 480 U.S. 947, 107 S. Ct. 1606, 94 L. Ed. 2d 792, 1987 U.S. LEXIS 1437 (1987)

On remand at, Findings of fact/conclusions of law at Hybritech Inc. v. Monoclonal Antibodies, 1987 U.S. Dist. LEXIS 16937 (N.D. Cal., May 19, 1987)

Prior History:  [**1]   Appealed from: U.S. District Court for the Northern District of California. Judge Conti.

Hybritech v. Monoclonal Antibodies, 623 F. Supp. 1344, 1985 U.S. Dist. LEXIS 16405 (N.D. Cal., 1985)

Disposition:  Reversed and Remanded.


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