AN OVERVIEW OF BIOTECHNOLOGY


that both companies have become subsidiaries of major pharmaceutical
firms. In each case, the consideration involved was about $300 million.


THERAPEUTIC POTENTIAL

 Those engaged in monoclonal antibody research are looking to frontiers
beyond diagnostic aids. Recently this has resulted in the FDA approval of
Orthoclone OKT*3, produced by the Ortho Pharmaceutical Corporation.
The drug has proved useful in treatment of short-term episodes of kidney
transplant rejection. Research teams are also developing therapeutic anti-
bodies for intractable bacterial infections and are seeking agents for diag-
nosis and treatment of cancers.
 Some 60,000 patients in hospitals die each year as a result of opportunis-
tic infections by organisms that do not respond well to antibiotics. These
organisms, Klebsiella, Pseudomonas, and E. coli, produce potent endotox-
ins. These toxins can be neutralized by antibodies. However, mice cannot
be used to produce them. To avoid antigenic effects, the therapeutic anti-
bodies must be produced from human cell cultures. This is being done.
 Monoclonal antibodies have been heralded as potentially important in
the diagnosis and treatment of cancers. Tumor cells produce antigens on
their surfaces. These can be used to create corresponding antibodies.
When such antibodies are injected into animals or humans, they tend to
bind to the tumor cells. This may interfere with the cells' metabolism.
Clinical trials are in progress testing this approach. Another procedure is
to tag the antibody with a radioactive isotope of yttrium. This combina-
tion can be employed to detect metastases of a cancer. Hopes have also
been raised about using the radiation from the isotope as a treatment mo-
dality. Another approach that has been tried is to couple a toxin such as
ricin to the antibody in the hope that the toxin will destroy the tumor cell.
These hopes have been around for several years, but conspicuous success
has not been evident. Apparently, the agent which includes ricin and anti-
body is not sufficiently specific in its binding, and it affects normal cells as
well as tumors. A procedure is now being investigated by Cetus in which
only the toxic part of the ricin is attached to the antibody. This approach
may prove more effective and less toxic to normal cells.