Specifica Inc. 1512 Pacheco Street, Suite A203,

Santa Fe, NM 87505

505 471 0065


© 2019 by Specifica Inc. 

Exclusive Antibody Libraries

The dangers of fishing in the same pond: a tale of two patents

In 1998 Genentech filed a patent entitled "Apo-2 Receptor", that contained within it the sequences of antibodies recognizing the Apo-2 receptor. In 2004 Human Genome Sciences filed a patent entitled "Antibodies that immunospecifically bind to Trail Receptors" that included antibodies recognizing the Trail Receptor TR7. The sequence of one of the antibodies in the Genentech patent was identical to the sequence of one of the antibodies in the HGS patent. The sequences of the two targets described in the patents was essentially identical, differing by only a single C-terminal conserved amino acid. It appears that the identical antibodies were both selected from the same (or similar) 

natural phage antibody library produced and broadly licensed by Cambridge Antibody Technology. An interference was decided in Genentech's favor.

The chances of identical antibodies being selected against the same target in different laboratories from the same library at a distance of six years, using different methods would appear to be vanishingly small, given the diversities of these libraries. However, the fact that two companies attempted to patent the same antibody before the days of NGS indicates the potential danger. In examining this further, Specifica has found that when NGS is used to analyze selection outputs of antibodies selected against the same target in two different laboratories from the same natural library, up to 25% of the HCDR3s of selected antibodies are extremely similar, and that this drops to less than 0.2% when different libraries are used.

Whether this problem occurs with synthetic libraries has not yet been demonstrated, particularly as their underlying genetic diversity is potentially so high.


Specifica supplies unique libraries to each customer, in which NGS has been used to ensure minimal overlaps with previous libraries.