Table 2.

Key points

• Even fully human monoclonal antibodies are potentially immunogenic

• Antibodies formed in response to treatment are mostly neutralizing

• In many (but not all) cases, pre-existing antibodies have little consequences

• Pre-existing antibodies should be carefully distinguished from false-positive results

• Pre-existing antibodies should be evaluated on a case-by-case basis using assays that yield information on the specificity of the antibodies