Symphogen is developing recombinant polyclonal antibodies (rpAb) for oncology targets. RpAb may be a next-generation treatment for cancer, because of their ability to provide an enhanced and more complete immune response than monoclonal antibodies against cancerous target antigens.

Monoclonal antibodies (mAbs) can be produced in unlimited quantities, which together with their specificity have expanded the therapeutic use of antibodies for cancer. Several hundred mAbs are in development and several have been approved for oncology treatment. However, a drawback of using mAbs against cancer is that elimination of a cancer cell depends on obtaining a sufficient number of antibodies on the surface of the antigen to induce the required effector mechanisms. Because mAbs inherently only target one area of the antigen, they may not be able to provide the antibody density needed to eradicate the cancerous cells. In order to improve efficacy, there is often a need for higher doses of the drug, which increases the risk of side-effects.

Another concern is the ability of cancer cells to mutate their genetic sequence, which necessitates a therapeutic that is able to address such mutations. A single mAb specific to only one section of an antigen may not be effective against mutations, because the mAb may no longer recognize the antigen’s changed structure. This may lead to drug resistance.

Symphogen believes that a recombinant pAb therapeutic may be more effective against complex targets, such as cancer cells. RpAb are active against a number of epitopes, so they may be superior to individual mAbs in targeting complex cancers. Researchers have found that mixtures of two antibodies produce enhanced neutralization compared to individual antibodies, demonstrating the feasibility of a polyclonal approach. A rpAb mixture may also reduce the likelihood of drug resistance, because cancer cells would need to acquire multiple mutations to escape all of the targeted antibodies.

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