Washington: Patients suffering from cancer may soon face better therapy options as a team of researchers has introduced a new method of drug delivery that has produced strong results in the treatment of cancers in animal models, including some difficult to treat Solid and liquid tumors.
The new method involves a class of drugs known as antibody-drug (ADC) conjugates, which include some of the most promising next-generation therapeutic antibodies for cancer. ADCs can provide a cytotoxic payload in a manner that is markedly selective for the tumor. So far, three ADCs have been approved by the Food and Drug Administration of the United States (FDA), but do not bind the drug to a site defined in the antibody.
“We’ve been working on this technology for some time,” said author Christoph Rader. “It is based on the selenocysteine of seldom-used natural amino acids, which we insert into our antibodies, which we refer to as selenomabs.” Antibodies are large immune system proteins that recognize unique molecular markers in tumor cells called antigens. On his own, Rader noted that antibodies are often not powerful enough to eradicate cancer. However, their high specificity for antigens makes them ideal vehicles for drug delivery directly to tumor cells.
“We now show for the first time that selenomab-drug conjugates, which are ADCs that use the unique reactivity of selenocysteine for drug binding, are very precise, stable and potent compositions and promise wide utility for cancer therapy” , Continued.
Along with its power, Rader said, the ADC’s stability is fundamental to its effectiveness. The researchers found that their new ADCs showed excellent stability in human blood in vitro and in circulating blood in animal models. In addition, novel ADCs were highly effective against HER2 breast cancer, a particularly difficult cancer to treat, and against multiple myeloma CD138. Importantly, ADCs did not harm healthy cells and tissues.
“The selenomab-conjugated drug significantly inhibited the growth of aggressive breast cancer,” said first author Xiuling Li. “Four of the five mice tested were tumor free at the end of the experiment, six complete weeks after their last treatment.” The study appears in the journal Cell Chemical Biology.
