Medical experts say new vaccines engineered with a tool called peptide binding are the next frontier for drugs that have long struggled to hit their targets.
New “cytokine receptor” vaccines promise to make standard medicines like Roche’s flu vaccine more potent or easier to deliver by a needle or via the tongue.
Like antibodies, peptides target invaders to repel them, in this case an immune system’s cells that attack cells as a foreign body. They can also be helpful for vaccines against HIV, several forms of cancer and even autoimmune disease. They’re small, for starters, so peptide vaccines can stay in the bloodstream longer than injections to reach cancer cells. And unlike conventional drugs, they’re not just molecular motors, yet their works are governed by bodies other than molecules.
Any new drug that alters biological processes by the small amount of protein or element in its chemical scaffolding would need a proving ground first, said Dr. George Church, an immunologist and professor at Harvard Medical School.
You get more work, he said, if you are able to transform or amplify existing peptide sequences, or tweak the ones you already have.
“The great hope is to see if we can extend it into a new therapeutic tool to get over the cancer gap,” said Dr. Robert M. Parkinson, director of New York University’s Center for Human Embryonic Stem Cell Research.
There’s a challenge, though: nearly 100 medicinal peptides, or “peptides,” have been studied for safety or efficacy, but fewer than 100 have successfully demonstrated any kind of anti-tumor effect, said Mark Haines, vice president of the Institute for Systems Biology.
A batch of three peptides, for instance, were tested for their ability to shrink tumors and manage autoimmune conditions like Crohn’s disease or multiple sclerosis. All hit their marks, but what Haines called “A-I” peptides proved useless. Pherogenic peptides have already been studied in numerous diseases, some after decades of searching for synthetic solutions.
“They’re very good as adjuvants,” Haines said, referring to what researchers call “reservoir enhancers.” Those are certain molecules in the same chemical structure that can bring a treatment to market. The peptides being developed today should be more effective at conjugating to other substances to kick-start their process.
Dr. Sarah Watanabe, a physiologist at the University of Washington’s Institute for Protein Design, confirmed that the ideas are already out there — and that they show promise. She sees a push toward peptide-based technologies.
Several companies are rolling out peptide injectable technologies. Including Tranzyme, a small, L.A.-based firm. It is developing medical delivery devices that deliver peptides to the patient. The company’s product — a nasal-sized needle to inject so-called anti-tumor peptides — is in human clinical trials.
Based on clinical results so far, they plan to go public in the first half of next year, said Tranzyme’s founder and chief executive, Steve Tregay.
“This is a big space, and we think there are a lot of companies that are going to build big and healthy businesses,” Tregay said.
The new approaches could also make doctors safer than before.
Mimicking the peptide structures of others’ peptides with the approach of papidryn, a technology created by BioArx, and targeting the peptide’s qualities, would limit how the drug might react with the body’s hormone system.
So could the new technology hurt the development of new medicines, though it may offer us a different way to ingest new drugs.