Using bioengineered yeast which is cheaper than mammal cell methods, biotech firm GlycoFi has been able to make drugs more effective in fighting diseases like cancer by manipulating the sugars attached to the drugs.

With this new method, the scientists were able to demonstrate an improved function of Genentech’s Rituxan, the best-selling cancer drug in the United States. The studies were conducted by the 14-person firm based in Lebanon, New Hampshire as well as by researchers from nearby DartmouthCollege.

The results were published in the online edition of Nature Biotechnology on Sunday.

"By controlling the sugar structures on antibodies, we have shown that the antibodies’ ability to kill cancer cells can be significantly improved and that proteins can be optimized by controlling their sugar structures," said Huijuan Li, GlycoFi’s associate director of analytical development.

More than 140 therapeutic proteins have been approved in the United States and Europe, and there are around 500 more in clinical trials. The market is expected at a rate faster than 20 percent per year over the next ten years.

While some proteins used in human medicine have no carbohydrates attached to them, such as insulin, about 70 percent do. These sugar structures can affect how well a drug works and how long it works for.

The problem is that current manufacturing methods cannot reliably add the same types of sugars to the proteins in the same arrangements as they are found in the human body.

In the research paper, GlycoFi describes how it improved the function of Rituxan. The company purchased the non-Hodgkin’s lymphoma drug, and used its yeast to recreate the protein, adding each associated sugar one at a time.

“We found that some of the subspecies that are present in single digit percent quantities [in Rituxan] are 100 times more efficacious at killing cancer cells,” GlycoFi chief scientific officer and Dartmouth professor Tillman Gerngross told RedHerring.com.

GlycoFi has $35 million in financing from three rounds of venture funding and deals to help improve therapeutic proteins made by Merck, Eli Lilly, and MedImmune.