written by Michael O’Leary
Two companies announced clinical trials in the last three weeks aimed at bringing insulin taken by mouth to market.
Generex Biotechnology Corporation announced at the end of January results of a phase III clinical trial showing that its oral insulin spray Oral-lyn™ is as effective as subcutaneously injected regular insulin. The 12-week study conducted by an Indian licensee of Generex involved 209 men and women with type 2 diabetes at 14 clinics in India who did not have well controlled blood sugar levels with oral diabetic drugs.
While the Indian company that conducted the trial released few details of the study results, it advised the drug’s maker, Generex, that it had submitted the study results to Indian drug approval agencies and expected it to be approved this summer. The drug comes in an inhaler, much like asthma drugs, and is delivered in a metered spray through the mouth.
Last week Israeli company Oramed Pharmaceuticals reported that it is ready to launch a phase II clinical trial that it hopes will take it one step closer to putting its oral capsule on the market for people with type 2 diabetes. The study will be conducted at 12 clinical sites in the U.S. and will enroll close to 150 people.
Scientists have been searching for a way to administer oral insulin for more than 100 years. The difficulty is that stomach acid breaks down the insulin making it unusable by the body, and the intestines block absorption of large molecules such as insulin. Inhaled insulin has been tried, but early versions met with an increased risk of lung cancer.
Generex and Oramed have overcome these limitations by changing the delivery route of the insulin.
Oramed’s capsule overcomes the dual obstacles of stomach acid and molecule size with a special capsule coating that protects the insulin through the esophagus and stomach, and into the intestines. There the capsule breaks down and releases the insulin along with an absorption enhancer that transports the insulin protein across the intestinal membrane. Once across the membrane, the insulin travels through the blood directly to the liver where it is used like natural insulin.
In Generex’s case while it is sprayed into the mouth, it is not inhaled. Instead it is absorbed into the blood stream through the mucous membrane in the mouth.
A number of other companies with a variety of delivery strategies are all racing to get oral insulin tested and approved. Until recently most experts doubted an oral insulin could be achieved. Now, as Oramed CEO Nadav Kidron, said in an interview with Israeli magazine 21c, it is no longer a question of if, but when.
“When they initiated this project almost 30 years ago at Hadassah (University in Israel), trying to get insulin delivered orally looked almost impossible,” says Kidron. “Today it’s just a matter of time till it’s on the market.”