Two big deals this week highlighted the industry's--and investors'--interests in new oral delivery platforms that introduce therapeutic proteins via the gut.
Startup Akebia Therapeutics raked in $41 million in Series C financing for its oral EPO therapy to treat anemia, and Protagonist Therapeutics took $14 million in Series B for its pipeline of oral peptide drugs focused on inflammatory diseases.
The main hurdle associated with oral peptide drugs is hitting the target. Because a protein's structure determines its function and because of the harsh environment of the gut during digestion, drugs don't usually make it through the digestive tract. The trick is to protect drugs through digestion to enter the bloodstream. Akebia and Protagonist each used a different method to overcome this obstacle.
Akebia, with its AKB-6548 currently in plans for a Phase IIb study later this year, employed hypoxia-inducible factor prolyl hydroxylase, or HIF-PH, to mimic lower-than-normal levels of oxygen in the blood, stimulating the body to create more of the oxygen-carrying protein EPO to treat anemia. Akebia focused on patients with kidney disease, but titanic competitors like GlaxoSmithKline ($GSK) and Astellas Pharma have their own oral anemia drugs in the race. Before this $41 million third round, Akebia pulled in a total of $47 million from the previous two.
Protagonist gained the interest of some large investors like Johnson & Johnson ($JNJ), Eli Lilly ($LLY) and Starfish Ventures, who saw promise in Protagonist's disulfide-rich peptides. These powered-up proteins have more oral stability and improved distribution, and the technology won Protagonist a 2011 endorsement from Ironwood Pharmaceuticals ($IRWD), known for the oral peptide Linzess for irritable bowel syndrome. Protagonist CEO Dinesh Patel told FierceBiotech that the company plans to use the recent $14 million, plus $9 million from a previous round of financing, to propel the inflammatory disease drugs into human studies by 2015-16.
- here's the Akebia release
- and here's the Protagonist release
- plus FierceBiotech's takes here and here