The targeted therapy approach to gastrointestinal diseases like ulcerative colitis and inflammatory bowel disorder are largely dominated by the blockbuster monoclonal antibody drugs like Humira and Remicade.
Bay Area startup Protagonist Therapeutics just raised a $40 million Series C to advance its oral, peptide-based gastrointestinal drugs – taking a precision medicine approach to ultimately go up against the top-selling “mabs.”
CEO Dinesh Patel told MedCity News that Protagonist plans to advance its lead candidate, PTG-100, into human trials by the end of the year for ulcerative colitis and inflammatory bowel disease. It plans to use pharmacogenomics from the beginning.
GI disease is the low-hanging fruit at present, but Protagonist is envisioning broader applications for its peptide-based oral drugs, Patel said.
PTG-100 works by specifically blocking alpha-4-beta-7 integrin, which already is a clinically validated target for IBD, Patel said. Protagonist plans to advance PTG-100 into Phase 1/2 trials for IBD patients in 2016.
Oral peptide drugs create a high degree of differentiation from injectable antibodies, Patel said. Further, its drugs are orally stable peptides that are restricted to the GI compartment – meaning they’ll have very little exposure in the stomach.
“With these features, we believe we’ll be able to create safer, more effective, more convenient drugs that people can take for chronic illnesses like IBD,” Patel said.
A Deep-dive Into Specialty Pharma
A specialty drug is a class of prescription medications used to treat complex, chronic or rare medical conditions. Although this classification was originally intended to define the treatment of rare, also termed “orphan” diseases, affecting fewer than 200,000 people in the US, more recently, specialty drugs have emerged as the cornerstone of treatment for chronic and complex diseases such as cancer, autoimmune conditions, diabetes, hepatitis C, and HIV/AIDS.
Humira and Remicade each exceeded $10 billion in sales last year – with an impressive chunk of that relegated to Crohn’s and ulcerative colitis treatment. But with these injectable monoclonals, about one-third of patients are non-responders from the get-go, Patel said – and another third get into relapse mode within a year of therapy. Basically – there’s a large population of UC and Crohn’s patients for whom the current blockbusters just aren’t very effective.
Further, the current physician approach to GI therapy is to start out simple – using inexpensive anti-inflammatory generics like corticosteroids and immune system suppressors like cyclosporine to first treat GI patients. Humira and Remicade are used as more last-choice approaches, Patel said – but a school of thought is now favoring earlier use of targeted therapy.
Sequencing patients for their reaction to GI drugs will likely be a more widespread approach in the near future, Patel said – a flip on the current treatment paradigm. An effective, targeted oral therapy could help that transition go more smoothly, he said.
The new funding round was led by new investor Canaan Partners, along with Adage Capital Management, RA Capital Management and Foresite Capital. All the company’s other investors – Johnson & Johnson Innovation, Lilly Ventures, Pharmstandard International and Starfish Ventures – joined the new round as well.
To date, Protagonist has raised $67 million in total – a $9 million Series A, $18 million Series B and the newest $40 million. It’s a spinout from the University of Queensland’s Institute of Molecular Biosciences.
