Ra Pharma Gets $58.5M in Crossover Cash to Target Rare Blood Disease

Xconomy Boston — 

Ra Pharmaceuticals, a Cambridge,MA-based company that signed a large collaboration deal with Merck two years ago, has received a $58.5 million Series B financing to take its first drug, a potential treatment for an ultra-rare blood disorder, called paroxysmal nocturnal hemoglobinuria, into human clinical testing.

PNH occurs when a part of the immune system called the complement system misfires, unleashing an attack that destroys red blood cells and causes a host of severe health problems, like blood clots and organ failure. Ra’s proposed treatment is meant to fend off the wayward immune attack.

Ra’s treatment, known as RA101495, is only in preclinical testing so far—it’s got much to prove, and it’ll start down that path when its first trials begin later this year. But Ra’s goal is to someday have a drug that can compete with the likes of Alexion Pharmaceuticals (NASDAQ: ALXN), which received FDA approval in 2007 to treat PNH with its monoclonal antibody, eculizumab (Soliris), and now has a market capitalization approaching $50 billion.

Ra says RA101495 is a synthetic molecule that’s like a peptide, which is a string of amino acids similar to proteins, but smaller and typically more fragile. Ra’s molecule has a modified chemical structure that enhances its stability and potency, as Xconomy has previously reported.

Currently, RA101495 is injected just like most biologic drugs. Ra says its candidates have the potential to be taken orally because they still resemble a small molecule drug, however, which may help it compete with eculizumab down the line. Synthetic molecule should have a lower cost of goods than biologics, which will allow Ra flexibility in pricing and will increase patient access to therapies, Doug Treco, co-founder, president and CEO of Ra, wrote in an e-mail.

Ra is developing other drugs out of these peptide-like molecules, using a platform it calls Extreme Diversity. The platform’s potential lured Merck, which cut a $200 million collaboration deal with Ra in April 2013. That agreement has been extended, the companies say.

Other companies are developing peptide-based drugs that can be swallowed like pills instead of injected.

Protagonist Therapeutics received a $40 million funding round last week to help test the company’s oral peptide treatment for irritable bowel disease—and conditions that rise from it—in humans. Chiasma is a Newton, MA-based biopharma company trying to develop an oral octapeptide to treat orphan diseases typically treated with injectables. It raised $101.8 million in an initial public offering last week.

The Series B funding for Ra, meanwhile, will help pay for the development of RA101495 and some other drug candidates. The round includes a number of so-called “crossover” investors that typically back public companies, indicating Ra is at least positioning itself for an IPO down the road. The funding was led by RA Capital Management, Novo Ventures, and Lightstone Ventures. New investors Rock Springs Capital and Limulus Venture Partners, and existing investors New Enterprise Associates, Novartis Venture Fund, Morgenthaler Ventures, and Amgen Ventures also participated.

These crossover rounds have become commonplace in biotech as money has flooded back into the sector. Another Cambridge biotech, RaNA Therapeutics, just announced a $55 million crossover round earlier this morning.