PhaseBio Pharmaceuticals Inc., a Malvern-based drug developer with a process for making drugs last longer in the human body so patients don't need multiple doses, has raised $34 million more from investors.

The fund-raising included $18 million in new cash to bring two blood drugs closer to market and the exchange of $16 million in debt held by earlier investors for new shares.

PhaseBio, which does not yet have products on the market, has raised a total of  $85 million since its founding in 2002 by Ashutosh Chilkoti, a Duke University medical scientist who developed elastin-like polypeptides (ELPs) to extend drugs' effective use from minutes to hours.

The company employs 20, and plans to add new staff with the cash. The new staff will help finish a Phase 1 proof-of-concept study and start a Phase 2 clinical trial for PhaseBio's leading drug candidate, known by its test name PB2452, a reversal agent used to stop patients from bleeding when they are on AstraZeneca's anti-blood-clot drug Brilinta (ticagrelor).

The company will also run a Phase 2 trial on weekly doses of a second drug, PB1046, which PhaseBio is developing to treat pulmonary arterial hypertension (high blood pressure in the lungs). That condition tends to affect women in their 30s and 40s. PB1046 work has been partly funded by a $2.8 million grant from the National Institutes of Health.

New investors include Cormorant Asset Management, Boston; Rock Springs Capital, Baltimore; and Mountain Group Partners, Nashville, all firms that focus on biotech and pharmaceuticals,  chief financial officer John Sharp said.

Besides the new investors, previous investors also bought into the latest round. They include New Enterprise Associates; Hatteras Venture Partners, whose partner Clay Thorp helped found PhaseBio and serves as executive chairman; AstraZeneca, the U.K.-based drugmaker whose U.S. headquarters is in Delaware; Johnson & Johnson Innovation-JJDC; Fletcher Spaght Ventures of Boston; and Syno Capital, which raises money in China for investments in U.S. health-care companies.

Why all the out-of-town investors? Because Philadelphia has lacked health-care-focused venture-capital investors, "we have to travel more," Sharp said. "We've met hundreds of investment firms." They don't care where the company is located, he said. "But we do have to fly around the country to see them."

PhaseBio was moved to Malvern from North Carolina by its previous chief executive, Chris Prior, in 2010. The current CEO, Jonathan P. Mow, is  based in San Diego, but most of PhaseBio's 20 employees work at its Malvern R&D center and offices.

Mow praised "the enthusiasm of our new and existing investors" in a statement. The firm also plans to explore "opportunities for our drug products outside of the U.S.," and prepare to develop new treatments, he added