Healthcare venture capital firm Third Rock Ventures said today it raised $616 million for its new oversubscribed Fund IV, which will support innovative healthcare companies.

The new investment round brings the total funding raised by the Boston-based venture capital firm to $1.9 billion, the group said.

“We appreciate the ongoing support from all the investors participating in Fund IV. Over the years, we have continued to build a leading investor base that is supportive of our unique model – a hands-on, team-based approach of discovering, launching and building great companies based on bold ideas that meet at the intersection of science, strategy, business and medicine. Our investment philosophy has always been shaped by the ongoing tremendous innovation in science and medicine. We aim to be both the preferred partner to scientific innovators from academia, and the preferred provider of innovative programs in important disease areas to address the bio-pharma industry’s pipeline needs,” Third Rock partner Dr. Robert Tepper said in a press release.

Third Rock has helped launch more than 40 healthcare companies. The firm said it focuses on “building product engine companies,” and that companies it has supported have delivered 4 products and 1 device to the market.

As part of the investment round, Dr. Abbie Celnicker is joining the firm as a partner, while venture partner Dr. Charles Homcy is being lifted to partner.. Dr. Frank Gentile, Dr. Stephen Sherwin and Dr. Barbara Weber will be taken on as venture partners.

“Without a doubt, people are the most important asset in our efforts, and I am incredibly proud of all that our team has accomplished to date. We are thrilled today to welcome Abbie and Charles as partners. Many of us have had the pleasure of working with them previously and know their insight and expertise will be invaluable as we continue to work collectively to translate the unprecedented level of innovation emerging from academia and industry to our company creation efforts,” Third Rock partner Alexis Borisy said in prepared remarks.

“I am delighted to be joining Third Rock. Having worked with many members of the team previously I have tremendous respect for their high-engagement, team-oriented and value creation driven approach. I am looking forward to contributing to ongoing efforts and long-term success as we continue to advance important science to build great companies to make a difference in the lives of patients and their families,” newly joined Third Rock partner Dr. Celniker said in prepared remarks.