Third Rock Ventures Expands Senior Team with Seasoned Biotech Executives


- Jigar Raythatha Promoted to Partner -

- Mary Lynne Hedley, Steve Paul and Courtney Wallace join as Venture Partners -

- Vyas Ramanan promoted to Venture Partner -


BOSTON--(BUSINESS WIRE)-- Third Rock Ventures announced today that it has expanded its senior team with the addition and promotion of several industry leaders. Jigar Raythatha has been promoted to partner. Jigar, who joined Third Rock in 2021 as a venture partner, has made significant contributions to the firm’s discovery and company creation activities. In addition, the firm’s venture partner team has been expanded and now includes Mary Lynne Hedley, Ph.D., Steve Paul, M.D., Vyas Ramanan, Ph.D., and Courtney Wallace.

“One of Third Rock’s founding principles is the importance of collaboration and a philosophy of group genius. With this as a core value, we employ an evergreen approach to bringing together the best and brightest across the industry,” said Robert Tepper, M.D., partner at Third Rock. “We identify individuals who are leaders in their respective areas – scientific, strategic, financial, operational – to apply their insights and knowledge to our company build efforts. This group of individuals brings a vast amount of expertise and experience to their new roles at Third Rock and we are excited to have them on board.”

“We are delighted to have Jigar join the Third Rock partnership and fortunate to have someone with his expertise and enthusiasm in this new role. We have had the opportunity to work with Jigar for 15 years, as he has stepped into critical operational roles at a number of our portfolio companies including Jounce and Constellation, leading them to value creating events. Jigar shares our passion for creating companies that are focused on making a positive impact on the lives of patients,” said Abbie Celniker, Ph.D., partner at Third Rock. “At Third Rock, venture partners take a very hands-on approach, often serving in leadership roles in our portfolio companies, helping them to navigate the path to build sustainable, innovative, patient-focused biotechnology companies. We welcome Mary Lynne, Steve, Vyas and Courtney and have every confidence they will continue to make significant contributions in our efforts.”

“I am thrilled to be joining the partnership at Third Rock. Having worked closely with many members of the firm since 2009, I have gained great respect and admiration for the entire team and feel completely aligned with our mission,” said Jigar Raythatha, partner at Third Rock. “I am very excited to continue to lend my experience and insight to build great companies that develop innovative therapies to improve the lives of patients and their families.”

Jigar Raythatha is passionate about building great teams that can advance life-changing medicines. Prior to joining the firm, he held several leadership roles at Third Rock portfolio companies. He served as president and chief executive officer of Constellation Pharmaceuticals, Inc. from 2017 until its acquisition in 2021. Jigar also led the corporate development function at Constellation from 2009 to 2013. Jigar re-joined Constellation from Jounce Therapeutics Inc., where he held the role of chief business officer from the inception of the company through its IPO. Previously, Jigar worked with Red Abbey Venture Partners, initially, as a Kauffman Fellow and later as a principal and venture partner. Earlier in his career, Jigar held roles of increasing responsibility at Biogen and A.T. Kearney. He earned an MBA from Columbia University and a B.A. in biochemistry and economics from Rutgers University. Jigar is currently a member of the board of directors at Flare Therapeutics, Inc. and is also chairman of the board at TRIANA Biomedicines, Inc.

Mary Lynne Hedley, Ph.D., is a scientist by training who brings an enterprise-wide perspective to her thinking about new company formation and advancing therapeutic discovery and development. Mary Lynne was previously at TESARO, a company she co-founded and co-led prior to its acquisition by GSK. Mary Lynne received her bachelor’s from Purdue University, her Ph.D. in immunology from UT Southwestern and conducted post-doctoral fellowships at Harvard University.

Steve Paul, M.D., who has been affiliated with Third Rock since 2010, has re-joined as a venture partner. Steve has co-founded and led multiple neuroscience-focused companies, including Karuna Therapeutics, which was recently acquired by Bristol Myers Squibb, and Third Rock portfolio companies Sage Therapeutics, Voyager Therapeutics, and Rapport Therapeutics. Steve received his bachelor’s in biology and psychology from Tulane University, and his M.S. and M.D. from the Tulane University School of Medicine.

Vyas Ramanan, Ph.D., has been promoted to venture partner. Vyas joined Third Rock in 2016 and was most recently a principal where he has been involved in the firm’s discovery and company creation efforts. Vyas has been involved in the launch of several portfolio companies, including Maze Therapeutics. Vyas received a bachelor’s in economics and bachelor’s and master’s in bioengineering from the University of Pennsylvania. He earned his Ph.D. from Harvard-MIT’s Division of Health Sciences and Technology.

Courtney Wallace focuses on the formation, development, and strategy of Third Rock portfolio companies. Prior to Third Rock, Courtney was an early employee and the chief business officer of Beam Therapeutics. Earlier in her career, Courtney held roles of increasing responsibility at Celgene Corporation and Easton Associates, a healthcare consulting firm. Courtney holds an MBA from Harvard Business School and an AB from Harvard College.

About Third Rock Ventures

Third Rock Ventures is a leading healthcare venture firm focused on advancing disruptive areas of science and medicine to deliver breakthroughs to patients. By starting with big ideas and fostering collaboration among people with expertise in science, medicine, business and strategy, we aim to discover, launch and build innovative companies that can transform the lives of patients. Our mission is to be the preferred partner for entrepreneurs, investors, employees and industry to build great companies that discover and develop products that make a difference for the patients we serve. For more information, please visit


Corey O’Keeffe
Third Rock Ventures


Source: Third Rock Ventures

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