Two more Philadelphia-area biotech firms said Thursday morning they have raised a total of $115 million for expansion:

Apple Tree Partners, a New York biotech investor, has agreed to pump $75 million into Limelight Bio so that the Philadelphia firm, founded by a pair of University City doctors, can hire former Biogen Inc. research chief Michael Ehlers as chief executive and add other staff and resources to build what it calls “next-generation gene therapies” for eye, blood, brain, hearing, and other diseases.

Limelight, founded in 2017, is based at Pennovation, the University of Pennsylvania’s three-year-old campus for commercial research companies at the former DuPont Marshall Mills paint factory in South Philly’s Grays Ferry section, across the Schuylkill from Penn’s main campus.

Founders of the young company include gene therapists Jean Bennett of Penn’s Perelman School of Medicine, and Phil Johnson, former chief scientific officer at Children’s Hospital of Philadelphia.

Bennett is codirector of Penn’s Center for Advanced Retinal and Ocular Therapies (CAROT), which has an “exclusive relationship” to share science with Limelight.

Apple Tree, founded 20 years ago by the venture capitalist Seth Harrison, has backed a string of young biotech companies, including Exton-based ViroPharma Inc., purchased for $4.2 billion by Shire PLC in 2013.

A string of gene-therapy developers and other biotech firms have attracted private investors, and scores have conducted initial public stock offerings (IPOs) before posting their first profits — or even sales — in the last few years, spurred by the early success of start-ups like West Philadelphia-based Spark Therapeutics, which Roche agreed to buy last winter for $4.3 billion, pending regulators’ approval.

Philadelphia gene-therapy start-ups in particular have often been tied to pioneering techniques and narrow targets. Limelight founders claim a broader approach: “Gene therapy has made significant advances in recent years, and particularly gene replacement delivered by adeno-associated virus vectors or AAV. Yet, most genetic diseases are not addressed by this approach,” said Ehlers, the new CEO, in a statement.

Instead, Limelight is building what it calls “gene correction across unprecedented areas, including proprietary methods that persistently correct large genetic defects independent of gene size or mutation pattern without risk of permanent genomic alteration.”

Ehlers says Limelight’s gene-therapy platforms "could become the foundation for a new class of medicines.”

“Limelight Bio has the potential to leapfrog the prevailing gene-therapy and editing approaches to tackle a much broader array of genetic disorders,” added Harrison, of Apple Tree.

Besides South Philly, Limelight has labs in the biotech center of Cambridge, Mass.

Penn has filled the main Pennovation building with partner companies and start-ups and is clearing additional space in the neighborhood for new facilities.

Separately, Suvoda LLC, which builds clinical-trial software at its offices in Conshohocken, says it has raised $40 million from LLR Partners, a Philadelphia firm that invests for the Pennsylvania public school (PSERS) and state workers’ (SERS) pension funds and other clients.

Suvoda helps its drug and biotech clients manage new drug trials, including their supply chains, from initial investigator sampling through global Phase 3 trials. The company employs nearly 400 at offices in the United States and Europe, with customers in 62 countries.

LLR cofounder Howard Ross joins Suvoda’s board as part of the deal, Suvoda chief executive Jagath Wanninayake said in a statement.

Wanninayake’s team will “transform clinical trials” with its improved technology, Ross said in a statement.