Indeed, Penn entered a much-publicized partnership with the global pharmaceutical giant Novartis in 2012, based on results from just the first three leukemia patients.
Penn's T-cell therapy and its development deal are at the heart of the lawsuit that Juno Therapeutics has joined.
Juno, based in Seattle, is a partnership of Sloan-Kettering, Fred Hutchinson Cancer Research Center, and Seattle Children's Research Institute. Last month, Juno signed a licensing agreement to commercialize T-cell technology patented by St. Jude Children's Research Hospital in Memphis, according to legal papers.
The technology involves a "chimeric antigen receptor," or CAR - a synthetic genetic structure that programs the patient's T cells to target and attack cancer.
St. Jude is suing Penn, accusing the university of breaching an agreement to share St. Jude's CAR and infringing on St. Jude's patent.
On Dec. 18, a federal judge granted Juno permission to intervene in the lawsuit, which seeks financial compensation and an end to the patent infringement.
"The license agreement between Juno and St. Jude explicitly provides that Juno will 'control, pursue, and defend' the present case between St. Jude and Penn," attorneys for Juno wrote in legal papers.
Lawyers for the parties said they could not comment on pending litigation.
They are scheduled to meet on Jan. 28 with U.S. District Judge Stewart Dalzell in Philadelphia to discuss settling the case without a trial, according to court filings.
Penn's research team, led by gene-therapy pioneer Carl June, was not the first to test a CAR therapy in humans, but it was the first to report a breakthrough.
In 2010, Penn's version unexpectedly eradicated the cancer of the first patient to try it, a 64-year-old man with end-stage leukemia who had exhausted conventional treatment options. He remains cancer-free.
Sloan-Kettering, Fred Hutchinson Cancer Research Center, the National Cancer Institute, and Baylor College of Medicine are among centers that have since reported success using CARs to activate T cells against cancers.
Several centers have formed industry partnerships, with the expectation that CAR technology can be adapted to attack common, solid tumors such as prostate and lung cancer.
Juno Therapeutics, for example, says on its website that it plans to develop "potentially revolutionary immunotherapy" against "a broad range of cancers."
While the website offers few specifics, the company's leadership and collaborators read like a Who's Who in Science. Juno's CEO is Hans Bishop, a biotech veteran and former executive of Dendreon Corp., maker of the prostate cancer immunotherapy Provenge. Juno's other cofounders include Richard Klausner, the former National Cancer Institute director, and Robert Nelson, managing director of ARCH Venture Partners, which arranged a chunk of Juno's $120 million start-up funding.
One of Juno's scientific founders is Renier Brentjens, a CAR researcher at Sloan-Kettering in New York City.
Ironically, while Sloan-Kettering has an interest in the success of Juno - and, thus, in the lawsuit against Penn - a Sloan-Kettering spokeswoman said it was going forward with a clinical study of CARs in collaboration with Penn. The study is designed to see which of the two centers has a superior CAR.
Collaboration was also what brought Penn and St. Jude together.
Penn's June heard a presentation by a St. Jude oncologist who had engineered a CAR to contain a T cell activation signal that no other researchers were using. That led to formal sharing agreements between St. Jude and Penn. Under those agreements, Penn was not allowed to commercialize any product using St. Jude's CAR without St. Jude's permission.
St. Jude filed suit against Penn in July 2012, not long after Penn partnered with Novartis. St. Jude's CAR patent was granted in March.
In legal filings, Penn argues that its CAR is significantly different from St. Jude's and that St. Jude's patent is invalid.
In November, the judge ruled that the original agreements between St. Jude and Penn were ambiguous, and, therefore, a jury would have to sort out the facts through a trial.
But such cases rarely go that far, legal experts say. The high cost of preparing for trial, the difficulty of educating juries about arcane science, and the pall of uncertainty that litigation may throw over a business create incentives for the parties to negotiate.
"For these and other reasons, more than 95 percent of intellectual-property lawsuits are resolved before trial, usually through settlement," according to Los Angeles-based Knobbe Martens, a large intellectual-property firm.