Vaccine for cancer finds a patron

In an unusual effort by a single wealthy investor to keep a medical idea alive, a German billionaire is promising $50 million to Therion Biologics Corp., a small Cambridge company trying to develop the first-ever therapeutic vaccine for cancer.

Company officials are scheduled to disclose tomorrow that Hans-Werner Hector, founder of German software giant SAP AG, will offer Therion a fresh influx of cash to push the company through its next two years of development, including a possible application to the Food and Drug Administration for its vaccine next year.

Hector is already the firm's major investor, having sunk $94 million into Therion since reading about the company's struggles in a newspaper article in 2001.

''How often does one individual OK the creation of a drug program . . . and see it all the way through to the licensing? I really don't think it's ever been done," said Mark Leuchtenberger, Therion's chief executive. ''It's a story of a modern Medici, one person attempting to change the treatment landscape for cancer."

Therion, headquartered in a former twine factory in East Cambridge, is one of a handful of biotechnology companies nationwide competing to develop a therapeutic cancer vaccine -- an idea with long scientific roots that has never yielded an approved treatment.

Its lead product, Panvac-VF, is a series of injections designed to fight pancreatic cancer, which strikes 30,000 Americans each year and is almost always fatal.

Early tests of Panvac showed it extended the lives of patients with late-stage pancreatic cancer, and the company expects results from a larger trial on 250 patients early next year. If it shows significant benefits, the company will apply for FDA approval.

''We're all figuratively holding our breath waiting for the results of this trial," said Leuchtenberger.

Like shots for flu or measles, cancer vaccines are designed to train the body's immune system to fight a specific disease.

Unlike a traditional vaccine, however, the drug being tested by Therion is not preventive. Rather, it is given to people who already have cancer, in the hopes that their immune cells can learn to recognize and attack the cancer as it tries to grow and spread in the body.

A success in the trial would let Therion enter the lucrative niche of last-chance cancer therapies, among the most expensive drugs in modern medicine.

It would also cap a remarkable 15-year transformation for Therion, started in the early 1990s to develop AIDS vaccines.

By 2002, the company had 50 employees and was branching into cancer treatment, but had never produced a drug and faced the prospect of running out of money.

Hector, a German mathematician who helped found one of the world's largest business software companies, read about the financial struggles of Therion's founder, Dennis Panicali.

Through his investment firm, Hector led a fresh round of venture capital and hired Leuchtenberger, then a Biogen executive, to be the new chief executive. Panicali stayed on as the head of scientific research.

Since then, Hector, who has also endowed a foundation to support cancer and AIDS charities, has sat on the board and now controls the majority of the company. He could not be reached for this story.

Hector's involvement made Therion's survival possible at a time when traditional sources of cash, such as venture capitalists and the public markets, were showing little enthusiasm for unproven technologies, said Leuchtenberger.

''It's clear there's been skepticism about cancer vaccines, and there have been some disappointments in the field, and that's what makes Mr. Hector's support even more extraordinary," he said.

The idea behind cancer vaccines has been around for decades. The immune system is geared to attack outside invaders like viruses, but normally ignores cancer cells because they originate inside the body.

Vaccine researchers try to find small ''markers" that set cancer cells apart from normal body cells, then teach the immune system to recognize those markers and attack the cancer.

The idea has spawned numerous small trials on cancer patients in the last decade, and triggered great enthusiasm among scientists. Dana-Farber Cancer Institute launched a cancer vaccine center earlier this year, which now has around 30 affiliated researchers and staff members.

Dr. Stephen Hodi, who directs the skin-cancer program at Dana-Farber, calls the field a ''roller coaster," but said it has benefited from recent leaps in the ability to monitor the immune system. It holds the promise of treatments far less harsh than chemotherapy.

''Many patients like the sense that their own body is doing something to fight the cancer," he said. ''Many of the vaccines are very well tolerated, and the hope is to have therapies that are nontoxic."

The field has proved frustrating for commercial vaccine developers, however, many of which have struggled to build on the promise shown in early trials.

Genzyme shifted efforts away from its cancer-vaccine program in the past year, and more recently the California company CancerVax Corp. slashed its workforce when tests of a promising skin-cancer vaccine failed.

A few companies in addition to Therion now have drugs in late-stage human tests. Antigenics Inc., with labs in Lexington, is testing vaccines on kidney and skin cancer; and Dendreon Corp., in Seattle, is testing a drug against prostate cancer. Both of those use the patient's own cells to engineer a customized vaccine.

Therion's vaccine, by contrast, would be an ''off the shelf" product, a standard preparation designed to work in all pancreatic cancer patients.

It works by identifying two proteins that are extremely common in pancreatic cancer cells, but rare in the rest of the body.

The company takes the genes that encode for those proteins and inserts them into harmless viruses used commonly to make vaccines. When injected into the patient, the altered viruses sensitize the immune system to those particular proteins, which in theory triggers an attack on the cancer without hurting other tissue.

The company creates the engineered viruses in a Cambridge lab, then walks them across the street to set of ''clean rooms" where the vaccine is grown in chicken eggs.

If the drug is approved, Leuchtenberger said, Therion is ready to produce enough for 10,000 to 15,000 patients -- and vindicate not only its owner's multimillion dollar investment, but decades of research around the world.

''I think we're all rooting for each other," Leuchtenberger said of vaccine companies. ''The skepticism around the field will be lifted when the first drug is approved by the FDA."

Stephen Heuser can be reached at sheuser@globe.com.