As its lead product makes its way through a pivotal Phase III trial, Therion Biologics Corp. pulled in $30 million in a private equity financing.
If all goes well with the Panvac-VF trial in metastatic pancreatic cancer patients who have failed treatment with gemcitabine, the Cambridge, Mass.-based company could be positioned to file a biologics license application in 2006, said George Eldridge, Therion's senior vice president and chief financial officer.
"Currently, there is no drug approved for the treatment of second-line pancreatic cancer," he told BioWorld Today.
While front-line therapy consists of surgery, radiation, and chemotherapy with gemcitabine, when that fails, patients are treated with other single-agent chemotherapies to ameliorate the symptoms - not to extend survival.
"Unfortunately, gemcitabine has not been shown to extend survival for any significant period of time," Eldridge said, "and we are hoping our drug in second-line therapy will be able to extend survival."
The $30 million financing round was led by investor and philanthropist Hans-Werner Hector, who founded the enterprise software company SAP AG, of Walldorf, Germany. Other investors that participated were New York-based Loeb Investors, SRK Management Co. and Cheng Xin Venture Capital Group. All of them had previously invested in Therion, a company that has raised more than $100 million since its 1991 financing. It last raised $39 million in September 2003. (See BioWorld Today, Sept. 10, 2003.)
"The Series D round will finance the company to the end of 2005," Eldridge said, adding that the company may then consider the capital markets or conduct another private round.
The funds will be used for the clinical trials of Panvac-VF, as well as for the company's second product, Prostvac-VF. The first entered the pivotal Phase III trial in mid-2004 under a special protocol assessment with the FDA. (See BioWorld Today, May 24, 2004.)
The second product moved into a Phase II prostate cancer trial in late 2003. Therion expects to hit some crucial milestones in 2006, such as the BLA filing for Panvac-VF, and the initiation of pivotal studies for Prostvac-VF following Phase II results early in the year.
The company's technology is designed to selectively seek out and destroy malignant cells, without causing the side effects associated with cytotoxic chemotherapy. It has been evaluated for 13 years in more than 30 clinical trials involving about 1,000 patients, mostly through Therion's partnership with the National Cancer Institute.
Panvac-VF, for example, is designed to stimulate the immune system to target and destroy cancer cells expressing carcinoembryonic antigen (CEA) and mucin-1 (MUC-1), which are found on more than 90 percent of pancreatic tumor cells. The vaccine also incorporates Therion's triad of co-stimulatory molecules (B7.1, ICAM-1 and LFA-3), to enhance and sustain a targeted immune response. So far, both of the company's vaccines have been found to be well tolerated, with common side effects of injection site reactions, fatigue, chills and fever.
The Phase III trial of Panvac-VF is enrolling 250 advanced pancreatic cancer patients who will be randomized to receive the vaccine or a control treatment, such as capcitabine, irinotecan or 5-fluorouracil. Those in the treatment arm will receive an initial priming dose of Panvac-VF plus granulocyte macrophage-colony stimulating factor to initiate a cancer immune response, followed by a series of booster vaccinations to sustain a response. The primary endpoint is overall survival.
About 30,500 patients are diagnosed with pancreatic cancer, and about 29,700 die from the disease, in the U.S. every year.
"Unfortunately, the historical data show that once a patient arrives to second-line therapy that they, on average, live only about 90 days," Eldridge said.
The company's second vaccine candidate, Prostvac-VF, is based on the same technology platform as Panvac-VF, but it uses a gene for prostate-specific antigen inside its vectors.
Its Phase II trial is recruiting 120 men with metastatic prostate cancer who are hormone refractory. The primary endpoint is progression-free survival at 24 weeks. Results are expected early in 2006.
Neither of Therion's products are partnered, but the company might enter negotiations once each of the vaccines complete Phase III studies that "demonstrate sufficient efficacy to warrant commercialization of the products," Eldridge said.
Since pancreatic cancer is one of the toughest cancers to treat, a successful Phase III trial may pave the way for Therion's technology to be broadly used in a variety of cancers with the CEA and MUC-1 tumor markers, including breast, lung, ovarian and colorectal.
"If we were able to extend survival in second-line pancreatic cancer," Eldridge said, "the opportunity to show similar efficacy in other cancers makes the market opportunity for Panvac-VF very significant for the company and for the biotech industry."
Under a Cooperative Research and Development Agreement, Therion has worked with the NCI studying Panvac-VF and Prostvac-VF in the breast, lung, ovarian and colorectal cancer indications.
"It's the preliminary data from those trials that have made us very encouraged about the opportunity in these other cancers," Eldridge said.
In connection with the financing, Therion appointed Kathryn Davis vice president of clinical affairs, a new position that will oversee the late-stage clinical development programs. Davis most recently served as assistant vice president of clinical operations, research and development supporting translational research at Wyeth Corp. in Cambridge, Mass.