Antigenics, and its UCSF Champion, Stick With Immune Booster For Brain Cancer
Antigenics could easily have thrown in the towel on its immune boosting therapy for cancer. But now the Lexington, MA-based biotech company, with the help of one of its main backers at UC San Francisco, is gearing up to run a significant trial to see if its lead therapy has a shot as a treatment for brain cancer.
The company (NASDAQ: AGEN) is announcing today it is expanding a mid-stage clinical trial of its experimental treatment vitespen (Oncophage) in 50 patients with newly diagnosed brain tumors (glioma). The trial, which started a year ago, was originally set up at three U.S. sites, and was expected to take two years to complete enrollment. Now, based on results that show the first eight patients were relapse-free for more than a year, Antigenics is pooling some of its money and resources to add six new clinical sites to see if it can recruit all the patients it needs a year ahead of schedule.
This could certainly be seen as the last-ditch hope for Antigenics and its personalized immune-boosting treatment for cancer. The treatment failed in a pivotal clinical trial for kidney cancer, although it showed a benefit in a subpopulation of patients that was enough for it to win market clearance in Russia. Still, the drug has been a commercial flop there, and Antigenics has been turned down in its bid to win approval for vitespen in Europe. The company had just $28 million in cash left at the end of its most recent quarter, and has a burn rate of about $15 million per year, says CEO Garo Armen.
With a stock price of less than $1 and limited ability to raise new capital, that meant that Antigenics either had to cut bait on vitespen and place its bet on a second candidate, QS21, or push forward aggressively to see if the early sign in brain cancer patients can be confirmed. And that’s what Antigenics chose—it now hopes to get solid data from this mid-stage glioma trial in the second half of 2011.
“We see this as our rebirth,” Armen says.
The only reason Antigenics is in position to even ask this question is because of the persistence of UC San Francisco neurosurgeon Andrew Parsa. It was Parsa who sought out the company about five years ago, asking for it to supply material to him for a clinical trial, which he said he would get federal grants to pay for. He ended up enrolling 32 glioma patients at UCSF, testing their immune system function as well as the gold standard measurement for any new cancer treatment—their overall survival time. Parsa found that patients had increased immune system activity after getting the Antigenics therapy, and that they lived a median of 44 weeks. There was no control group in the study, so it’s impossible to say how much better that was than no treatment at all, although historical life expectancy for relapsed glioma patients is about 26 weeks, Armen says.
While that’s not iron-clad proof of activity, it’s the sort of thing that sparks further study. So Parsa spearheaded a second trial, in newly diagnosed glioma patients who ought to have a better response to an immune therapy like the one from Antigenics. This study started out at three centers, but is now being expanded to nine centers to speed up enrollment, Armen says.
What makes the Antigenics treatment interesting is that it’s designed to be personalized, made by slicing out a portion of a patient’s tumor—a method unlike anything else on the market today. The tumor tissue is frozen and shipped to the Antigenics plant in Lexington, where it is chopped up, and key proteins filtered out. The protein treatment is shipped back to the doctor, then injected back into the patient to “teach” the immune system to spot the hallmarks of cancer cells and mount a defense against them. Patients usually get their personalized vaccine four to six weeks after tumors are removed, the company has said.
The company is hoping that if it gets more encouraging results by next year, it will be in a better position to move the program forward. The field of cancer immunotherapy—long plagued by anecdotal promise that couldn’t be verified in large, controlled trials—has undergone a resurgence. Seattle-based Dendreon (NASDAQ: DNDN) won FDA approval earlier this year for the first treatment to actively stimulate the immune system against cancer, and Bristol-Myers Squibb has presented promising data on a treatment that disables a defense mechanism tumors use to protect themselves from the immune system.
If Antigenics can stay afloat long enough to see promising results in the study of newly diagnosed glioma patients, it could have more room to maneuver. By that time, Bristol’s treatment, ipilimumab, could be on the market, and useful for a combination study, Armen says.
It won’t be an easy task. Antigenics, at last count, had accumulated a deficit of $576 million since it was founded in 1994, and today has a market valuation of about $95 million. But if Antigenics can get results a year from now that suggest it is keeping glioma patients relapse-free for more than a year, that would be the kind of thing that could spark chatter in the oncology community about another immunotherapy, and maybe help the company raise enough capital to run another test that would be robust enough to give Antigenics a shot with the FDA.
It was either that, or close down the vitespen (Oncophage) program, Armen says.
“The critical decision to be made is do we shut down Oncophage program or not?” Armen says. “Based on everything we’ve seen internal and externally, we are nowhere close to shutting down Oncophage. It will be pursued.”