ASCO Weekend Highlights: ImmunoGen, Antigenics, Aveo Show Off Cancer Drug Findings
There were hundreds of companies vying for the attention of 30,000 cancer specialists the past couple days at the American Society of Clinical Oncology meeting in Orlando, FL. Here’s a quick recap of highlights from New England companies that have presented data so far. The conference continues today and tomorrow.
—ImmunoGen: The Waltham, MA-based biotech (NASDAQ: IMGN) has developed technology to make a “souped-up” version of Genentech’s and Roche’s trastuzumab (Herceptin) for breast cancer. This product, called trastuzumab DM1 or TDM1, aims to make the original antibody drug more potent by attaching a tumor-killing toxin to it.
One out of four patients (25 percent) who got the experimental drug had partial or complete tumor shrinkage, according to a final analysis of the trial cited by ImmunoGen in a statement. That figure was impressive, because the trial involved patients whose cancer had spread and who had relapsed after taking the original Herceptin. More than half had also relapsed after taking a competing drug from GlaxoSmithKline, lapatinib (Tykerb). The most common severe side effects were lowered potassium levels, and lowered counts of platelet cells in the blood, although researchers didn’t see the heart damage that has been observed in other Herceptin trials.
A preliminary look in December at the data from 107 patients suggested this drug might be doing even better—with 40 percent showing partial or complete tumor shrinkage after taking the drug. One difference is that the final numbers on tumor shrinkage were judged by an independent review facility—not the treating physicians who might be inclined to see something positive that isn’t there.
Regardless, Genentech and Roche considered these results intriguing enough to begin a 580-patient global clinical trial last February to hopefully amass enough proof to bring TDM1 to the market.
—Antigenics: The Lexington, MA-based biotech company looked back in time at a clinical trial of its immunotherapy for kidney cancer, and found some evidence that it may be helping people live longer. This trial failed in its original goal of lowering the risk of cancer recurrence after kidney tumors were surgically removed, which is enough for many biostatisticians and physicians to write it off.
But the company (NASDAQ: AGEN) has persisted, saying that its drug, vitespen (Oncophage), actually did lower the risk of recurrence for about 60 percent of patients with intermediate risk of relapse—and that it now appears that those same patients had a 46 percent lower risk of dying, based on an interim analysis of patient records from 362 of the 604 subjects who enrolled in the trial. It will take another nine months of record-gathering and follow-up for the company to complete a final analysis of the data, but CEO Garo Armen hopes this will at least strengthen the company’s pending application to market Oncophage in Europe.
—Aveo Pharmaceuticals: The Cambridge, MA-based biotech released some intriguing data on a new kind of drug it’s developing to cut off blood supply to tumors. In a mid-stage clinical trial of 272 patients with advanced kidney cancer, this drug, tivozanib or AV-951, was able to at least partially shrink tumors for one-fourth of patients, and keep the cancer from spreading for a median time of 11.8 months.
Aveo’s drug is designed to be a more selective blocker of certain types of VEGF receptors, which are involved in forming new blood vessels to nourish tumors. Researchers are hopeful that by being more selective, this drug might be able to avoid hitting similar receptors on healthy cells and causing the side effects seen with some other drugs that work this way. This trial showed minimal side effects, which is encouraging, says Robert Motzer, a kidney cancer expert at Memorial Sloan-Ketting Cancer Center in New York.
If this can be proven in a pivotal clinical trial, Aveo hopes to tap a lucrative market that sees 54,000 new kidney cancer patients diagnosed in the U.S. each year. The company would be in a position to compete with Pfizer’s sunitinib (Sutent) and Bayer and Onyx Pharmaceuticals’ sorafenib (Nexavar).
—Infinity Pharmaceuticals. The Cambridge, MA-based developer of cancer drugs (NASDAQ: INFI) released data that suggests its lead drug candidate, IPI-504, has some ability to shrink tumors and is well-tolerated. This drug is interesting to researchers because it’s made to block a protein called heat shock protein 90, or Hsp90, that serves to aid the growth of tumors.
Infinity found that four out of 28 patients with late-stage lung cancer and a normal version of a tumor-growth protein called the EGF receptor saw their tumors shrink after taking IPI-504 without any supporting chemotherapy. None of the 19 patients in the study with a mutated form of the EGF receptor had tumor shrinkage, researchers said. Based on the finding, Infinity plans to continue studying genetic characteristics to try to identify patients most likely to respond to treatment.
That’s one strategy to go forward after Infinity suffered a big setback last month with this drug. A pivotal trial of patients with gastrointestinal stromal tumors, a malignant type of stomach cancer, was halted early after interim results showed patients who were taking the drug had a higher risk of death than those in the control group.
—Synta Pharmaceuticals. The Lexington, MA-based biotech company (NASDAQ: SNTA) suffered a devastating setback in February. The company halted a clinical trial of 630 patients with melanoma that had spread through the body, after learning that patients who took its experimental drug along with paclitaxel chemotherapy had a higher risk of dying than those who got paclitaxel alone.
The study failed to reach its primary goal of slowing the spread of melanoma, researchers said. But even though the death rate was higher in the group who got the drug, the rate of side effects looks remarkably similar between those patients and their counterparts in the control group. The rates of hair loss, fatigue, nausea, diarrhea, constipation, headache, rash, and vomiting were all within a few percentage points of each other—so it’s hard to point to what might have been leading to the higher death rate. Synta didn’t present hard numbers comparing survival time between the two groups, but it said more follow-up is needed before the survival data can be considered mature. That should happen by the end of 2009 or early 2010, the company said.