November 17th, 2011
01:38 PM ET
It appears that the economy, not controversy, is shutting down the first clinical trial to use cells derived from human embryonic stem cells in humans. Due to the "current environment of capital scarcity and uncertain economic conditions," Geron CEO Dr. John Scarlett said his company will be focusing on developing cancer treatments instead.
In January 2009, after many years of research, Geron became the first company to get FDA approval for human trials using cells grown from human embryonic stem cells. The the FDA asked for more research, which led to final approval in July of last year. Three months later, a 21-year-old nursing student from Alabama became the first human to be injected with these cells.
The purpose of this trial was to determine safety. Embryonic stem cells have the ability to turn into any type of cell. Cells that had been coaxed into becoming nerves cells were injected into patients who had just suffered a spinal cord injury that paralyzed them from the chest on down. Patients had to receive these injections within two weeks of being paralyzed.
Geron had FDA approval to test at least eight patients, to see whether the injections were safe and could be tolerated by patients. So far four patients had received injections. Any other patients who had already consented to participating could still be part of this clinical trial, says Scarlett.
Dr. Stephen Kelsey, Geron's chief medical officer and head of research and development, says that the cells have been "remarkably well tolerated" but that they have not received any information about their impact on the patient. "We have not observed any neurologic function at that stage," he says.
Experts in the field agree that Geron paved the way for other companies to seek FDA approval for embryonic stem cell trials. Shortly after Geron's trial began, the FDA approved the second clinical trial using cells derived from human embryonic stem cells for a different company, Advanced Cell Technology. In this case, cells are being injected into the eyes.
But on Monday, Geron, which received no federal funding, halted the 13-month-old trial, saying it was too expensive. "We will discontinue further development of our stem cell programs and are seeking partners for these assets," Scarlett said.
Geron's chief financial officer, David Greenwood, told investors and reporters Tuesday that stem cell-related research and development costs, if they were to continue, would total about $25 million per year for the next several years. So the company has to decided to focus instead on two cancer therapies that have moved further down the research pipeline than stem cells and will provide more shareholder value. "We anticipate having sufficient financial resources to reach these important near-term value inflection points for shareholders without the necessity of raising additional capital," says Scarlett.
One of these drugs, called imetelstat, blocks an enzyme that helps cancer cells grow. It's in Phase 2 clinical trials being tested in lung cancer, breast cancer and two blood cancers (essential thrombocythemia and multiple myeloma). Geron says results from these trials are expected by the end of next year.
The other therapy is called GRN1005, and first results for safety trials (phase 1) were presented at a cancer conference on Tuesday. GRN1005 is meant to treat brain cancer that has spread from other parts of the body, by binding an already-approved cancer drug called Taxol to a protein. This combination would allow the cancer drug to cross the blood-brain barrier, something that Taxol alone can't do, according to Scarlett. Study results show that this combination drug was safe and well tolerated by the patients, "with encouraging evidence of anti-tumor activity against brain metastases," according to a company press release.
With the cancer drugs further down the research pipeline, Geron is now looking for a partner to take over the stem cell program, which not only includes research into spinal cord injuries, but also heart disease, diabetes and cartilage damage. While Geron will not enroll any new patients, whoever invests in this branch of the company could choose to do so, executives say. It all depends on what final deal is made.
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