Celldex Therapeutics Inc. (NASDAQ: CLDX) announced it would suspend a late-stage study of its brain cancer vaccine because results of an independent interim analysis revealed that the therapy might not offer a significant benefit in patient survival compared with standard chemotherapy in terms of statistical advantages.
The vaccine involved, Rintega, is one of the latest types of drugs that stimulate the human immune system to recognize and fight cancer. Rintega targets tumors with a genetic mutation found in a third of all cases of glioblastoma multiforme (GBM), which is the most common and deadliest form of brain cancer. This means that roughly 4,000 patients would benefit from it in the United States, according to a report by Reuters.
GBM tumors usually become resistant to initial treatment quickly. Experts say the median survival rate for patients who have just been diagnosed is around 14-15 months if they are receiving standard chemotherapy like Temodar by Merck & Co.
An independent data safety and monitoring board carried out an interim analysis and found that the overall survival rate in patients with newly-diagnosed GBM who took Rintega was on a par with those who were given standard chemotherapy.
Celldex, whose shares more than halved to $3.76 in premarket trading on Monday, announced it was discontinuing the study on the board’s advice and said it did not expect to pay substantial extra expenses.
Results from a mid-stage trial of 73 patients conducted last year showed that the combination of the vaccine and the standard therapy helped patients with a recurrent form of GBM live longer than without Rintega.
Celldex had rushed to use the data to quickly get approval for the vaccine, but it waited for a late-stage study data before filing a marketing application on the advice of the U.S. Food and Drug Administration.
Some patients could still have access to the vaccine
The firm is still reviewing the interim analysis, but David Nierengarten, a Wedbush Securities analyst, told Reuters that the company was unlikely to continue developing Rintega. However, the vaccine, which has the “breakthrough designation” by the FDA, will still be given to GBM patients who choose it under a compassionate use program.
This means that Celldex will provide Rintega to patients who decide to take it after talking to their doctors and evaluating the severity of their condition and the stage of their disease.
People taking an investigational drug for a life-threatening illness must be aware that the medication has not been approved by the FDA and that the likelihood that the therapy will be effective is rather uncertain. Patients and doctors need to consider all the possible risks before seeking access to this kind of medical products.