Provenge is a promising new therapy made by Dendreon for certain types of prostate cancer. It has shown strong efficacy to date in several studies, but concerns about how it is made played a large role in the FDA asking for more data on it in 2007. It is up for another FDA examination later this year.
Provenge is made using your body’s own immune cells. To do so, you are hooked up to a machine which filters out certain cells from your blood. Those cells are then taken to a lab where they are exposed to certain elements that are a significant part of prostate cancer. This trains them to attack those elements.
After this training, the cells are infused back into your body. The whole process typically takes 3 injections over the course of a month.
The number one question people have about any treatment is, how well does it work?
The data increasingly shows that Provenge increases lifespan, or objective survival rate, in those who take it. In one study of 127 patients, those who took Provenge lived an average of 4.5 months longer than those given placebo. Additionally, those on Provenge were three times as likely to be alive 3 years after the start of treatment compared to placebo.
That said, the exact types of prostate cancer that best benefit from Provenge have not fully been figured out yet.
FDA Asks for More Data
When Provenge was submitted for FDA approval in 2007, it had the strong approval of an advisory committee. The FDA decided to ignore the advisory committee’s opinion possibly due in part to three letters written to it attacking Provenge.
One of the key elements was pointing out that the studies into Provenge had not met their primary objective, of reducing the time that the prostate cancer took to progress. Improving the objective survival rate was not the primary goal of the study so the studies were, arguably, a failure.
Considering that patients on Provenge lived a significantly longer time than those not, this decision outraged many. Some argued that unseen political maneuvering was preventing a lifesaving medication from reaching market.
To placate the FDA, there has been an additional study run with the primary goal of increasing lifespan of those on Provenge. This goal has been met with the latest study showing an increase in survival of around 4 months and an increase of 38% in chance of being alive at three years – for those taking Provenge.
Less than 3% of patients are unable to complete all three infusions due to side effects. There are similar rates of side effects in people on Provenge and on placebo.
All side effects that were considered serious resolved within 24 hours and all patients recovered.
57% on Provenge report chills
48% report fatigue
32% report pyrexia or fever
19% report headache
14% report asthenia or weakness
14% report nausea
13.6% report anemia
13% report paresthesia or tingling sensation
11% report chest wall pain
11% report dyspnea or shortness of breath
11% report vomiting
The data indicates that there may be some increase in cerebrovascular events such as stroke in patients on Provenge. One study indicated a higher rate of such incidents on those on the medication. Due to the small numbers of participants, however, it is possible that the higher rate was in part from normal statistical variation.
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