Sutent – an exciting new cancer treatment
Sutent, generic sunitinib, is a new cancer medication that has quickly become accepted as a first line treatment for renal cell carcinoma (RCC) as well as a treatment for gastrointestional stromal tumor (GIST) after resistance to imatinib develops.
It is being investigated for other uses as well, like for treating breast cancer.
Sutent is a tyrosine kinase inhibitor and acts on multiple sites. This is important because dysregulation of tyrosine kinases is a common factor in the development of cancer as they play a major role in regulating cell proliferation.
Sutent seems to have especial impact on tryosine kinases mediated by Von Hippau Lindau factor, which is involved in release of factors like VEGF, EGF, and other cancer favorable factors. Abnormalities in that pathway are often associated with renal cell carcinoma.
Other factors Sutent may play a role in lowering activity of include PDGF and fetal liver tyrosine kinase receptor.
This diverse spectrum of effects may make Sutent a useful treatment for different types of cancer. On the other hand, it also means that side effects are somewhat more common on it than similar medications.
Sutent for Renal Cell Carcinoma
The standard treatment for renal cell carcinoma (RCC) has been a combination of interferon-alpha and interlukine-2. These are both messengers that the body has already, and by providing them, you hope to prompt the body into a strong response against the tumor. We’ve been forced to use that treatment because standard chemotherapies, unfortunately, do not work that well as this type of cancer is highly resistant.
It doesn’t work that well, with only 10-20% response rates.
A recent study that compared Sutent to standard therapy showed a superior 11 months of time for disease progression compared to 5 months for those treated normally. This study additionally also showed a significant survival benefit.
One study that looked at Sutent use in those who failed or were not eligible for cytokine treatment showed a significant 40% primary end point response with some shrinkage in almost everyone. That said, 33% had disease progression at 3 months.
Sutent for Gastrointestional stromal tumor
For this type of tumor, the typical treatment has been imatinib, a related medication that also is highly effective. Resistance, however, tends to develop with time, and researchers wondered if Sutent might be effective as a back-up option.
The studies have again been fairly positive.
A recent study that compared Sutent to no treatment in this use was stopped in the middle because of how effective it was. Those who were using Sutent had roughly 27.3 weeks before their disease progressed, compared to only 6.4 weeks for those using standard treatment.
On the basis of this and other studies, sunitinib has become a standard backup treatment for GIST when imatinib stops working.
Sutent Side Effects
The side effects of Sutent are significant and common. In one study in treating RCC, everyone had some sort of side effect. Remember, Sutent is fairly non-specific. That means it effects many other tissues beyond the cancer.
Sid effects include neutropenia and lymphopenia, or depletion of certain types of immune cell. Alopecia, hair loss, or hair color change is not uncommon. Other common side effects include headach and asthenia, or loss of strength.
Somewhat rarer are hypertension and rash,
Use of Sutent may cause electrolyte imbalances including hypokalemia.
The standard treatment plan is to use 50mg per day for 4 weeks, with two weeks off. And so on.
Other medication dosing options being explored include 50mg daily for 2 weeks with one week off. Additionally, it may be possible to take 37.5mg as a continuous daily dose.
As always, follow your doctor’s instructions.
Sutent is metabolized by the CP450 3A4 system and may interact with other medications that use that pathway. The drug does not seem to be significantly effected by the foods you consume.