FDA Approval: Sunitinib (Sutent) for Kidney Cancer

A conditional yes, in January 2006

On January 26, 2006, the FDA approved sunitinib malate, sold as Sutent, in two separate applications on the same day.

One covered gastrointestinal stromal tumor. The other, NDA 21-968, covered advanced renal cell carcinoma, the main form of kidney cancer in adults. Only the kidney cancer decision was an accelerated approval.

The approval letter states the reason in one blunt sentence. Approval for advanced renal cell carcinoma rested on partial response rates and how long those responses lasted, and there were no randomized trials showing that Sutent increased survival or eased disease-related symptoms in kidney cancer.

That sentence is the whole story of what an accelerated approval is.

What renal cell carcinoma is

Renal cell carcinoma begins in the lining of the tiny tubes inside the kidney that filter blood and make urine. Our overview of kidney cancer covers the types.

Sunitinib is a multikinase inhibitor. Kinases are enzymes that pass growth signals inside cells, and this drug blocks several of them at once, including the ones tumors use to build new blood vessels. That places it in the family described in our guide to targeted therapy rather than in chemotherapy.

The evidence in 2006

Two single-arm studies supported the kidney indication. Single-arm means everyone got the drug and there was no comparison group.

Both enrolled people whose cancer had already failed cytokine treatment, the interferon and interleukin-2 drugs that were standard at the time. Across both studies, 95% had at least some clear-cell histology, 97% had already had a kidney removed, and 81% had cancer in the lungs. The median age was 57.

Study 1 enrolled 106 people. A quarter of them, 25.5%, had a partial response, meaning the tumor shrank substantially without disappearing. The 95% confidence interval ran from 17.5% to 34.9%. Responses lasted a median of 27.1 weeks.

Study 2 enrolled 63 people. Here 36.5% had a partial response, with a confidence interval from 24.7% to 49.6%, lasting a median of 54 weeks.

Nobody had a complete response in either study.

The trial that settled it

The confirmatory evidence came later, and it was a proper randomized trial.

Study 3 enrolled 750 people with advanced renal cell carcinoma who had not been treated before. Half got sunitinib and half got interferon alfa.

Median progression-free survival, the time before the cancer grew again, was 47.3 weeks on sunitinib against 22.0 weeks on interferon. The hazard ratio was 0.42, with a 95% confidence interval of 0.32 to 0.54.

Median overall survival was 114.6 weeks against 94.9 weeks, a hazard ratio of 0.821 whose confidence interval, 0.673 to 1.001, just touches 1. The label notes that 121 people on the interferon arm, 32% of it, later received sunitinib anyway, which blurs that comparison.

What taking it involves

The dose for advanced kidney cancer is 50 mg by mouth once a day for four weeks, then two weeks off. That is the "4/2" schedule.

That on-and-off pattern is the label's. Follow the calendar your own team gives you, because they often change both the amount and the rest week to keep side effects bearable.

The label's list of side effects reported by a quarter or more of patients is long: fatigue, diarrhea, mouth sores, nausea, loss of appetite, vomiting, abdominal pain, hand-foot syndrome, high blood pressure, bleeding, altered taste, indigestion, and low platelets.

It also carries a boxed warning, the FDA's most serious, for liver injury that can be severe and in some cases fatal. Liver function is monitored throughout. Other labeled risks that require monitoring include thyroid problems, low blood sugar, protein in the urine, and osteonecrosis of the jaw. Sutent is withheld for at least three weeks before planned surgery or invasive dental work.

When to get checked

Early kidney cancer often causes nothing at all. NCI says signs may appear as the tumor grows, and lists these as reasons to see a doctor:

• Blood in the urine.
• A lump in the abdomen.
• Pain in the side that does not go away.
• Loss of appetite.
• Weight loss with no known cause.
• Anemia.

Blood in the urine deserves a call even once, even painless, and even if it clears the next day.

The survival picture

Around 80,450 new kidney and renal pelvis cancers and 15,160 deaths are expected in the United States in 2026 — American Cancer Society projections that SEER reprints. Five-year relative survival across all stages was 79.2% for people diagnosed from 2016 through 2022.

By stage, SEER records 66% found while confined to the kidney, at 93.6%. Seventeen percent are found in nearby lymph nodes, at 77.6%. Fifteen percent are found after distant spread, at 20.3%.

Those figures pool everyone in the registry over several years. They are a description of a population, not a prediction for a reader.

What this approval cannot tell you

The 2006 decision measured tumor shrinkage in 169 people with no control group. Tumor shrinkage is not the same as living longer or feeling better, and the FDA said so in writing at the time.

The 2006 label was also written for people whose cancer had already failed cytokine therapy. Standard first treatment for advanced kidney cancer has changed since, and the drug's own label now also covers adjuvant use after a kidney is removed.

Nothing here establishes whether sunitinib is right for a particular person. Eligibility is set by the current label, and the choice belongs to a person and their oncologist.

Sources

• FDA approval letter for SUTENT, NDA 21-938 and NDA 21-968 (January 26, 2006)
• FDA 2006 prescribing information for SUTENT
• FDA prescribing information for SUTENT, 2021 revision
• Drugs@FDA overview: SUTENT, NDA 021968
• NCI PDQ: Renal Cell Cancer Treatment (Patient Version)
• NCI SEER Cancer Stat Facts: Kidney and Renal Pelvis Cancer

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

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