SUCCINCT

A Phase II single-arm trial to evaluate cisplatin and gemcitabine chemotherapy in combination with sunitinib for first-line treatment of patients with advanced transitional carcinoma of the urothelium.

SUCCINCT was a Phase II single-arm trial. The trial looked at a drug called sunitinib alongside chemotherapy for transitional cell cancer. It was for people whose cancer had grown into surrounding tissue (was locally advanced) or had spread to another part of their body.

Transitional cells (also called urothelial cells) are a part of the urinary system. The urinary system filters waste products from the blood and makes urine. Transitional cells line the centre of each kidney (renal pelvis), the bladder and the tubes that drain urine from the kidneys to the bladder (ureters), which means there is transitional cell cancer in the kidney, bladder or ureters.

If transitional cell cancer is locally advanced, or has spread to another part of your body, you may have chemotherapy. Doctors can treat transitional cell cancer with a combination of two chemotherapy drugs called cisplatin and gemcitabine. It is known as GC chemotherapy. However, survival rate is poor. Researchers want to improve treatment for this group of people, so in this trial they looked at having a drug called Sunitinib alongside GC chemotherapy.

Sunitinib is a type of biological therapy. It is a cancer growth blocker. It stops signals that cancer cells use to divide and grow. Date from other clinical trials demonstrates sunitinib to be highly active in other types of cancer, including advanced kidney cancer and rare types of stomach cancer. Early phase clinical trial data confirmed that sunitinib is active in urothelial cancer. Additional data also demonstrates that sunitinib can be safely combined with standard cisplatin based chemotherapy. Therefore, the SUCCINCT trial aimed to assess whether the addition of sunitinib to GC chemotherapy improves outcome for patients with advanced urothelial cancer.

The study aimed to recruit 63 participants from the UK. All trial participants were to receive a maximum of six, 21 day cycles of GC chemotherapy in combination with sunitinib (SCG).

The aims of the trial were to:

Find out if this combination of drugs helps people with transitional cell cancer of the urinary system;
Learn more about the side effects.

Participants were also asked to consent to the collection of tissue biopsy samples of their cancer, and blood samples before and after treatment, to gain a better understanding of the SCG combination.

If the results confirmed sufficient activity of the 3-drug sunitinib/cisplatin/gemcitabine chemotherapy, the combination treatment was to be taken forward into a larger randomised Phase III trial.

Results

63 people took part in the trial. Everyone taking part had the drugs cisplatin, gemcitabine and sunitinib. Six months after treatment finished the trial team looked to see whose cancer had come back. They had results for 58 people. They found the cancer had come back in 28 people and had not come back in 30 people. They also looked at the average overall time people lived for after treatment. They found that this was about a year.

The main side effect was a drop in blood cells causing an increased risk of infection, bleeding problems, tiredness and breathlessness. In some people these side effects took a long time to get better. This resulted in most people having their treatment reduced or stopped.

The trial team concluded that having sunitinb alongside GC chemotherapy was not a useful treatment for transitional cell cancer of the urinary system that had spread and it caused too many side effects. Based on this, they do not recommend this combination is looked at in future trials for this type of cancer.