New pretzel-shaped device cured 82% of bladder cancer patients

There’s a new twist in the fight against bladder cancer — and it’s delivering game-changing results.

In a recent clinical trial, a pretzel-shaped device that slowly releases chemotherapy drugs directly into the bladder eliminated tumors in 82% of patients whose cancer had resisted standard treatment.

For most, the cancer vanished within three months, and nearly half remained disease-free a year later.

Dr. Sia Daneshmand, director of urologic oncology with Keck Medicine of USC and lead author of a study, said called the finding a “breakthrough” in how certain types of bladder cancer might be treated.

Each year, more than 80,000 people in the US are diagnosed with bladder cancer.

The most common type is non-muscle-invasive, where the disease remains in the bladder’s lining and hasn’t reached the muscle layer. When features like high-grade tumors increase the chances of recurrence or progression, it’s classified as high-risk.

For these patients, treatment often involves the immunotherapy drug Bacillus Calmette-Guérin (BCG). Delivered through a catheter into the bladder, it typically stays in place for a few hours, stimulating the body’s immune system to attack cancer cells.

But BCG isn’t effective for everyone. Studies show that up to 40% of patients either don’t respond initially or see their cancer return.

That’s meant treatment progressed to removing the bladder and surrounding tissue and organs. To offer a less invasive alternative, researchers developed the TAR-200.

Like BCG, this small, pretzel-shaped device is inserted into the bladder via catheter, where it slowly releases the chemotherapy drug gemcitabine over three weeks per treatment cycle.

“The theory behind this study was that the longer the medicine sits inside the bladder, the more deeply it would penetrate the bladder and the more cancer it would destroy,” said Daneshmand, who has been researching the treatment since 2016.

It worked. Daneshmand’s team treated 85 patients with high-risk non-muscle-invasive bladder cancer who had relapsed after BCG therapy. In 70 of the 85 patients, the cancer disappeared. For almost half the participants, was still gone a year later. 

That’s significant, because patients often relapse within a year of standard treatment, and many become unresponsive to further therapies.

The most common side effects were mild urinary symptoms — like frequent urination, burning, urgency and urinary tract infections — which usually resolved within weeks.

“This new therapy is the most effective one reported to date for the most common form of bladder cancer,” said Daneshmand.

Several clinical trials are currently underway exploring TAR-200, made by Johnson & Johnson, and its slow-release delivery of chemotherapy into the bladder.

In July, the FDA granted it priority review status, aiming to complete the review within six months instead of the usual 10.

“TAR-200 represents an innovation in drug delivery that has not been seen in decades,” Dr. Yusri Elsayed, global therapeutic area head of oncology at Johnson & Johnson Innovative Medicine, said earlier this summer.

“The FDA Priority Review for TAR-200 underscores our mission to fundamentally change the way urologists treat certain types of bladder cancer.”

Bladder cancer ranks as the 10th leading cause of death in the US, with an estimated 17,420 deaths expected in 2025, according to the American Cancer Society.

The disease is more common in men than women, though incidence rates have declined by about 1% annually for both sexes in recent years. This drop is likely linked to decreased smoking rates, the leading risk factor for bladder cancer.