A new drug-releasing system, TAR-200, eliminated tumors in 82% of patients in the phase II SunRISe-1 trial (ClinicalTrials.gov identifier NCT04640623) for individuals with high-risk non–muscle-invasive bladder cancer whose disease had previously resisted treatment. In the majority of cases, the cancer disappeared after 3 months of treatment, and almost half the patients were cancer-free 1 year later.
“Traditionally, these patients have had very limited treatment options. This new therapy is the most effective one reported to date for the most common form of bladder cancer,” said Sia Daneshmand, MD, Director of Urologic Oncology at Keck Medicine of USC and lead author of a report detailing the results published in the Journal of Clinical Oncology. “The findings of the clinical trial are a breakthrough in how certain types of bladder cancer might be treated, leading to improved outcomes and saved lives.”
More on TAR-200
TAR-200 is a miniature, pretzel-shaped drug-device duo containing the chemotherapy gemcitabine, which is inserted into the bladder through a catheter. Once inside the bladder, the TAR-200 slowly and consistently releases gemcitabine into the organ for 3 weeks per treatment cycle.
Traditionally, gemcitabine has been delivered to the bladder as a liquid solution that stays in the bladder for a few hours, which had limited effect destroying the cancer, said Dr. Daneshmand, who is also a member of the USC Norris Comprehensive Cancer Center.
“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,” he said. “And it appears that having the chemotherapy released slowly over weeks rather than in just a few hours is a much more effective approach.”
SunRISe-1
The phase II SunRISe-1 trial was conducted at 144 locations globally. It included 85 patients with high-risk non–muscle-invasive bladder cancer. The standard treatment of this type of bladder cancer is an immunotherapy drug, bacillus Calmette-Guérin (BCG), which may be ineffective in a percentage of patients. All patients in the clinical trial had been previously treated with BCG, but their cancer had returned.
“The standard treatment plan for these patients was surgery to remove the bladder and surrounding tissue and organs, which has many health risks and may negatively impact patients’ quality of life,” said Dr. Daneshmand.
To offer patients a better option, urologic oncologists treated patients with TAR-200 every 3 weeks for 6 months and then four times a year for the next 2 years. In 70 of the 85 patients, the cancer disappeared, and for almost half the patients, it was still gone 1 year later. The treatment was reported to be well tolerated, with few side effects.
The study also showed that administering TAR-200 along with the monoclonal antibody cetrelimab did not prove as effective as TAR-200 on its own and resulted in more side effects.
Although participants in the clinical trial will be followed for another year, the study is closed to new participants.
The Future of Slow-Release Systems
This clinical trial is one of several ongoing ones investigating the effect of TAR-200 and the slow release of cancer-fighting drugs into the bladder to fight cancer.
“We are at an exciting moment in history,” said Dr. Daneshmand, who has been researching this novel treatment since 2016. “Our mission is to deliver cancer-fighting medications into the bladder that will offer lasting remission from cancer, and it looks like we are well on our way toward that goal.”
The U.S. Food and Drug Administration has granted TAR-200 a new drug application Priority Review.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.
