Although chemotherapy is one of the go-to methods for fighting cancer, it often fails. New research published this week has revealed ways to potentially make cancer treatment more effective.
For example, the TAR-200 drug release system. According to University of Southern California’s Keck Medicine, this new system “eliminated tumors in 82% of patients in a phase 2 clinical trial for individuals with high-risk non-muscle-invasive bladder cancer whose cancer had previously resisted treatment.”
TAR-200 is described by Keck as a “miniature, pretzel-shaped drug-device duo,” that contains a chemo therapy drug (gemcitabine) that is inserted into the bladder through a catheter. It releases the chemotherapy drug slowly and consistently for three weeks.
“Traditionally, gemcitabine has been delivered to the bladder as a liquid solution that only stays in the bladder for a few hours, which had limited effect destroying the cancer, said Dr. Sia Daneshmand, a member of the USC Norris Comprehensive Cancer Center and lead author of a study on the system published last month in the Journal of Clinical Oncology.
Previous research has highlighted other drawbacks to chemotherapy. A study published in the European Journal of Pharmacology in 2023 found that “the most significant drawbacks of systemic chemotherapy are rapid clearance from the circulation, the drug’s low concentration in the tumor site, and considerable adverse effects outside the tumor.”
Daneshmand explained that his team sought to study what would happen if gemcitabine sat in the bladder for a longer period of time.
“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.”
Three weeks might seem like a long time for treatment, but Keck said the results happened fast. In the majority of cases, the cancer disappeared in just three months of treatment and almost half of the patients were cancer free within a year.
“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,” Daneshmand said. “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.”
Another recent study focused on bladder cancer also demonstrated how chemotherapy treatment could be more effective.
A team of researchers from Baylor College of Medicine analyzed 60 muscle-invasive bladder cancer (MBIC) tumor samples to figure out why some cancerous tumors resist chemotherapy. According to Baylor, only a quarter of patients with the condition “may be treated and derive a benefit with the current standard chemotherapy.”
Researchers used multiple types of analysis to study the samples, including: gene sequencing, analyzing genes turned on and off, studying proteins produced by the tumors, and looking at proteins with chemical tags to control their activity. Results were published in the Cell Reports Medicine journal.
“By computationally analyzing the vast information generated by the multi-omics approach, we produced a molecular profile for each tumor sample and hoped to uncover patterns linked to resistance to chemotherapy,” said co-first author Dr. Yongchao Dou, an assistant professor at Baylor.
Through their analysis, Dou and the team found certain proteins targeted by a new class of cancer drugs called antibody-drug conjugates (ADCs) in different patterns across tumor subtypes. This discovery indicates that the new drugs might be implemented along with chemotherapy or immunotherapy to improve treatment efficacy.
“The researchers also compared the molecular profiles in patients who had both pre- and post-treatment samples and found changes,” Baylor noted. “Some tumors changed their subtype after chemotherapy. They also found that certain proteins involved in cell recycling and energy use were more active after treatment, potentially helping the tumor survive.”
Dr. Seth P. Lerner, professor of urology and Beth and Dave Swalm Chair in Urologic Oncology and lead author of the research, said the findings are important because they provide “insights that can help expand the population that can be treated effectively and improve overall patient outcomes,” going forward.
“We were excited about the findings,” said Dr. Matthew V. Holt, director of the Lester and Sue Smith Breast Center Proteomics Laboratory at Baylor of the new research.
This year, more than 2 million new cancer cases are estimated in the U.S., per data from the American Cancer Society. An estimated 618,000 people will die from the disease this year and in a single year cancer-related medical costs can exceed $200 billion nationally.