Steba Biotech‘s TOOKAD treatment significantly reduces overall disease progression in men with low-risk prostate cancer, eliminating the need for most low-risk patients to undergo radical therapy, according to four-year follow-up data announced by the company.
Results from the study, “Randomized Trial of Partial Gland Ablation with Vascular-Targeted Phototherapy versus Active Surveillance for Low-risk Prostate Cancer: Extended Follow-up and Analyses of Effectiveness,” were published in the Journal of Urology.
In some cases, prostate cancer is diagnosed as low-risk, meaning the tumor is small and growing at such a low rate that it’s not viewed as life-threatening. These tumors do not warrant immediate treatment, such as radiotherapy or surgery, that could seriously impact the patient’s quality of life.
Instead, physicians usually recommend active surveillance (AS) or watchful waiting to monitor disease progression through regular checkups, including prostate-specific antigen (PSA) blood tests, digital rectal exams (DREs), and ultrasounds.
However, studies have shown that 25% to 60% of men on AS eventually switch to radical therapy within five to 10 years.
This prompted investigators to start looking for a more effective therapeutic option to control low-risk cancers that also posed minimal risks to patients’ urinary, sexual, or bowel functions.
Now, after a four-year follow-up period, researchers believe that partial gland ablation (PGA) with vascular targeted photodynamic therapy (VTP) could be the answer.
VTP is a noninvasive technique that works by using laser photoactivation to trigger cancer cell death while sparing healthy tissue. Researchers use a compound called TOOKAD (padeliporfin di-potassium), which is incorporated by malignant cells and releases toxic reactive oxygen species (ROS) when excited by infrared light.
With the safety and effectiveness of this technique already validated in Phase 1/2 trials (NCT00707356, NCT00946881, NCT00975429), researchers now wanted to see how it fared against active surveillance regarding disease progression in men with low-risk prostate cancer.
This was the primary goal of the multicenter, prospective, Phase 3 PCM301 trial (NCT01310894) that enrolled a total of 413 men with low-risk prostate cancer, randomly assigned to receive TOOKAD VTP or active surveillance.
After a four-year follow-up, researchers found that patients receiving TOOKAD VTP were less likely to require radical therapy compared to those on AS at two years (7% vs. 32%), three years (15% vs. 44%), and four years (24% vs. 53%).
End-of-study biopsy results were negative in 50% of the patients receiving TOOKAD VTP, compared to only 14% of those on AS.
Scientists are optimistic and believe that eliminating the need for most patients to undergo radical therapy is a meaningful clinical outcome for TOOKAD VTP, since it reduces treatment-related morbidity.
“Men need a much wider range of options for prostate cancer, a disease that we can now characterize with much more certainty than in the past,” Mark Emberton, a professor at University College London and principal investigator of PCM301, said in a press release.
“Precision therapies such as TOOKAD create a much-needed and welcome opportunity for men that want treatment but are unwilling to risk the harms associated with traditional radical therapies,” he added.
TOOKAD has been approved for commercialization in Mexico, Israel, and, in November 2017, in the E.U.
“Given prostate cancer is the most common cancer in men, it is critical that we provide patients with effective treatment options to help tackle their cancer early on, ” said Fabrice Harari, chairman and CEO of Steba Biotech. “With European approval of TOOKAD in November 2017, we look forward to making this important treatment option available to patients in Europe soon.”