A breakthrough cancer protocol involving fourteen of the first 15 prostate cancer patients treated in a clinical trial of the gold nanoparticle-based, focal therapy showed no detectable signs of cancer a year after treatment, crossing a milestone in a decades long quest to develop a treatment that destroys tumors without the debilitating side effects of chemotherapy, invasive surgery and radiation.
The clinal trial research presents the results from 16 patients who were treated at the Icahn School of Medicine at Mount Sinai in New York. It is believed to be the first published clinical study of a photothermal cancer therapy, one that uses illuminated nanoparticles to heat and destroy tumors.
In the clinical trial , 16 men ages 58 to 79 with low- to intermediate-risk localized prostate cancer agreed to participate in a trial of AuroLase Therapy, a focal ablation treatment that uses gold nanoparticles to heat and destroy tumors. Fifteen of the 16 patients underwent the 48 hour treatment, receiving an intravenous infusion of nanoparticles on day one and undergoing an image-guided ablation treatment on day two. All of the patients went home on the day of the treatment and returned for follow-up tests at three months, six months and 12 months after treatment. Of the 15 who completed treatment, only one showed detectable signs of cancer in follow-up biopsies and MRIs one year later.
Lead Researcher, Assoc Prof. Dr. Ardeshir Rastinehad, commented in an interview with Thailand Medical News “Gold-silica nanoshell infusion allows for a focused therapy that treats the cancer while sparing the rest of the prostate, thus preserving a patient’s quality of life by reducing unwanted side effects, which could include erectile dysfunction and/or the leakage of urine.”
The clinical trial, which is ongoing and has treated 44 patients at Mount Sinai and two other clinical sites in Michigan and Texas, is the culmination of a 20-year quest by Rice University engineer and nanoscientist Naomi Halas and Duke University bioengineer Jennifer West. Halas and West, co-authors of the new study, first envisioned the nanoparticle-based therapy around 2000 while working together in Rice’s Brown School of Engineering.
The nanoparticles, tiny silica spheres with a thin outer layer of gold, are called nanoshells. They are about 50 times smaller than a red blood cell, and Halas invented them at Rice in 1997. By varying the thickness of the gold shell, Halas had shown she could tune nanoshells to interact with specific wavelengths of light. Around 2000, she and West invented a method of destroying cancer cells by heating nanoshells with a low-power, near-infrared laser that could pass harmlessly through healthy tissue. Halas and West had co-founded a Houston-based startup, Nanospectra Biosciences, to develop the technology for clinical use. At the time, Nanospectra was still conducting the necessary pre-clinical work to show that nanoshells could be safely used in humans.
Initially getting clinical trials approved by the US FDA was not easy, in part because the technology was groundbreaking. The team was the first to really engineered nanoparticle to In the end, the US FDA opted to regulate the treatment, which Nanospectra branded as AuroLase Therapy, as a medical device. Clinical trials focused on safety began almost 10 years ago with a study in late-stage head and neck cancer. But its usage in treating prostate cancer in men proved to be a successful milestone. Statistically 1 in 9 men are going to have to deal with prostate cancer their lifetime.
Reference: Ardeshir R. Rastinehad el al., “Gold nanoshell-localized photothermal ablation of prostate tumors in a clinical pilot device study,” PNAS (2019). www.pnas.org/cgi/doi/10.1073/pnas.1906929116