Prostate cancer patients may soon have a new treatment option: gold nanoparticles. Current treatments, such as radiation therapy or surgery, come with risks such as dangerous reactions to anaesthetics, uncontrolled bleeding, fatal blood clots, impotence, erectile problems and sepsis. To spare patients from such risks, a new clinical trial in the US is utilizing Aurolase nanoshell therapy to treat prostate cancer with minimal collateral damage to the surrounding tissue. To date, 11 patients have undergone the procedure, with highly promising results.

Naomi Halas from Rice University invented the Auroshells (or nanoshells) and collaborated with Duke University’s Jennifer West to apply this technology to the treatment of cancer. They co-founded the medical device company Nanospectra Biosciences to manufacture the nanoshells and expand their use in the medical field.

The team successfully demonstrated that Aurolase nanoshells were safe and effective in animal models of cancer, as a monotherapy or in combination with radiotherapy in the short term, and also in the long term for over one year.

The clinical trial begins

Martin Feeney was 70 years old when he was diagnosed with low-grade prostate cancer, but he delayed the standard-of-care, active surveillance treatment for 12 months because it would have required biopsies that could potentially have caused serious side effects. A year later, his cancer had advanced and he was faced with two treatment choices: whole-organ irradiation or removal surgery. Knowing the possible side effects for these treatments, he decided instead to enrol into the Aurolase clinical trial with Art Rastinehad at Mount Sinai hospital. The procedure still required surgery, but it would be minimal and mostly target the tumour tissue.

The Aurolase surgery pioneered at Mount Sinai utilizes MRI/ultrasound-guided ablation of gold nanoshell-loaded neoplastic lesions. The nanoshells – silica spheres with a gold shell – are delivered intravenously and accumulate in the tumour. MRI and ultrasound are used to locate the cancerous lesions as accurately as possible. Then a fibre probe that emits infrared light is inserted into the lesion. The nanoparticles absorb the light, converting it into heat that destroys the tumour while sparing adjacent tissue.

This treatment resulted in minimal side effects with no sign of relapse three months after Feeney’s procedure. Of the 11 patients who have now undergone this procedure, only two have shown adverse events, which were non-serious and self-resolving. The patients had prostate cancer lesions ranging between 0.23 and 3.28 cc in volume, and the average patient’s lesions had a Gleason score of 7 which characterizes non-aggressive, slow growing prostate cancer.

Elsewhere, Doug Flewellen, who was recruited for the trial by Steven Canfield at the University of Texas, has successfully undergone the procedure and is now in the follow-up period.

After tumour ablation using Aurolase nanoshells, all patients’ lesions were completely removed, proving thus far that this therapy is quite safe and a feasible treatment alternative to radiation and removal surgery. Furthermore, Rastinehad tells Physics World that 70% of patients have no signs of relapse at one year and that the trial will continue to recruit until next year.

 

Written by Dante Descalzi.