Nanophotonics pioneer Naomi Halas, PhD, is one of the most recognized researchers in the field of nanotechnology, best known for her invention of nanoshells, a new type of nanoparticle with tunable optical properties especially suited for biotechnology applications.
Now her invention is bearing fruit via a company she and her nanoshell collaborator Jennifer West, PhD, founded. Nanospectra Biosciences (Houston) has commenced a pilot human trial of its AuroLase Therapy in refractory and/or recurrent head and neck cancers.
Of the hundreds of medical technologies and drugs incorporating nanotechnology that are in development today in the U.S., Clayton Teague, director of the U.S. National Nanotechnology Coordination Office (Arlington, Virginia) points to Halas' invention and Nanospectra's launch of a first-in-human trial as the brightest and most compelling example of the promise held via nanobiotechnology.
"I've followed this particular one carefully," Teague told Medical Device Daily. "The way they preferentially aggregate malignant cells and the very particular way they operate is a very pure form of nanotechnology in the sense that almost every aspect of the designing of nanoshells involves very careful control and dimension at the nanoscale. It's clearly an undisputable form of nanotechnology."
Interestingly, because the nanoshells are about 150 nm (a nanometer is smaller than bacteria or cells; most viruses, atoms and molecules are typically nanometer-sized), the FDA told Nanospectra President/CEO Donald Payne at the time of the Investigational Device Exemption (IDE) application that it would not classify the nanoshells as nanomaterials because it declared nanomaterials to be only those that are less than 100 nm. Thus the company is forbidden from officially marketing the product, should it succeed, as a nanomaterial.
"That came up in the context of our first discussion with the FDA," Payne said. "We didn't have a trade name yet, so that's when we decided to call them AuroShell particles [aurum is Latin for gold]. I guess the FDA needs some sort of cutoff in size. Everyone's definition may vary. Regardless, we don't expect any difference in the required FDA testing or scrutiny whether they call it a nanomaterial or not. And it doesn't matter to a patient if it's nanotechnology or not; it matters if it's efficacious and safe."
One of the reasons Teague and others have been so impressed by the pre-clinical performance of AuroShells is that there has been no evidence of dose-limiting toxicity in animal safety studies.
And, importantly, "We have seen that greater than 90% of treated tumors have a complete response," Payne said. Researchers at Nanospectra have followed the animals out to two years and there has been no recurrence of cancer.
The AuroLase therapy is designed to thermally destroy solid tumors using particles activated by a near-infrared laser. AuroShell particles, which have silica (glass) cores surrounded by ultra-thin gold shells, are injected into the bloodstream and allowed to accumulate in solid tumors through the leaky blood vessels related to the tumor's rapid growth.
Following this accumulation in the tumor, the area is illuminated with a laser that emits near-infrared light, a wavelength that has significant penetration through human tissue. The particles are designed to absorb this wavelength, converting the absorbed light into heat to thermally destroy the solid tumor.
The nanoshells, which are delivered in a one-time dose, are later cleared by scavenger cells and via the liver and spleen.
Because the nanoshells were invented by Halas, the Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry, and West, the Isabel C. Cameron Professor of Bioengineering, both at Rice University (Houston), nobody else in the world is working with the technology.
"We have an extensive portfolio related to nanoshells licensed to us from Rice. We're producing them in-house," Payne said. "It's not a difficult process. And the amount of gold that goes into a patient is worth about $35."
For the first human trial, the company's open IDE allows for the enrollment of up to 15 patients at up to four hospital sites in the U.S.
Three sites are currently participating in the trial: University of Texas Health Science Center (San Antonio), University of Texas Southwestern Medical Center (Dallas) and Baylor College of Medicine (Houston). The study is limited to patients who have recurrent disease or who have failed other therapies for soft-tissue tumors of the head and neck. In addition, there are specific eligibility requirements related to the health and condition of the patient.
Payne said AuroShells could potentially be used to treat any type of cancerous tumor. "We saw a significant unmet medical need for head and neck cancer," he said. "There's a large population of patients with recurrent and refractory disease. It seemed like an ideal place to start."
If all goes well, the company will quickly push into another cancer indication.
"Depending on the speed of recruitment in this first trial, we hope to finish the treatment phase by early 2009," Payne said. "During that time, we expect to file a second IDE with FDA for a separate cancer type."
Despite the fact that the country's most prominent nanotechnology spokesman has pointed to Nanospectra's AuroLase Therapy as the likeliest evidence of success from the burgeoning field, the company has maintained an extremely low profile since its inception in 2002.
It has been funded by Texas-based angel investors and was the recipient of an investment by the Texas Emerging Technology Fund in 2006.
"We're a small company with a focus on moving AuroLase through the clinic. Publicity doesn't help us," he said, adding that Nanospectra often gets calls from desperate cancer patients who don't understand that it might be several more years before the product is commercially available.
"We've been funded by high-net-worth individual angel investors," Payne said. "We try to maintain a fairly low overhead with an efficient cost structure." That funding didn't come easily, however, because there aren't a lot of venture capitalists in Texas.
But there will come a time when Nanospectra does need more exposure and additional funding.
"We'll do a Series B financing in the spring of 2009 to raise funds for a pivotal trial in head and neck cancer — depending of course on data from this trial — and for another pilot trial in a second cancer indication," Payne said.
Even then, Nanospectra would like to keep most of the business in-house rather than selling out or partnering with one of the big med-tech or biotech firms.
"Ideally, we'd prefer to find a distribution partner on the marketing side with a device sales force in one or more of our chosen markets," he said. "As we all know, partnering is more easily done once we have the positive clinical trial data."