Dressed to Kill (Cancer)

“Raise your hand if you haven’t been touched by cancer,” says Mylisa Parette to a roomful of strangers.

Parette, the research manager for Keystone Nano, has occasional opportunities to present her company’s technologies to business groups and wants to emphasize the scope of the problem that still confronts society. “It’s easier to see the effects of cancer when nobody raises their hand,” she says. Despite 40 years of the War on Cancer, one in two men and one in three women will be diagnosed with the disease at some point in their lifetime.

Parette and her Keystone Nano colleagues are working on a new approach to cancer treatment. The company was formed from the collaboration of two Penn State faculty members who realized that the nanoparticle research that the one was undertaking could be used to solve the drug delivery problems that the other was facing.

Mark Kester, a pharmacologist at Penn State College of Medicine in Hershey, was working with a new drug that showed real promise as a cancer therapy but that could be dangerous if injected directly into the bloodstream. Jim Adair, a materials scientist in University Park, was creating nontoxic nanoparticles that could enclose drugs that might normally be toxic or hydrophobic and were small enough to be taken up by cells.

The two combined their efforts and, licensing the resulting technology from Penn State, they joined with entrepreneur Jeff Davidson, founder of the Biotechnology Institute and the Pennsylvania Biotechnology Association, to form Keystone Nano. The new company’s first hire was Parette, whose job is to translate the lab-scale technology into something that can be ramped up to an industrial scale, and to prepare that technology for FDA approval leading to clinical trials.

Davidson, Parette, and KN’s research team work out of the Zetachron building, a long, one-story science incubator a mile from Penn State’s University Park campus. Operated by the Centre County Industrial Development Corporation, the building was originally the home of the successful Penn State spin-out company that gave it its name. A second Keystone Nano lab was recently opened in the Hershey Center for Applied Research, a biotech incubator adjacent to Penn State College of Medicine.

“Our excitement is that we think our technology has shown efficacy in a whole range of animal models,” Davidson, Keystone CEO, remarks during a recent meeting in the shared conference room at Zetachron. “We understand the method of action, the active ingredient. We think it has every chance of being useful in treating disease. Our question is, how do we push this forward from where we are today to determining, one way or another, that it really does work?”

Two approaches to drug delivery

Keystone Nano is pioneering two approaches to cancer therapy, both of which rely on advances in nanotechnology to infiltrate tumors and deliver a therapeutic agent. The approach nearest to clinical trials is a ceramide nanoliposome, or what Davidson calls a “nano fat ball around an active ingredient.” Kester, in whose lab the approach was developed, thinks of it as a basketball with a thick bilayer coating that contains 30 percent active ceramide and a hollow interior that can hold another cancer drug.

Kester is an expert on ceramide, a naturally occurring lipid, or fat molecule, that is involved with apoptosis, a type of programmed cell death. Part of the reason that cancer tumors are able to survive the body’s defenses, not to mention chemotherapy and radiation, he explains, is that the cancer can suppress ceramide activity in the tumor. The combination of a proven cancer drug, such as sorafenib, delivered in conjunction with ceramide could be a powerful approach to attacking drug-resistant tumors.

The second approach is Adair’s nanoparticles, called NanoJackets, because, Kester points out with a laugh, they are “dressed to kill.” Made from calcium phosphosilicate, a non-toxic material that is essentially the same biomaterial as teeth and bones, NanoJackets will encapsulate a variety of active pharmaceutical ingredients. They show promise both as powerful imaging agents for detecting early stage tumors, and as effective treatment for human breast cancer in animal models.

Both approaches are based on the ability to deliver toxic drugs directly to the site of a cancer tumor without the familiar off-target toxicities that plague most current cancer therapies, leading to nausea, hair loss, nerve damage, and sometimes even death. “Both of our technologies are based on non-toxic materials,” Parette emphasizes. “That gives us a significant advantage in a clinical setting.”

The struggles of a startup

There’s a good reason the transition from lab bench to production line is labeled the Valley of Death—it’s the place where most ideas go to die. This is even more the case for any technology meant to be used in the body. Big pharmaceutical companies claim to spend on average $1.25 billion on developing a new therapeutic. Davidson, the CEO whose main job is to try to keep the company above water financially, would be happy with an amount several zeros less than that.

“The problem is that most pharmaceutical companies want to get involved after the therapy has been proven safe and effective in humans,” Davidson remarks.

To keep their research moving forward, the Keystone team has relied on federal Small Business Innovation Research and other grants, and on contract work for pharmaceutical and materials companies who want to reformulate their products in nano packages. The contract work, Davidson says, has helped them keep technical staff employed and advanced their knowledge of how to scale up their own products.

Keystone Nano is now gearing up for a Phase I clinical trial, which the company hopes will begin in 2013. Before that can happen Keystone must finish preclinical testing and assemble an Investigation New Drug (IND) package for the ceramide nanoliposome for federal regulatory approval.

“In the preclinical stage there are always going to be things you run into,” says Parette. “So it’s hard to pinpoint the exact time we will be ready to go to the FDA. It’s a combination of factors that include a novel drug, ceramide, that hasn't been used in this way before, plus a different delivery technology, the nanoliposomes.”

Getting FDA approval involves collecting data from animal studies to demonstrate efficacy, safety and an absence of off-target toxicity. In addition, the IND package has a chemistry and manufacturing control section that requires Keystone to provide details of its manufacturing process. All in all, for a small company with only a handful of employees involved in developing new methods to measure novel compounds at the molecular level, these are formidable hurdles to overcome.

“Fortunately,” Davidson says, “Jim (Adair) is very helpful in identifying and helping us think about nanoparticle characteristics, transformations, purification, and analysis. And Mark (Kester) is very helpful in thinking about what tests you have to run to sort out efficacy and safety.”

Attacking liver cancer

The Hershey Center for Applied Research is within a long stone’s throw of the Hershey Medical Center and College of Medicine campus. Along with a number of startup biotech companies, the center houses the offices of the Penn State Department of Pharmacology. Mark Kester’s faculty office is on the third floor behind a door with a poster of his native Bronx, a heritage still evident in his speech patterns and his to-the-point style.

“Ceramide is an agent that kills only cancer cells in the doses we’re using,” Kester says. “Most therapeutics kill proliferating cells, which include hair follicles, white blood cells, and the gut lining. They can kill all the cancer, but kill the patient too. One problem with ceramide is that you’ve got a great cancer killer, but you can’t deliver it. In the blood, it would just turn into something resembling a salad dressing.”

But by encapsulating the ceramide in a tiny, water soluble globule of fat, they can solve the delivery problem. Liposome delivery is a time-tested method. The ceramide nanoliposomes are 70-80 nanometers in diameter with a polyethylene glycol coating that hides them from macrophages, the body’s police. They can also be tagged on the surface with small antibodies that only lock onto cancer cells.

“The problem with nanoliposomes is they can be made in small quantities, but they are hard to scale up to preclinical and clinical quantities,” Kester says. “We needed Keystone Nano to solve this, which they’ve done. Keystone is also leading the preclinical testing initiatives and funding the research, and holding discussions with prospective partners. Once it goes to clinical trials, Jim (Adair) and I will not be involved in the clinical testing.”

The initial target is liver cancer, a disease that is widespread in Asia and growing quickly in the U.S. Nearly 700,000 people are diagnosed with the disease annually and most patients succumb to the disease within a year of being diagnosed. The current best therapy, called sorafinib, provides only six to nine extra weeks of life. “We can do better,” Kester says.

In at least 10 peer-reviewed papers, he and his colleagues have shown that ceramide nanoliposomes are capable of killing liver and breast cancer, melanoma, and certain types of leukemia.

A Phase I clinical trial, Davidson explains, is typically geared toward safety and determining dosage of the active agent, and in this case will involve 20 to 25 patients. Phase II deals with efficacy and Phase III looks more critically at a larger patient population.

At Hershey Medical Center, where the trials may take place, there are in the neighborhood of 90 patients receiving treatment for liver cancer at any given time, so finding 20 who would be candidates for the trial should not pose a problem, Davidson believes. “They would have to agree to participate and receive an injection. However, the outcome for those patients is near certain death, so they are quite willing to try something, if not for themselves, then for others.”

NanoJackets—the next technology

Meanwhile, the nanoparticles called NanoJackets, created in Adair&rquo;s lab several years ago, have been undergoing extensive refinement and scale-up at Keystone. Davidson estimates they are about 18 months away from a clinical trial, but a recent $1 million grant from the Pennsylvania Department of Health through its Commonwealth Universal Research Enhancement (CURE) program should help speed the process.

Adair’s particles range from 5 to 50 nanometers in diameter and come in concentrations of a million billion particles per milliliter. One of their remarkable qualities is their ability to increase the longevity and enhance the luminosity of fluorescent dyes.

In a conference room at the Hershey Center for Applied Research, Kester shows off this ability, which could be extremely useful for tumor imaging. Small tubes of fluorescent dyes encapsulated in nanoparticles created over five years ago still glow green, blue, and orange under an infrared light.

In one scenario, NanoJackets could be loaded with a dye that glows brightly enough to light up very small tumors at significantly greater tissue depth than other fluorescent probes, and at the same time deliver a cancer drug. Combining the two effects makes it possible to track the particles into the tumor, release the active agent, and then watch to see if the drug is shrinking the tumor. Adair and Kester call it theranostics, therapeutics and diagnostics rolled into one.

In passive targeting, nanoparticles circulate in the bloodstream until they find their way into tumors through the poorly formed blood vessels that fast-growing tumors develop. Once within the tumors, the particles can further diffuse to deliver drugs to nearby cancer cells, Parette explains.

Keystone also uses a variety of methods to actively bind to cancer-specific cellular receptors, she adds. By attaching some kind of ligand, or binding molecule, to the surface of their particles, they can go after cells in leukemia and other non-solid tumors.

The future of nanomedicine

In the next few years, Parette says, cheap genetic sequencing should allow treatments to be devised for individualized cancer care. One promising technology involves siRNA—an artificial snippet of RNA that can knock out the gene activity in cancer cells. The major issue to date has been how to deliver these short interfering RNA sequences to the proper location in enough quantity to shut down the cancer cells. NanoJackets could be one of those methods.

“The interesting part,” says Parette, “is that current drugs are untargeted—there is no selectivity. On the other hand, we’ve got multiple layers of targeting. We’ve got nano, which takes advantage of enhanced permeability and retention. Or we can actively target using ligands or antibodies. Then it turns out that the active ingredients we are working with are selective in and of themselves: Both the ceramide nanoliposomes and the siRNA NanoJackets are active in cancer cells but not in noncancerous cells.”

“The future of medicine is small,” Kester says with no evident irony. “Really small. Every pharmaceutical company is trying to figure out how to deliver molecular-based therapies.”

By as early as 2015, he predicts, a patient coming into a hospital for cancer treatment will have a swab done to find out why he or she has cancer. Then the oncologist will design a drug that goes after only that particular mutation. And Keystone Nano will have a technology to deliver the drug directly into the cancer cell.

Jeff Davidson, CEO of Keystone Nano can be contacted at jdavidson@keystonenano.com and Mylisa Parette, Ph.D., research manager, can be contacted at mparette@keystonenano.com. Jim Adair, Ph.D., is Keystone Nano's chief science officer and professor of materials science and engineering and of bioengineering at Penn State University. He can be contacted at jha3@psu.edu. Mark Kester, Ph.D., is Keystone Nano's chief medical officer and the Thomas Passananti Professor of Pharmacology and director of the Penn State Center for NanoMedicine and Materials in the College of Medicine. He can be contacted at mkester@psu.edu.

Keystone Nano has received support from the Nanotechnology Institute of Pennsylvania, the National Cancer Institute, the Pennsylvania NanoMaterials Commercialization Center, Ben Franklin Technology Partners, and Penn State.

A version of this article appeared in the Spring 2012 issue of Penn State Focus on Materials.

Last Updated November 11, 2013