Lee Eric Newton of Princeton, New Jersey, still has a lot of living to do.

It’s all thanks to a clinical trial for a drug called atezolizumab, which Newton calls “liquid life.”

The 51-year-old single father has been living with bladder cancer since 2010.

When he was first diagnosed, doctors recommended removing his bladder, but he had other ideas. He chose surgery to remove the tumor without sacrificing his bladder.

Then he endured a series of treatments, but the aggressive cancer managed to spread.

Newton received chemotherapy on and off for two years. Eventually, negative side effects began to outweigh the benefits. Doctors weren’t sure his body could handle any more. He was running out of options.

When cancer was discovered in his brain, some doctors suggested it was time to put his affairs in order. But he wasn’t ready to leave his little girl just yet.

Read More: Get the Facts on Bladder Cancer »

A Clinical Trial Brings Survival

That’s when Newton contacted a bladder cancer specialist who suggested he look into clinical trials.

That led Newton to Dr. Mathew D. Galsky, an associate professor of medicine at the Icahn School of Medicine at Mount Sinai and director of genitourinary medical oncology at the Tisch Cancer Institute, both in New York.

Matching patients to clinical trials can be difficult, but Newton met the criteria.

“I got involved in the clinical trial because I wanted to live,” he told Healthline. “I also wanted to be part of something that may someday be used to save other lives.”

The drug atezolizumab is administered by intravenous drip, a process Newton says takes about 30 minutes.

He turned out to be one of a small number of patients in the trial who had a positive response to atezolizumab. He credits the treatment with significantly improving his quality of life.

Although his doctors won’t call it a cure, Newton’s condition is stable. Stable enough to be able to travel and enjoy life with his now 14-year-old daughter. He’s relishing every moment.

His treatment is ongoing. For Newton, as for most people on atezolizumab, side effects are minor, unlike the often debilitating side effects of chemotherapy.

“It’s miracle stuff,” said Newton.

Read More: Immune Systems Now a Major Focus of Cancer Treatment »

Using the Immune System to Attack Cancer

While he’s not calling it a miracle, Galsky is optimistic about the treatment.

“There have been many attempts to develop drugs without much success, so anything that works is a step forward,” he said in an interview with Healthline.

Galsky said the FDA hasn’t approved a new treatment for bladder cancer in more than 30 years. The cancer generally responds to chemotherapy, but it’s usually a short-lived response. Further options are limited.

Galsky explained that cancer can exploit the immune system. It clogs up regulation of certain proteins and tricks the immune system into ignoring the invading cells.

Atezolizumab is an immune checkpoint blockade. These drugs help the immune system recognize cancerous tumors as foreign and as something that should be attacked.

Preliminary results of the IMvigor210 study, the first large phase II study exploring immune checkpoint blockade in metastatic bladder cancer, were presented at the 2015 European Cancer Congress in September.

A year and a half after the trial began, researchers are still following patients who responded to the treatment.

“Unlike prior treatments like chemotherapy, when these drugs work, they work quite well,” said Galsky. “The responses are very durable, as you can tell from some patients who are continuing to receive these medicines a year and a half out. A medication that works and is tolerated so well is certainly reason for optimism and enthusiasm.”

The downside, said Galsky, is that these medicines only work this well in a small subset of patients. It’s not clear why that is. He hopes they can figure out how to turn nonresponsive patients into responders by using combination therapies or other approaches.

Galsky said many pharmaceutical companies are developing these types of drugs and they show promise for other types of cancers. This is the largest study so far for bladder cancer patients.

Read More: Extra Oxygen and Immunotherapy Slows Cancerous Tumor Growth »

A Watershed Moment

Another reason for Galsky’s optimism is that a breakthrough in drug development generally leads to intense interest in that type of cancer among investigators across the board.

“This is a watershed moment for bladder cancer,” said Galsky. “Many clinical trials are evaluating these medicines across the whole spectrum of bladder cancer.”

Ongoing studies are examining how to make the best use of these drugs. Galsky said one study is already looking at using these immune checkpoint drugs earlier in the course of the disease.

Clinical trials need patients who meet specific criteria. Lack of qualified participants hinders development.

“We can only make these advances if brave patients volunteer to participate,” said Galsky.

Navigating eligibility for clinical trials can be difficult for patients. He recommends starting with your oncologist. You can also search clinical trial databases at clinicaltrials.gov and bcan.org.

The American Cancer Society estimates there will be about 74,000 new cases of bladder cancer in the United States this year. About 16,000 people will die from the disease.

There are also more than 500,000 bladder cancer survivors. Newton is one of them.