Newswise — At age 87, Roszell Mack Jr. goes into the office every day nine years after being diagnosed with metastatic lung cancer. A personal assistant at Mr. Brilliant Farm in Lexington, Kentucky, he helps organize and manage special events and performs other duties for the horse farm’s owner. He’s been able to keep working because he’s had a durable response to the immunotherapy pembrolizumab.

Five-year survival data for pembrolizumab patients like Mack with advanced non-small cell lung cancer were presented June 1 at the 2019 ASCO Annual Meeting, May 31-June 4, in Chicago. He is a participant in the KEYNOTE-001 study that compiled the data. The study results showed a marked improvement over 5-year survival rates in the pre-immunotherapy era, which averaged only 5.5%. Pembrolizumab increased the survival rate to 23.2% after five years in people with advanced non-small cell lung cancer who had not previously been treated with chemotherapy and to 15.5% in those who had been previously treated with chemotherapy. The KEYNOTE-001 is the longest follow-up  study to date of people with advanced non-small cell lung cancer treated with pembrolizumab.

Mack’s physician, Leora Horn, MD, Ingram Associate Professor of Cancer Research and clinical director of Thoracic Oncology at Vanderbilt-Ingram Cancer Center (VICC) is one of the study’s investigators. Mack has been treated with only clinical trial options since his diagnosis, Horn said.

“Mr. Mack’s participation in KEYNOTE-001 is an example of a patient having access to a drug that could potentially prolong their survival before the drug has U.S. Food and Drug Administration approval,” Horn said. “Immune checkpoint inhibitors, such as pembrolizumab, have become an important treatment option for patients with lung cancer and have been FDA approved since 2015. We have been able to offer these agents through clinical trials to our patients since 2008. The updated 5-year survival presented at ASCO demonstrates a step forward in improving survival for a subset of lung cancer patients who benefit from checkpoint inhibitor therapy.”

Pembrolizumab blocks a protein interaction called the PD-L1 pathway that allows cancer cells to hide from T cells, keeping the T-cells from attacking. It unleashes the immune system against tumors.

“I’m doing excellent, and I feel great,” Mack said, who began taking the immunotherapy through a clinical trial. “I go into the office every day and have a great quality of life.”

He became accustomed to hard work early in life. Mack had to leave Lexington, the college town where he grew up, to pursue his career goal of becoming a chemist because at that time the University of Kentucky wouldn’t admit African-American students and the historically black Kentucky State University didn’t have a chemistry program.He went to Indiana University, working weekends during the school year as a church custodian and laboring on tobacco farms each summer to help his parents cover the cost of an out-of-state education.

He graduated with a degree in chemistry, went to work for IBM for more than 30 years and completed a second degree in business from Pace University. After retiring from IBM, he became a personal assistant to Allen Paulson, founder of Gulfstream Aerospace, until the airline entrepreneur’s death in 2000 then moved back to Lexington. Paulson was a race horse owner and had in his stable, Cigar, who won $9.9 million in earnings. Cigar lived at the Kentucky Horse Park before dying in 2014 at the age of 24.

“I would always go and take Cigar a bag of carrots and a bag of peppermints,” said Mack, who wound up working for another horse farm owner at Mt. Brilliant Farm.

When he was diagnosed with advanced lung cancer, he made the decision to come to Vanderbilt for treatment. “I can’t say enough good things about Dr. Horn, who has been my doctor since I was diagnosed,” Mack said. “We talked it over about going on the research program for the immunotherapy. I made the right decision. I can tell you that.”