Kelley Mack, best known for her role as Addy on AMC’s hit series The Walking Dead, has died at the age of 33 following a courageous battle with diffuse midline glioma, a rare and aggressive cancer of the central nervous system.
A representative for Mack confirmed her passing to ABC News, while her family shared an emotional statement announcing she died on August 2, surrounded by her mother and aunt.
“It is with indelible sadness that we are announcing the passing of our dear Kelley,” her family wrote. “She was a bright, fervent light… Kelley has already come to many of her loved ones in the form of various butterflies. She will be missed by so many to depths that words cannot express.”
A Rare and Challenging Diagnosis
In January, Mack revealed on Instagram that she had been diagnosed with diffuse midline glioma — an extremely rare type of astrocytoma cancer. She explained that after experiencing persistent lower back pain and shooting pains in her legs and back, doctors confirmed the diagnosis.
Following biopsy surgery on her spinal cord, Mack lost the use of her right leg and most of her left leg, relying on a walker and wheelchair.
According to the National Cancer Institute, diffuse midline gliomas are a rare subtype of glial tumors, affecting about 3,940 people in the U.S. Symptoms can include double vision, trouble swallowing, loss of balance, and weakness on one or both sides of the body. Treatment may involve surgery, chemotherapy, radiation, or targeted medications. The five-year survival rate stands at just over 42%, depending on the tumor’s grade and the patient’s age.
Hollywood Career and Achievements
Mack’s breakout role came in season nine of The Walking Dead, where she portrayed Addy. She also appeared as Penelope Jacobs in season eight of Chicago Med, and starred as Alice in the horror film Broadcast Signal Intrusion.
Beyond acting, Mack was a producer, writer, and voiceover artist. She graduated from Chapman University in 2014 and spent the past decade building her career in Los Angeles. Born Kelley Klebenow in Cincinnati, Ohio, she grew up in Ohio, North Carolina, and Illinois. She was the eldest of three siblings, including her actor brother Parker Mack and sister Kathryn.
A Life Remembered
Her family announced that a “recognition and remembrance” will take place on August 16 in Glendale, Ohio, with a second celebration of life planned in Los Angeles at a later date.
Fans, friends, and co-stars have taken to social media to remember Mack’s talent, kindness, and strength. While her life was cut tragically short, her work and the impact she had on those around her will continue to be remembered.
