Pierce Brosnan and daughter Charlotte
Dave M. Benett/Getty
07/07/2013 at 01:30 PM EDT
During the last years of his daughter's life, Pierce Brosnan tried everything.
As Charlotte, 41, was becoming very ill from ovarian cancer, "Pierce was willing to pick up the phone and call anyone, go anywhere, take her anywhere, do anything for her at anytime,” says Lisa Paulsen, president of the Entertainment Industry Foundation and a longtime Brosnan family friend.
Despite his best efforts to get her into the latest clinical trials, Charlotte lost her three-year battle
with the disease on June 28.
"Charlotte fought her cancer with grace and humanity, courage and dignity. Our hearts are heavy with the loss of our beautiful dear girl," Brosnan told PEOPLE when news of her death broke.
Her mother, Cassandra Harris, also died
from the disease in 1991 while married to Brosnan, making Charlotte what is believed to be in the fourth generation in her family to get ovarian cancer. (When Harris was a teenager, her mother died of ovarian cancer, and it's also believed her grandmother died of the same disease.)
"There is an incredible cruelty in it all," Brosnan told PEOPLE four months after Cassandra's death. "Losing a person you shared everything with. ... It's overwhelming."
Adds Paulsen: "After Cassie passed away, Pierce became a fierce champion and ambassador to all things related to women's cancer research."
Friends say Brosnan, who found love again in Keely Shaye Smith (the two married
in 2001), hasn’t been fighting for cancer research in vain, despite his devastating personal losses.
"I told Pierce, 'Despite the fact that Charlotte didn't end up benefiting from long-term new ovarian cancer therapies, so many things that you have done have led to so many discoveries,'" says Paulsen. "He's a remarkable and loving father, and Charlotte was such a trooper."
For information on the Charlotte Brosnan Fund through EIF or to make a donation, click here