Medical Oncologist Dr. David Fajgenbaum Explains How He Overcame Castleman Disease

The opening address at this year's ASCO Congress, the world's leading cancer meeting, was given by a 35-year-old physician: medical oncologist Dr. David Fajgenbaum. What makes Dr. Fajgenbaum so special?

Dr. David Fajgenbaum, an assistant professor at the University of Pennsylvania's Parelman School of Medicine, is an American immunobiologist and author who has devoted his life to science. He is better known for his story and struggle after developing Castleman disease as a third-year medical student. This very rare and fatal disease causes organ failure when the immune system attacks the body for unknown reasons. David Fajgenbaum says that, after learning during weeks in intensive care that his disease had no treatment, he came close to death almost 5 times and chemotherapy saved his life. The story of this disease, which no one fully understood at the time, and the treatment David discovered for himself amazes everyone.

While on his high school football team, he learned that his mother had brain cancer (GBM). She died of the disease 15 months later. After promising her that he would become a doctor, fight diseases such as cancer, and help people, David launched a campaign called "Actively Moving Forward", in which bereaved students provided one another with emotional support. While studying at the University of Pennsylvania School of Medicine, he began to feel weak. In his third year, he went to the hospital to find out why he had severe abdominal pain and swelling in his neck, and was diagnosed with the very rare idiopathic multicentric Castleman disease. His doctor told him that his organs were about to fail and he needed immediate intensive care. A few days later, his condition worsened. A retinal hemorrhage blinded his left eye, an extra 32 liters of fluid accumulated in his body, and he needed constant blood transfusions to survive. Doctors thought David would die and had told his family to say goodbye.

David Fajgenbaum was engaged to Caitlin Fajgenbaum, and their wedding was to take place on 24 May 2014. David did not want to miss his wedding, so as soon as his family left his bedside, he took out his phone and began researching his disease. What he learned made him very anxious: the life expectancy of 80 percent of patients with this disease was no more than two years, there was not enough medical research in this field, and no drug had been developed to treat the disease.

Since arriving at the hospital, he had managed to survive with high doses of chemotherapy. To make it to his wedding, he received an intensive chemotherapy regimen combining 7 different chemotherapy drugs. These treatments were very hard on David, but they also kept him alive. He had now realized that finding a solution would require his own efforts. He began running blood tests and conducting research in the laboratory.

For unknown reasons, his immune system was attacking healthy organs. Signaling pathways need to be active for the immune system to attack. There are 17 different signaling pathways, and one or all of them might have been active. While examining lymph node tissue to find out which pathway was active, he discovered that the mTOR signaling pathway was overactive. He hoped that shutting down these pathways would restore his immune system, and he needed an mTOR inhibitor to do so. An mTOR inhibitor drug was available, but it had never been used to treat Castleman disease. In fact, this immunosuppressant drug, called sirolimus and used for kidney transplantation, had received FDA approval in 1999. David knew there was no guarantee it would work for Castleman disease, but taking this drug saved his life.

In September 2019, David Fajgenbaum wrote a book called “Chasing My Cure” about this hopeful story. Having come close to death 5 times, survived each time with chemotherapy, and never lost hope, David says: “Try to find humor amid all of life's difficulties, and do not let go of the things you hope for. Sirolimus, which no one had thought of, was actually available in the pharmacy I walked past every day. Sometimes the solutions to the hardest problems can be right in front of you.”

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