Effect of Immunotherapy (Keytruda) on MAC

Posted by juliea55 @juliea55, Apr 13 7:39am

I have cancer in addition to MAC. I have never undergone treatment for the MAC. Surprisingly I tolerated my chemo (carboplatin and abraxane) well, although my mucus production has increased slightly over the past year. Now I am facing immunotherapy and I am wondering if any of you with MAC have undergone immunotherapy, which really worries me. Did it worsen your MAC? Did anyone improve with immunotherapy? How long were you able to tolerate the treatments? Any responses would be appreciated.

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lvnl | @lvnl | Apr 13 11:24am

Hi, I'm sorry to hear what you are going through but glad you have been able to tolerate cancer treatment well so far. I'm sure others with more experience will respond here too. I'm not sure I can offer you good advice but I can let you know what your question prompted me to look into.
Your question got me to look up whether "immunotherapy" and "immune modulators" are the same thing. I am on Humira, an immune modulator for auto-immune conditions, which has successfully kept my Crohn's disease mostly in remission for 7+ years now, with no side effects.
There are surprisingly inconsistent definitions and distinctions between "immunotherapy" and "immune modulators" online. From what I can gather, "immunotherapy" usually refers to cancer treatments that leverage the body's own immune system to fight the cancer. "Immune modulators" refers to drugs that may crank the immune system up, OR tamp it down. Humira and other immune modulators used for autoimmune conditions tamp the immune system down to stop our immune systems from attacking our own bodies.
In my case, I had anticipated when I turned up positive for MAC that my doctors might want to stop the Humira, to stop the suppression of the immune system to allow it to fight the MAC. But no -- my Crohn's doctor is actually the doctor who got me in to the New York University Bronchiectasis/ Mac program. He shares many patients with them because inflammatory bowel disease (of which Crohn's is one type) is associated with bronchiectasis. They did NOT want me to stop the Humira since it has my Crohn's so well controlled. But they definitely wanted to treat me with antibiotics so my somewhat-suppressed immune system wouldn't allow the MAC to advance quickly.
This relationship between bronchiectasis, MAC and the immune system is not fully understood. There is some thinking that there may be an autoimmune, inflammatory component with bronchiectasis at least in some patients.
So this doesn't directly answer your question and again maybe others here have more direct experience. Most important is to consult your doctors and if possible get your cancer doctors to communicate with your MAC doctors on your treatment plan, because this is a complex interaction. This kind of forum can share invaluable information but I would not go on just the experience or input you hear about here. But given the immunomodulators for cancer strengthen and unleash your immune system to fight the cancer, there may be no counter-indication to antibiotics at all.
Best wishes on your next steps! Please keep us posted here.