Updated: Dec 19, 2019
David developed a rash over several parts of his body, which Dr. Brooks thinks was an allergic reaction to the Taxol IV chemo David has received the last two weeks. Between that and other side effects, such as extreme fatigue (which had been lessening after the radiation before David received Taxol), unsteadiness (hence, the recent fall), and hair loss, Dr. Brooks decided to give David a week off chemo.
In the meantime, Dr. Brooks will request approval from David's insurance company to use Keytruda (aka Pembrolizumab), which is an immunotherapy that has gotten a lot of positive press lately. You might recall that several months ago, David had some genetic testing done that showed he has a gene that makes it more likely that Keytruda might be effective for him. We are hoping that will be the case. We'd love for David to be one of the success stories you read about with immunotherapy.
Dr. Brooks said there should be no side effects but there might be complications later. Are you as puzzled by that statement as I was? Here's what Dr. Brooks said when I asked what that meant. He said there usually are no side effects during the drug administration, but because the drug revs up the immune system, there is a chance for the immune system to get too revved up and eventually cause auto-immune disease. So Dr. Brooks will need to monitor several things, such as David's thyroid levels, and David will need to report any changes he notices.
One positive thing is that Keytruda won't make David's neuropathy worse; the Taxol probably would have if David continued receiving that. Another positive is that David will receive it once every three weeks, rather than once a week as with the Taxol.
On a different note, since several of David's siblings have rightly wondered if they might have an increased risk for cancer, I asked Dr. Brooks if siblings should have any tests done. He said he will try to have germline genetic testing done on David. This website has a description of germline testing, how it differs from somatic genetic testing (which is what David had done before), and how each can be useful for determining treatments as well as determining whether family members may be at increased risk.