Depends whats the Chemo Tablet? That could be anything. Generally speaking MSI Low typed solid tumors haven't responded well to Keytruda. People with MSI-High typically do respond when in combination with FOLFOX or other chemo treatments. There are some studies taking place using Keytruda with other chemo drugs however that it is hoped will turn cold (MSI-Low) tumors to hot (MSI-High) type character, and make them respond better to attack by the immune system.
So if your wife is in a trial with a new combination of Keytruda with some other chemo drug, it would be of interest knowing what that chemo tablet actually is. There are a lot of new combinations being tried right now out there though few seem to be offered to folks with MSI-LOW form of colon cancer. Let us know a little bit more if you can about what exactly the drugs in use are, and someone might be better able to respond to you if they are undergoing the same or similar treatment. I believe there are a couple members that are trying Keytruda but with MSI-High tumors.
DW 53 dx Jun 2013
CT mets Liver Spleen lung. IVb CEA~110
Jul 2013 Sig Resct
8/13 FolFox,Avastin 12Tx mild sfx, Ongoing 5-FU Avastin every 3 wks.
CEA: good marker
7/7/14 CT Can't see the spleen Mets.
8/16/15 CEA Up, CT new abdominal mets. Iri, 5-FU, Avastin every 2 wks.
1/16 Iri, Erbitux and likely Avastin (Trial) CEA going >.
1/17 CEA up again dropped from Trial, Mets growth 4-6 mm in abdomen
5/2/17 Failed second trial, Hospitalized 15 days 5/11. Home Hospice 5/26, at peace 6/4/2017