Is sleeping all day a bad sign?

My mom was diagnosed with stage 4 metastatic melanoma in April 2021. She has tried every treatment possible since then. In December 2023 a clinical trial almost killed her and she spent a month in the hospital. She regained strength after that but then she did immunotherapy & Tvec injections this spring and we found out those aren’t working. She’s also done a couple rounds of radiation this year. She’s supposed to start a new clinical trial this upcoming week that only 75 people in the US are getting. She’s recently started sleeping pretty much all day, when she’s awake she’s lucid and normal but is maybe only actually awake for 4-6 hours each day - is that a bad sign? To be sleeping all day?