There are many different immunotherapy drugs, and on the whole, they tend to cause hair thinning, or slower hair growth, rather than total hair loss (as seen in some chemotherapy drugs). Drugs used in breast cancer, for example, such as trastuzumab deruxtecan (Enhertu), trastuzumab emtansine (Kadcyla), abemaciclib, palbociclib and ribociclib, can cause hair thinning and hair loss. If a patient is also having hormone therapy, and/or chemotherapy as well, then the hair may be more affected.
It is difficult to predict to what degree side effects might affect each individual cancer patient. It may be that the hair texture may change, and hair may thin. A hair salon may be able to test patch an area of the scalp first, (as scalp skin sensitivity is likely to be more likely), and may advise on a semi permanent product. Other options would be more vegetable based hair dyes.
Your mum will need to ask her hospital team/hospital specialist nurse, about the side effects of the particular drugs she will be having. They will know, based on other patients' experiences.
