What to expect ? Anyone tried Faspro?

My mother was just recently diagnosed with advanced MM. She is 77 yrs old. She was started on steroids and short developed a MM tumor in her eye and can’t see in the left eye. She was recently started on Faspro(daratumumab). Now her condition seems worse. She’s very weak, unstable on her feet, lethargic, looks skinnier, intermittent confusion, not eating, and increased pain. I know she may be more tired than usual but it seems like the injections made her worse. I’m hoping she will pull through. She only had one injection and scheduled this week for another and she is suppose to start radiation, but the way she is looking, I don’t think she can. I’m scared. Any recommendations? Is this usual? Anyone have experience with faspro?