Immix Biopharma (NSDQ:IMMX) has announced that the FDA has granted a rare pediatric disease designation related to the potential use of IMX-110 for rhabdomyosarcoma, a rare cancer affecting skeletal muscle. Roughly 400 to 500 cases of rhabdomyosarcoma occur each year in the U.S., according to cancer.org.  IMMX shares jumped 62.36% to $5.78 after the announcement. Immix…