Evaluation of Chemotherapy Induced Nausea and Vomiting for Patients Receiving Post-Transplant Cyclophosphamide for Matched Related and Unrelated Donor Stem Cell Transplant with Ondansetron Plus Rolapitant Antiemetic Prophylaxis.

Purpose Prevention of chemotherapy induced nausea and vomiting (CINV) is an integral aspect of hematopoietic stem cell transplant (HCT) due to the emetogenicity of the conditioning regimen. Post-transplant cyclophosphamide (PTCy) is a highly emetogenic agent, emerging as a graft versus host disease (GVHD) prophylactic regimen for matched related (MRD) and unrelated donors (MUD).  The purpose was to evaluate episodes of nausea, vomiting, and antiemetic breakthrough medication utilization when ondansetron plus rolapitant was given for CINV prophylaxis during PTCy administration following triplet or quadruplet CINV prophylaxis with the conditioning regimen. Methods This was a single center, retrospective review of patients from July 2017 to August 2019 undergoing MRD or MUD stem cell transplant.  Episodes of nausea and emesis were extracted by review of nursing flowsheets in the electronic medical record.  Additionally, medication records were reviewed for the administration of breakthrough antiemetics, including dronabinol, ondansetron, prochlorperazine, scopolamine, and trimethobenzamide. Patients were evaluated each day chemotherapy was administered (acute phase) plus an additional three days (delayed phase) after completion of the conditioning regimen and PTCy. Results The analysis included 33 patients who were predominantly male (66.6%) with median age of 58 years.  Thirty patients (90%) received their graft from a MUD.  Indications for HCT, as well as the conditioning regimens, are listed in Fig 1. Rates of documented episodes of nausea, vomiting, and breakthrough antiemetic utilization are listed in Table 1.  Breakthrough medications were utilized by 30 patients (90%). A total of 173 doses were administered with 68 doses (40%) given during the conditioning regimen and 105 doses (60%) during PTCy (Fig 2).  Ondansetron was the most commonly used antiemetic with 105 doses (61%) followed by prochlorperazine with 68 doses (39%). Conclusions PTCy is highly emetogenic GVHD prophylaxis regimen requiring utilization of breakthrough antiemetics despite prophylaxis with ondansetron plus rolapitant.  This evaluation demonstrates CINV may be present when PTCy is administered for MUD and MRD grafts, despite quadruplet or triplet antiemetic prophylaxis with the conditioning regimen.  PTCy warrants additional antiemetic prophylaxis to minimize the use of breakthrough antiemetics.  Additionally, nausea and vomiting were not well documented in the medical record limiting analysis of clinical episodes. Future studies are needed to identify strategies to improve CINV protection when utilizing PTCy for MUD and MRD HCT.