Cyclin dependent kinase (CDK)4/6 inhibitors have produced tremendous advances in the treatment of hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer through their targeting of hormone signals that stimulate the proliferation of cancer cells. Three CDK4/6 inhibitors have been FDA approved for the treatment of hormone receptor-positive, HER2-negative metastatic breast cancer: palbociclib (Ibrance®, Pfizer Inc.), ribociclib (Kisqali®, Novartis), and abemaciclib (Verzenio®, Eli Lilly and Company). Given the increasing use of these therapies, i3 Health surveyed 67 oncology nurses at the Oncology Nursing Society (ONS) 44th Annual Congress in Anaheim, California, in April 2019 in order to assess nurses' familiarity with CDK4/6 inhibitors and their confidence in managing related adverse events.
Of the nurses surveyed, only 1 respondent (1.5%) was highly familiar with abemaciclib. Twenty-seven respondents (40.3%) were not at all familiar with this medication, 24 (35.8%) were slightly familiar with it, and 15 (22.4%) were moderately familiar with it. Results were somewhat similar for ribociclib: only 3 respondents (4.5%) expressed a high degree of familiarity with this medication. Twenty-eight (41.8%) said that it was not at all familiar, 23 (34.3%) that it was slightly familiar, and 13 (19.4%) that it was moderately familiar. Respondents were somewhat more knowledgeable about palbociclib, with 8 (11.9%) saying that it was highly familiar, 14 (20.9%) that it was not familiar, 26 (38.9%) that it was slightly familiar, and 19 (28.4%) that it was moderately familiar.
"The survey results demonstrate that while oncology nurses may be aware of CDK4/6 inhibitors, four years since the first CDK4/6 inhibitor was approved by the FDA in 2015, there continues to be a significant knowledge gap across the profession," commented Mikel Ross, MSN, RN, AGPCNP-BC, OCN®, CBCN, nurse practitioner in the Outpatient Breast Medicine Service at Memorial Sloan Kettering Cancer Center. "Oncology nurses, who are at the frontline where prescription meets patient, play a key role in patient education, safety monitoring, and management of side effects. For oncology nurses to optimally fulfil these functions for patients receiving CDK4/6 inhibitors, the survey suggests that additional education and resources regarding the class of drugs, not to mention the subtle but critical differences between the three, is required."
Nurses' confidence levels in treating adverse events associated with CDK4/6 inhibitors varied according to the adverse event in question. A moderate number of respondents felt highly confident in handling nausea/vomiting (34.3%), neutropenia (31.3%), and infection (31.3%), with fewer respondents feeling highly confident in the management of diarrhea (25.4%), anemia (23.9%), leukopenia (22.4%), and thrombocytopenia (22.4%). Fewer still felt highly confident in managing elevated alanine aminotransferase (ALT)/aspartate aminotransferase (AST) (11.9%) and prolonged QTc interval (8.9%).
Of the nurses surveyed, 76.1% indicated that they would like to receive education on CDK4/6 inhibitor therapy to enhance their oncology nursing practice.
"By filling this gap, not only would oncology nurses be better prepared, but their patients would be empowered to gain maximal benefit from these vital medications," concluded Mr. Ross.