Evaluation of subcutaneous daratumumab injections in the ambulatory care setting.

INTRODUCTION: Subcutaneous daratumumab is non-inferior to intravenous daratumumab for the treatment of multiple myeloma and significantly reduced incidence of systemic reactions. However, manufacturer for subcutaneous daratumumab has not provided guidance regarding optimal methods for monitoring for hypersensitivity reactions following subcutaneous daratumumab administration. METHODS: A retrospective analysis was performed in two cohorts of patients who received at least two doses of subcutaneous daratumumab for the treatment of plasma cell disorders: patients with previous exposure to intravenous daratumumab (dara-exposed) and patients without history of intravenous daratumumab (dara-naïve). The primary outcome was incidence of systemic and injection-site reactions following first dose of subcutaneous daratumumab. Secondary analysis included time to systemic and injection-site reactions, grading of adverse reaction, and incidence of second systemic reaction. RESULTS: Thirty-one patients were dara-naïve and 49 patients were dara-exposed. Differences in incidence of systemic (dara-naïve: 9.7% vs dara-exposed: 6.1%, p = 0.67) and injection-site reactions (dara-naïve: 12.9% vs dara-exposed: 14.3%, p = 0.99) did not reach statistical significance. Difference in median time to systemic reaction (dara-naïve: 3 h vs dara-exposed: 12 h, p = 0.18) was clinically important but did not reach statistical significance. Median time to injection-site reactions (dara-naïve: 6 h vs dara-exposed: 24 h, p = 0.03) was shorter in the dara-naïve cohort. No clinically meaningful difference was observed for incidence of second systemic reaction. CONCLUSION: Most reactions were mild and did not require medical intervention. Following first subcutaneous daratumumab dose, monitoring for 3 h for dara-naïve patients and no monitoring time for dara-exposed patients for hypersensitivity reactions may be a safe and reasonable practice.

Impact of Polypharmacy Prior to Allogeneic Hematopoietic Stem Cell Transplantation in Older Adults.

Polypharmacy is common in older adults with cancer, but there is little evidence evaluating the impact of polypharmacy and other medication hazards on allogeneic hematopoietic cell transplantation (alloHCT) outcomes. A small number of prior studies have evaluated the impact of potentially inappropriate medication (PIM) use in the setting of alloHCT, with mixed results. We evaluated the effects of pre-alloHCT polypharmacy, PIM use, and drug-drug interactions (DDIs) on post-alloHCT outcomes, including overall survival (OS), progression-free survival (PFS), non-relapse mortality (NRM), hospital length of stay (LOS), number of non-hematologic grade ≥3 adverse events (AEs) within 100 days after alloHCT, and number of readmissions within the first 100 days after alloHCT. The study population was a single-center prospective cohort of 148 patients ≥ 50 years of age. Pre-alloHCT medication lists were retrospectively collected from the electronic medical record, including both scheduled and as-needed medications. PIMs were defined by a modified 2019 American Geriatrics Society Beers Criteria. DDIs were analyzed using Lexi-Interact. Polypharmacy was common in this population; the median number of medications was seven (range, 0 to 23). Fifty-two patients (35%) were prescribed nine or more medications, and 73 patients (49%) had at least one PIM prescribed. The median number of DDIs was three (range, 0 to 31), and the most common severity was major (48%). After adjusting for age and Hematopoietic Cell Transplant Comorbidity Index (HCTCI), both the number of all medications and number of scheduled medications were associated with inferior OS, with hazard ratios (HRs) of 1.07 (95% confidence interval [CI], 1.01 to 1.12; P = .02) and 1.08 (95% CI, 1.00 to 1.15; P = .04), respectively. Receipt of nine or more scheduled medications was associated with inferior OS (HR, 1.92; 95% CI, 1.11 to 3.32; P = .02). The number of PIMs was also significantly associated with OS (HR, 1.24; 95% CI, 1.00 to 1.54, P = .05). After adjusting for age, HCTCI, and total number of medications, a greater number of DDIs were significantly associated with longer hospital length of stay (difference, 0.74 days; 95% CI, 0.09 to 1.40, P = .03). In adjusted analyses, there were no significant polypharmacy-related predictors of NRM, LOS, or non-hematologic grade ≥3 AEs. These data demonstrate the utility of pre-alloHCT polypharmacy, PIM use, and DDIs as important prognostic factors and support routine pre-alloHCT medication review by physicians and pharmacists with a goal of appropriate de-prescribing where possible.