Differential presentation of hypersensitivity reactions to carboplatin and oxaliplatin: Phenotypes, endotypes, and management with desensitization.

BACKGROUND: Drug hypersensitivity reactions (DHRs) to platinum-based drugs are heterogenous and restrict their access, and drug desensitization (DD) has provided a ground-breaking procedure for their re-introduction, although the response is heterogeneous. We aimed to identify the phenotypes, endotypes, and biomarkers of reactions to carboplatin and oxaliplatin and their response to DD. METHODS: Seventy-nine patients presenting with DHRs to oxaliplatin (N = 46) and carboplatin (N = 33) were evaluated at the Allergy Departments of two tertiary care hospitals in Spain. Patient symptoms, skin testing, biomarkers, and outcomes of 267 DDs were retrospectively analyzed. RESULTS: Oxaliplatin-reactive patients presented with type I (74%), cytokine release reaction (CRR) (11%), and mixed (Mx) (15%) phenotypes. In contrast, carboplatin reactive patients presented with predominantly type I (85%) and Mx (15%) but no CRRs. Out of 267 DDs, breakthrough reactions (BTRs) to oxaliplatin occurred twice as frequently as carboplatin (32% vs. 15%; p < .05). Phenotype switching from type I to another phenotype was observed in 46% of oxaliplatin DDs compared to 21% of carboplatin DDs. Tryptase was elevated in type I and Mx reactions, and IL-6 in CRR and Mx, indicating different mechanisms and endotypes. CONCLUSION: Carboplatin and oxaliplatin induced three different types of reactions with defined phenotypes and endotypes amendable to DD. Although most of the initial reactions for both were type I, oxaliplatin presented with unique CRR reactions. During DD, carboplatin reactive patients presented mostly type I BTR, while oxaliplatin-reactive patients frequently switched from type I to CRR, providing a critical difference and the need for personalized DD protocols.

Economic evaluation of obinutuzumab in combination with chlorambucil in first-line treatment of patients with chronic lymphocytic leukemia in Spain.

OBJECTIVE: To evaluate the cost-effectiveness of obinutuzumab in combination with chlorambucil (GClb) versus rituximab plus chlorambucil (RClb) in the treatment of adults with previously untreated chronic lymphocytic leukemia (CLL) and with comorbidities that make them unsuitable for full-dose fludarabine-based therapy, from the perspective of the Spanish National Health System. METHODS: A Markov model was developed with three mutually exclusive health states: progression-free survival (with or without treatment), progression, and death. Survival time for the two treatments was modeled based on the results of CLL11 clinical trial and external sources. Each health state was associated with a utility value and direct medical costs. The utilities were obtained from a utility elicitation study conducted in the UK. Costs and general background mortality data were obtained from published Spanish sources. Deterministic and probabilistic analyses were conducted, with a time frame of 20 years. The health outcomes were measured as life years (LYs) gained and quality-adjusted life years (QALYs) gained. Efficiency was measured as the cost per LY or per QALY gained of the most effective regimen. RESULTS: In the deterministic base case analysis, each patient treated with GClb resulted in 0.717 LYs gained and 0.673 QALYs gained versus RClb. The cost per LY and per QALY gained with GClb versus RClb was €23,314 and €24,838, respectively. The results proved stable in most of the univariate and probabilistic sensitivity analyses, with a probabilistic cost per QALY gained of €24,734 (95% confidence interval: €21,860-28,367). CONCLUSION: Using GClb to treat patients with previously untreated CLL for whom full-dose fludarabine-based therapy is unsuitable allows significant gains in terms of LYs and QALYs versus treatment with RClb. Treatment with GClb versus RClb can be regarded as efficient when considered the willingness to pay thresholds commonly used in Spain.