Effects of Body Mass Index on Hypertriglyceridemia Associated with Oral Bexarotene Therapy: A Post Hoc Analysis of an Open-Label Comparative Clinical Study of Combined Bexarotene and Phototherapy Versus Bexarotene Monotherapy for Japanese Patients with Cutaneous T-Cell Lymphoma.

Background: Bexarotene, which has been approved for use in Japan since 2016, is an effective drug for cutaneous T-cell lymphoma; however, careful management is imperative because of its adverse events. We previously demonstrated the severity of bexarotene-associated hypertriglyceridemia and the need for bexarotene dose reduction for patients with cutaneous T-cell lymphoma and high body mass index (BMI); however, high BMI does not affect the efficacy of combined bexarotene and phototherapy treatment.

Objective: This study aimed to verify the effects of BMI on hypertriglyceridemia associated with oral bexarotene therapy.

Methods: We conducted a post hoc analysis of data from a previous randomized, open-label clinical study that compared combined bexarotene-phototherapy treatment with bexarotene monotherapy for cutaneous T-cell lymphoma by dividing patients into two groups based on BMI (<23 kg/m² and ≥23 kg/m²).

Results: No statistically significant association was observed between patients with BMI ≥23 kg/m² and severe hypertriglyceridemia; however, there was a significant association between BMI ≥23 kg/m² and severe hypertriglyceridemia for patients who received bexarotene monotherapy, but not for those who received combined bexarotene-phototherapy treatment. The exact reasons for the discrepancies between the results of this thorough analysis and those of our past research are unclear. However, high BMI may be a risk factor for hypertriglyceridemia. Additional unidentified risk factors could also affect treatment outcomes.

Conclusion: High BMI is the primary reason for hypertriglyceridemia-associated bexarotene dose reduction; however, unexplored risk factors other than high BMI could exist.