# Brentuximab Vedotin in Advanced-Stage Mycosis Fungoides/Sézary Syndrome with Low CD30 Expression: Real-World Data from the German Cutaneous Lymphoma Network

## TL;DR

This study shows that the drug Brentuximab Vedotin can still help some patients with advanced skin lymphomas even when a key protein (CD30) is present in low amounts.

## Contribution

The study provides real-world evidence that Brentuximab Vedotin is effective in patients with low CD30 expression, a group previously understudied.

## Key findings

- 53.1% of patients with low CD30 expression responded to Brentuximab Vedotin treatment.
- Median progression-free survival was 4.0 months, and time to next treatment was 7.3 months.
- Results suggest the drug is a viable option for this patient group despite low CD30 levels.

## Abstract

Advanced-stage mycosis fungoides (MF) and Sézary syndrome (SS) are aggressive cutaneous T-cell lymphomas with limited treatment options and poor prognosis. Brentuximab vedotin (BV), an anti-CD30 antibody–drug conjugate, has shown high efficacy in patients with CD30 expression ≥ 10%, but data in low-CD30-expressing tumors are limited. This retrospective multicenter study evaluated 32 patients with advanced MF/SS and CD30 expression < 10% treated with standard-dose BV. All patients had received prior systemic therapies (median: 3). The overall response rate (ORR) was 53.1%, including 12.5% complete and 40.6% partial responses. Median progression-free survival (PFS) was 4.0 months, and median time to next treatment (TTNT) was 7.3 months. These results indicate that BV can induce meaningful responses even in tumors with low CD30 expression. Our findings support the use of BV as a therapeutic option in this population and highlight the need for further prospective studies to optimize patient selection and treatment outcomes.

Background/Objectives: Advanced-stage mycosis fungoides (MF) and Sézary syndrome (SS) are aggressive forms of cutaneous T-cell lymphoma (CTCL) for which treatment options are limited and prognosis is poor. Brentuximab vedotin (BV), an anti-CD30 antibody–drug conjugate, has demonstrated high response rates in patients with CD30 expression ≥ 10%. However, data on its efficacy in cases with low CD30 expression (<10%) remain scarce. Methods: This retrospective analysis evaluated the real-world efficacy of BV in patients with advanced-stage MF/SS and low CD30 expression. A retrospective analysis was conducted on 32 patients across 11 German CTCL expert centers. All patients had advanced-stage MF or SS with CD30 expression < 10% and received BV at the standard dose. Treatment response was assessed using EORTC-ISCL criteria. Results: All patients had received prior systemic therapies (median: 3) with 36% having undergone prior mono- or polychemotherapy. The study population included 30 MF (stage IIB) and two SS cases. The overall response rate (ORR) in this population was 53.1% (17/32). A complete response (CR) was achieved in 12.5% (4/32), a partial response (PR) was achieved in 40.6% (13/32), stable disease (SD) was seen in 18.8% (6/32), and progressive disease (PD) was seen in 28.1% (9/32). The median progression-free survival (PFS) was 4.0 months (arithmetic mean: 6.38; range: 0.5–15.5), and the median time to next treatment (TTNT) was 7.25 months (arithmetic mean: 7.30; range: 2.00–15.5). Conclusions: BV demonstrated encouraging activity in heavily pretreated advanced MF/SS with low CD30 expression, achieving an ORR comparable to that observed in patients with higher CD30 levels. While response rates were similar, PFS was shorter. These findings suggest that BV remains a potential therapeutic option in this patient population and merits further prospective investigation.