Outcomes by CD30 expression in patients with CTCL receiving brentuximab vedotin (BV) vs physician's choice (PC) in the Phase 3 ALCANZA study.

Abstract

7517 Background: The Phase 3 ALCANZA study showed significant, durable responses with CD30-directed antibody-drug conjugate BV vs PC of methotrexate (MTX) or bexarotene (Bex) for CD30-positive (CD30+) cutaneous T cell lymphoma (CTCL). Uniform CD30 expression is characteristic of primary cutaneous anaplastic large cell lymphoma (pcALCL), but is variable among other subtypes including mycosis fungoides (MF). We examined activity of BV and MTX / Bex by CD30 expression in pts treated on the ALCANZA study. Methods: Adults with previously treated CD30+ MF or pcALCL were enrolled. MF pts had ≥2 skin biopsies from separate lesions, pcALCL had ≥1. Patients were scored CD30+ if ≥1 biopsy had ≥10% CD30+ lymphoid cells using an investigational Ventana diagnostic test, centrally assessed by one pathologist. We compared the proportion of MF subgroup pts (n=50 per treatment arm) with objective response lasting ≥4 months (ORR4; ALCANZA primary endpoint) and PFS in pts with all biopsies ≥10% CD30+ (CD30min ≥10%) vs ≥1 biopsy <10% CD30+ (CD30min <10%). Pts were randomized 1:1 to BV 1.8 mg/kg IV, Q3W, or PC for up to 16 three-week cycles. Results: 125/184 (68%) MF and 44/47 (94%) pcALCL pts were screened and scored CD30+. High inter-lesional variability in CD30 expression was seen in MF pts; 55/125 CD30+ MF pts (44%) had ≥1 biopsy with low (<10%) or undetectable CD30. 100/125 CD30+ MF pts were eligible and enrolled. In the BV arm, ORR4 was higher in MF pts with CD30min ≥10% vs <10%; median PFS with BV was higher in the CD30min <10% group (Table). ORR4 with BV was greater than PC over all CD30 expression ranges (CD30min <5%, 38% vs 13%; CD30 ≥5–≤20%, 35% vs 10%; CD30 >20%, 76% vs 7%, respectively). Conclusions: Notable inter-patient or inter-lesional variability in CD30 expression was seen in MF pts. Highly superior ORR4 and PFS endpoints were seen with BV over PC regardless of CD30min expression level. Clinical trial information: NCT01578499. [Table: see text]