TSEB and Brentuximab for Treatment of Mycosis Fungoides & Sezary Syndrome

This study is a 2-cohort, open-label, phase 1B trial to evaluate the cutaneous toxicity, overall toxicity, and treatment response associated with administering concurrent low-dose TSEB and brentuximab vedotin in patients with mycosis fungoides or Sézary Syndrome. Duration of complete skin response, DOCB, and tumor response in lymph nodes and blood will also be evaluated. Additionally, skin-related QOL and neurotoxicity will be assessed. Patients will be enrolled in 1 of 2 cohorts based on disease stage. Cohort A will include patients with earlier stage disease (selected Stage IB in patients who have had one previous course of therapy) and Stages IIA through IIIA \[if N0-1\]). Cohort B will include patients with more advanced disease (Stage IIA through IIIA \[if N2-3\], Stage IIIB, Stage IVA, and transformed CTCL) who are candidates for low-dose TSEB and/or systemic therapy. A standard dose of brentuximab vedotin will be administered to all patients by intravenous infusion 3 weeks prior to initiation of low-dose TSEB and then every 3 weeks for a total of 3 cycles. Cohort A patients will complete brentuximab vedotin after 3 cycles; patients in Cohort B will continue brentuximab vedotin until disease progression or unacceptable toxicity, whichever occurs first. In the absence of progression or unacceptable toxicity, the patient may receive brentuximab vedotin for up to 2 years as a study participant. A total of 12 Gy TSEB (ie, low-dose TSEB) will be administered to both cohorts per standard protocol in 6 fractions (2 fractions per week) beginning 3 weeks after the first dose of brentuximab vedotin. The Modified Severity Weighted Assessment Tool (mSWAT) (16), completed by the investigator, will be used to determine skin involvement at baseline and skin response to treatment beginning after administration of the 3 doses of brentuximab vedotin and low-dose TSEB. Skindex-16, a patient-completed form that measures symptoms and perceptions of toxicity in patients with skin disease will be used to assess skin-related QOL. Additionally, Form NTX will be completed by patients in Cohort A to assess symptoms of CIPN which is a side effect of brentuximab vedotin. The sample size for this study will be a maximum of 15 patients for a total of 12 evaluable patients with no more than 6 patients in Cohort B. However, if the number of patients with severe toxicity exceeds the established acceptable incidence, accrual will end before reaching the sample size goal of 12 evaluable patients.