Four-Year Survival and Durability Results of Brentuximab Vedotin in Combination with CHP in the Frontline Treatment of Patients with CD30-Expressing Peripheral T-Cell Lymphomas

Background

Peripheral T-cell lymphomas (PTCLs) encompass ~10-15% of aggressive non-Hodgkin lymphomas. Cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or variations thereof, are the most commonly used treatment regimens with complete remission (CR) rates ranging from 39-55% (Reimer 2009, d'Amore 2012). With the exception of low international prognostic index (IPI)-anaplastic lymphoma kinase (ALK)-positive ALCL, with 4-year progression-free survival (PFS) and overall survival (OS) ranging from 25-35% and 30-40%, respectively (Ellin 2014). We previously reported the results of this phase 1 trial that evaluated brentuximab vedotin (BV) administered in sequence with CHOP, or in combination with CHP (CHOP without vincristine) in treatment-naive patients (pts) with CD30-expressing PTCL (NCT01309789). The combination therapy (BV+CHP) showed safety and activity at standard doses, with an objective response rate (ORR) of 100% and complete response (CR) rate of 88% (Fanale 2014). The most common adverse events (AEs) experienced by pts were nausea and peripheral sensory neuropathy (69% each). Four-year durability data and updated results on peripheral neuropathy (PN) resolution from the BV+CHP combination treatment arm are presented herein.

Methods

Adults with CD30-expressing PTCL, including systemic ALCL (anaplastic large cell lymphoma, ALK-negative, or ALK-positive with IPI score ≥2) were eligible for this study. CD30 expression for non-ALCL pts was defined as ≥1% CD30 expression in malignant cells. Pts on the combination treatment arm received 1.8 mg/kg BV and standard-dose CHP q3wk for up to 6 cycles. Pts who achieved at least a partial response (PR) following treatment could receive continued BV 1.8 mg/kg q3wk as single-agent for up to 10 additional cycles. Antitumor response was assessed by the investigator according to the Revised Response Criteria for Malignant Lymphoma (Cheson 2007).

Results

Twenty-six previously untreated pts received BV+CHP. Disease diagnoses included systemic ALCL (n=19; including ALK-negative, n=16 and ALK-positive, n=3), PTCL-NOS (n=2), angioimmunoblastic T-cell lymphoma (AITL, n=2), adult T-cell leukemia/lymphoma (ATLL, n=2), and enteropathy-associated T-cell lymphoma (EATL, n=1). Twenty-one of the 26 pts who achieved remission with combination treatment continued on to receive single-agent BV. Overall, the 26 pts received a median of 13 cycles (range, 3 to 16) of BV.

After a median observation period of 52 months (range 4.6 to 58.3) from first dose, 18 pts remain on study. The estimated 4-year PFS and OS rates are 52% (95% CI: 31, 69) and 80% (95% CI: 59, 91), respectively. The median PFS has not been reached (95% CI: 12.3, -). To date, 15 of 19 ALCL (3/3 ALK-positive, 12/16 ALK-negative), and 6 of 7 non-ALCL pts were alive at last follow-up. Five pts (19%) received subsequent treatment with single-agent BV in long-term follow-up and 3 pts received stem cell transplants (1 autologous, 2 allogeneic) for relapsed disease. There were no pts who underwent a consolidative stem cell transplant.

Of the 26 pts treated with combination therapy, 19 (73%) experienced PN. Of these pts, 95% (18 of 19) experienced complete resolution (8 pts), or some resolution or improvement (defined as a decrease by at least 1 grade from worst grade, 10 pts). Of the pts who experienced improvement, 1 pt each improved from Grade 3 to a lowest Grade 2 and from Grade 3 to a lowest Grade 1, and 5 pts improved from Grade 2 to a lowest Grade 1. The median time to resolution of PN symptoms was 5.7 months. Eleven pts had ongoing neuropathy at last follow-up, of which, 9 pts had Grade 1 severity and 2 pts had Grade 2.

Conclusions

These 4-year durability results demonstrate that among pts with PTCL, initial therapy with BV in combination with CHP can induce long-term remissions with a tolerable safety profile. A phase 3 randomized trial comparing BV+CHP with CHOP for the frontline treatment of CD30-expressing PTCL is ongoing (NCT01777152).

Progression-free Survival

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