Seattle Genetics Inc. (SGEN) summarized ADCETRIS (brentuximab vedotin) and CD30 expression data in non-Hodgkin lymphomas and other malignancies from multiple presentations at the 54th American Society of Hematology or ASH Annual Meeting and Exposition being held December 8-11, 2012 in Atlanta, GA.
Highlights include encouraging interim data from a phase II clinical trial of ADCETRIS in non-Hodgkin lymphoma and long-term follow up from a pivotal clinical trial of ADCETRIS in relapsed or refractory systemic anaplastic large cell lymphoma (sALCL). In addition, investigators presented data describing the expression of CD30 in DLBCL and case studies on ADCETRIS in patients with systemic mastocytosis. ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30.
In an ongoing phase II clinical trial, patients with relapsed or refractory CD30-positive non-Hodgkin lymphomas have been enrolled, including DLBCL and several other non-Hodgkin lymphoma subtypes. The trial is designed to assess the antitumor activity, duration of response and safety profile of ADCETRIS in these patients. At the time of data analysis, 73 patients had been enrolled, including 44 with B-cell lymphoma and 29 with T-cell lymphoma. The median number of prior systemic therapies in both lymphoma classifications was two.
Key findings include:Of 64 patients evaluable for response, 22 patients (34 percent) achieved an objective response, including 12 complete remissions and ten partial remissions. In B-cell lymphoma subtypes, 14 of 42 evaluable patients (33 percent) achieved an objective response, including 11 of 25 DLBCL patients (44 percent).
In T-cell lymphoma subtypes, eight of 22 evaluable patients (36 percent) achieved an objective response, including five of ten angioimmunoblastic T-cell lymphoma patients (50 percent). The most common treatment-emergent adverse events of any grade were fatigue (32 percent), neutropenia (26 percent), nausea (25 percent), diarrhea (23 percent) and fever (22 percent).
A pivotal, single-arm clinical trial was conducted in 58 relapsed or refractory sALCL patients to assess efficacy and safety of single-agent ADCETRIS. In addition, the trial was designed to determine duration of response, progression-free survival and overall survival. Enrolled patients had received a median of two prior chemotherapy regimens.
Data highlights from long-term patient follow up in the pivotal trial were Median duration of response has not yet been reached for the 34 patients (59 percent) who achieved a complete remission on study, and 18 patients (53 percent) remained in continued complete remission at the time of data analysis. Estimated overall survival rate of patients at two years from initiation of ADCETRIS treatment was 63 percent.
In two investigator-led abstracts, data described the outcome of research into CD30 expression in DLBCL patient samples. In one presentation, data indicated that 24.7 percent of DLBCL cases expressed CD30 by immunohistochemistry (95 of 385 samples). In a separate analysis, 23 percent of DLBCL cases expressed CD30 by immunohistochemistry (34 of 148 samples). Both investigators concluded that clinical evaluation of ADCETRIS in DLBCL is warranted.
by RTT Staff Writer
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