Data from several clinical trials of ADCETRIS to be presented at ASCO annual meeting

Seattle Genetics, Inc. (Nasdaq:SGEN) today announced that data from several clinical trials of ADCETRIS (brentuximab vedotin) will be presented at the 2012 American Society of Clinical Oncology (ASCO) Annual Meeting being held June 1-5, 2012 in Chicago, IL. Data demonstrate the activity and tolerability when patients are retreated with ADCETRIS, the activity and tolerability of ADCETRIS in CD30-positive non-Hodgkin lymphomas and CD30 expression from a screening protocol in non-lymphoma malignancies. ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30.    

"Our goal is for ADCETRIS to become the foundation of therapy for CD30-positive malignancies and, to that end, we are aggressively investing in its clinical development and broadly exploring CD30 expression across numerous cancer types," said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. "Our data presentations at ASCO highlight the potential for ADCETRIS and reinforce our development strategy to generate data that will support stepwise growth of ADCETRIS for patients with CD30-expressing malignancies."

Retreatment with brentuximab vedotin in CD30-positive hematologic malignancies: a phase II study (Abstract #8027)

In a phase II trial, patients who previously responded to treatment with ADCETRIS, then discontinued treatment and subsequently had disease progression or relapse were eligible for retreatment. Data were reported from 24 patients treated to date on the study, including 16 with Hodgkin lymphoma (HL) and eight with systemic anaplastic large cell lymphoma (sALCL). Patients had received a median of four prior systemic therapies, including ADCETRIS. Key findings include:

• Of 23 evaluable patients, 70 percent (16 of 23) achieved an objective response after retreatment with ADCETRIS, including nine complete remissions (CRs) and seven partial remissions (PRs).
• Median duration of retreatment objective response was 8.8 months.
• Among retreated HL patients, nine of 16 (56 percent) achieved an objective response. Among retreated sALCL patients, seven of eight (88 percent) achieved an objective response.
• The most common adverse events were peripheral neuropathy (46 percent), nausea (42 percent), fatigue (38 percent), diarrhea (33 percent) and fever (29 percent).
• The phase II retreatment trial is ongoing.

Details of the poster discussion presentation are as follows:

• Saturday, June 2; 8:00 a.m. to 1:00 p.m. Central Time (CT), with discussion from 12:00 p.m. to 1:00 p.m. CT
• Poster display in room E450b and discussion in room E354a
• First author: Dr. Nancy L. Bartlett, Washington University, Siteman Cancer Center, St. Louis, MO

Brentuximab vedotin for relapsed or refractory non-Hodgkin lymphoma: preliminary results from a phase II study (Abstract #8070)

In a phase II clinical trial, patients with relapsed or refractory CD30-positive non-Hodgkin lymphomas, including diffuse large B-cell lymphoma (DLBCL), peripheral T-cell lymphoma and other less common lymphoma subtypes were enrolled. The trial was designed to assess the antitumor activity, duration of response and safety profile of ADCETRIS in these patients. At the time of data analysis, 28 patients had been enrolled, including 18 with B-cell malignancies and ten with T-cell malignancies. Across all patients, the median number of prior systemic therapies was three. Key findings include:

• Of 14 patients evaluable for response, five patients (36 percent) achieved an objective response, including three CRs and two PRs.
• Four of seven DLBCL patients treated with ADCETRIS achieved an objective response, including two CRs and two PRs.
• Seventy-one percent of patients achieved tumor reduction.
• ADCETRIS treatment was generally well-tolerated, with the most common adverse events being fatigue (21 percent), abdominal pain (17 percent), nausea (17 percent), chills (13 percent), diarrhea (13 percent) and vomiting (13 percent).
• Enrollment is ongoing.

Details of the poster presentation are as follows:

• Monday, June 4; 1:15 p.m. to 5:15 p.m. CT
• Poster presentation in S Hall A2; poster board #35C
• First author: Dr. Ranjana Advani, Stanford University Medical Center, Stanford, CA

ADCETRIS is not approved for the treatment of the non-Hodgkin lymphoma subtypes described in this presentation.

CD30 expression in non-lymphomatous malignancies (Abstract #3069)

In a screening study, assessment of CD30 expression was performed in patients who had a non-lymphoma malignancy and were relapsed or refractory to previous therapy, or had no alternative curative treatment option available. Patients with CD30 expression were eligible for a companion phase II clinical trial. Per the screening protocol, patients were considered to be CD30-positive and eligible for the companion clinical trial if at least 10 percent of malignant cells were positive by immunohistochemistry or at least 20 percent of malignant cells were positive by flow cytometry. At the time of data analysis, a total of 1,637 patients had been screened. Key findings include:

• Thirty-eight patients (2 percent) and 17 different malignant diagnoses were CD30 positive per protocol.
• The most common malignancies with CD30 expression were mesothelioma (5 of 18 patients; 28 percent), melanoma (6 of 64 patients; 9 percent), triple negative breast cancer (4 of 71 patients; 6 percent) and ovarian carcinoma (9 of 173 patients; 5 percent).
• Assessment of CD30 expression under the screening protocol is ongoing with target enrollment of up to 3,000 patient tumor samples.
• A phase II companion treatment protocol is ongoing to characterize the antitumor activity of ADCETRIS in patients with CD30-positive non-lymphoma malignancies and to correlate expression with activity.

Details of the poster presentation are as follows:

• Monday, June 4; 8:00 a.m. to 12:00 p.m. CT
• S Hall A2; poster board #16C
• First author: Dr. Jeff P. Sharman, Willamette Valley Center Institute and Research Center, Eugene, OR

ADCETRIS is not approved for the treatment of any non-lymphoma malignancy.