Andres Forero-Torres

Brentuximab Vedotin (SGN-35) for Relapsed CD30-Positive Lymphomas

BACKGROUND Hodgkins lymphoma and anaplastic large-cell lymphoma are the two most common tumors expressing CD30. Previous attempts to target the CD30 antigen with monoclonal-based therapies have shown minimal activity. To enhance the antitumor activity of CD30-directed therapy, the antitubulin agent monomethyl auristatin E (MMAE) was attached to a CD30-specific monoclonal antibody by an enzyme-cleavable linker, producing the antibody-drug conjugate brentuximab vedotin (SGN-35). METHODS In this phase 1, open-label, multicenter dose-escalation study, we administered brentuximab vedotin (at a dose of 0.1 to 3.6 mg per kilogram of body weight) every 3 weeks to 45 patients with relapsed or refractory CD30-positive hematologic cancers, primarily Hodgkins lymphoma and anaplastic large-cell lymphoma. Patients had received a median of three previous chemotherapy regimens (range, one to seven), and 73% had undergone autologous stem-cell transplantation. RESULTS The maximum tolerated dose was 1.8 mg per kilogram, administered every 3 weeks. Objective responses, including 11 complete remissions, were observed in 17 patients. Of 12 patients who received the 1.8-mg-per-kilogram dose, 6 (50%) had an objective response. The median duration of response was at least 9.7 months. Tumor regression was observed in 36 of 42 patients who could be evaluated (86%). The most common adverse events were fatigue, pyrexia, diarrhea, nausea, neutropenia, and peripheral neuropathy. CONCLUSIONS Brentuximab vedotin induced durable objective responses and resulted in tumor regression for most patients with relapsed or refractory CD30-positive lymphomas in this phase 1 study. Treatment was associated primarily with grade 1 or 2 (mild-to-moderate) toxic effects. (Funded by Seattle Genetics; ClinicalTrials.gov number, NCT00430846.).

Results of a Pivotal Phase II Study of Brentuximab Vedotin for Patients With Relapsed or Refractory Hodgkin's Lymphoma

PURPOSE Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers monomethyl auristatin E, an antimicrotubule agent, into CD30-expressing cells. In phase I studies, brentuximab vedotin demonstrated significant activity with a favorable safety profile in patients with relapsed or refractory CD30-positive lymphomas. PATIENTS AND METHODS In this multinational, open-label, phase II study, the efficacy and safety of brentuximab vedotin were evaluated in patients with relapsed or refractory Hodgkins lymphoma (HL) after autologous stem-cell transplantation (auto-SCT). Patients had histologically documented CD30-positive HL by central pathology review. A total of 102 patients were treated with brentuximab vedotin 1.8 mg/kg by intravenous infusion every 3 weeks. In the absence of disease progression or prohibitive toxicity, patients received a maximum of 16 cycles. The primary end point was the overall objective response rate (ORR) determined by an independent radiology review facility. RESULTS The ORR was 75% with complete remission (CR) in 34% of patients. The median progression-free survival time for all patients was 5.6 months, and the median duration of response for those in CR was 20.5 months. After a median observation time of more than 1.5 years, 31 patients were alive and free of documented progressive disease. The most common treatment-related adverse events were peripheral sensory neuropathy, nausea, fatigue, neutropenia, and diarrhea. CONCLUSION The ADC brentuximab vedotin was associated with manageable toxicity and induced objective responses in 75% of patients with relapsed or refractory HL after auto-SCT. Durable CRs approaching 2 years were observed, supporting study in earlier lines of therapy.

Bendamustine in Patients With Rituximab-Refractory Indolent and Transformed Non-Hodgkin's Lymphoma: Results From a Phase II Multicenter, Single-Agent Study

PURPOSE Bendamustine hydrochloride is an alkylating agent with novel mechanisms of action. This phase II multicenter study evaluated the efficacy and toxicity of bendamustine in patients with B-cell non-Hodgkins lymphoma (NHL) refractory to rituximab. PATIENTS AND METHODS Patients received bendamustine 120 mg/m(2) intravenously on days 1 and 2 of each 21-day cycle. Outcomes included response, duration of response, progression-free survival, and safety. RESULTS Seventy-six patients, ages 38 to 84 years, with predominantly stage III/IV indolent (80%) or transformed (20%) disease were treated; 74 were assessable for response. Twenty-four (32%) were refractory to chemotherapy. Patients received a median of two prior unique regimens. An overall response rate of 77% (15% complete response, 19% unconfirmed complete response, and 43% partial) was observed. The median duration of response was 6.7 months (95% CI, 5.1 to 9.9 months), 9.0 months (95% CI, 5.8 to 16.7) for patients with indolent disease, and 2.3 months (95% CI, 1.7 to 5.1) for those with transformed disease. Thirty-six percent of these responses exceeded 1 year. The most frequent nonhematologic adverse events included nausea and vomiting, fatigue, constipation, anorexia, fever, cough, and diarrhea. Grade 3 or 4 reversible hematologic toxicities included neutropenia (54%), thrombocytopenia (25%), and anemia (12%). CONCLUSION Single-agent bendamustine produced durable objective responses with acceptable toxicity in heavily pretreated patients with rituximab-refractory, indolent NHL. These findings are promising and will serve as a benchmark for future clinical trials in this novel patient population.

TBCRC 001: Randomized Phase II Study of Cetuximab in Combination With Carboplatin in Stage IV Triple-Negative Breast Cancer

PURPOSE Epidermal growth factor receptor (EGFR) is a targetable receptor frequently overexpressed in basal-like breast cancer, which comprises most triple-negative breast cancers (TNBCs), the only subtype without established targeted therapy. PATIENTS AND METHODS In this randomized phase II trial, patients with metastatic TNBC received anti-EGFR antibody cetuximab (400 mg/m(2) load then 250 mg/m(2) per week intravenously [IV]) alone, with carboplatin (area under the curve of 2, once per week IV) added after progression or as concomitant therapy from the beginning. Response rate (RR) was the primary end point; others included time to progression (TTP), overall survival (OS), and toxicity. Embedded correlative studies included molecular subtyping on archival tissue. Fresh tumor tissue before and after 7 to 14 days of therapy was used for microarray analyses exploring EGFR pathway activity and inhibition. RESULTS In 102 patients with TNBC, RRs were 6% (two of 31) to cetuximab and 16% (four of 25) to cetuximab plus carboplatin after progression. RR to those treated from the beginning with cetuximab plus carboplatin was 17% (12 of 71); 31% of patients responded or had prolonged disease stabilization. The cetuximab plus carboplatin regimen was well tolerated, but both TTP and OS were short at 2.1 months (95% CI, 1.8 to 5.5 months) and 10.4 months (95% CI, 7.7 to 13.1 months), respectively. Of 73 patients with archival tissue for analysis, 74% had basal-like molecular subtype. Sixteen patients had tumor biopsies before and 1 week after therapy; genomic patterns of the EGFR pathway showed activation in 13 and inhibition by therapy in five. CONCLUSION Despite strong preclinical data, combination cetuximab plus carboplatin in metastatic TNBC produced responses in fewer than 20% of patients. EGFR pathway analysis showed that most TNBCs involved activation. However, cetuximab blocked expression of the EGFR pathway in only a minority, suggesting that most had alternate mechanisms for pathway activation.

A Phase II study of SGN‐30 (anti‐CD30 mAb) in Hodgkin lymphoma or systemic anaplastic large cell lymphoma

SGN‐30, a chimeric anti‐CD30 monoclonal antibody, has demonstrated potent preclinical antitumour activity in both Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL). We conducted an open‐label, Phase II study to determine the safety and objective response rate of SGN‐30 in 79 patients with refractory/recurrent HL (n = 38) or systemic ALCL (n = 41). Each course of SGN‐30 comprised 6 weekly intravenous infusions, followed by a 2‐week treatment‐free period. Patients had received a median of 3 (range 1–5) prior regimens of chemotherapy or systemic therapy. The initial 40 patients received 6 mg/kg weekly; the latter 39 patients received 12 mg/kg weekly. In the ALCL group, two patients achieved a complete response and five additional patients achieved a partial response, with response durations ranging from 27 to 1460+ d. No objective responses were observed in the HL group; however, 11 patients (29%) had stable disease (duration 62–242 days). Although adverse events were common, most were mild or moderate, and no specific pattern of adverse events was observed in either disease group. These results demonstrate that weekly administration of SGN‐30 is safe, with modest clinical activity in patients with ALCL.

Phase I Study of the Humanized Anti-CD40 Monoclonal Antibody Dacetuzumab in Refractory or Recurrent Non-Hodgkin's Lymphoma

PURPOSE To evaluate the safety, maximum-tolerated dose (MTD), pharmacokinetics, and antitumor activity of dacetuzumab in patients with refractory or recurrent B-cell non-Hodgkins lymphoma (NHL). PATIENTS AND METHODS In this open-label, dose-escalation phase I study, dacetuzumab was administered to six cohorts of adult patients. In the first cohort, patients received 2 mg/kg weekly for 4 weeks; in all other cohorts, an intrapatient dose-escalation schedule was used with increasing doses up to a maximum of 8 mg/kg. Patients with clinical benefit after one cycle of dacetuzumab were eligible for a second cycle. RESULTS In the 50 patients who received dacetuzumab, no dose dependence of adverse events (AEs) was observed. The most common AEs in >or= 20% of patients were fatigue, pyrexia, and headache; most were grade 1 or 2. Noninfectious inflammatory eye disorders occurred in 12% of patients. AEs grade >or= 3 occurred in 30% of patients and included disease progression, anemia, pleural effusion, and thrombocytopenia. Most laboratory abnormalities were grade 1 or 2; transient elevated hepatic aminotransferases occurred in 52% of patients. Two patients experienced dose-limiting toxicity: grade 3 conjunctivitis and transient vision loss in cohort (1), and grade 3 ALT elevation in cohort IV. The MTD of dacetuzumab was not established at the dose levels tested. Six objective responses were reported (one complete response, five partial responses). Tumor size decreased in approximately one third of patients. CONCLUSION Dacetuzumab monotherapy was well tolerated in patients with NHL in doses up to 8 mg/kg/wk. Preliminary response data are encouraging and support additional studies of dacetuzumab in this patient population.

A Phase I Weekly Dosing Study of Brentuximab Vedotin in Patients with Relapsed/Refractory CD30-Positive Hematologic Malignancies

Purpose: The antibody–drug conjugate (ADC) brentuximab vedotin comprises a CD30-directed antibody covalently attached to the potent antimicrotubule agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. This study explored the safety, maximum-tolerated dose (MTD), and activity of weekly dosing of brentuximab vedotin in patients with relapsed or refractory CD30-positive hematologic malignancies. Experimental Design: In this phase I dose-escalation study, brentuximab vedotin was administered intravenously on Days 1, 8, and 15, of each 28-day cycle at doses ranging from 0.4 to 1.4 mg/kg. Forty-four patients were enrolled: 38 with Hodgkin lymphoma, five with systemic anaplastic large cell lymphoma, and one with peripheral T-cell lymphoma not otherwise specified. Doses were escalated in increments of 0.2 mg/kg until dose-limiting toxicity (DLT) was observed. Patients were monitored for antitherapeutic antibodies and pharmacokinetic parameters. Antitumor assessments were carried out every two cycles. Results: The MTD was 1.2 mg/kg. The most common adverse events were peripheral sensory neuropathy, fatigue, nausea, diarrhea, arthralgia, and pyrexia; and the majority of events were mild to moderate in severity. Tumor regression occurred in 85% of patients and the overall objective response rate was 59% (n = 24), with 34% (n = 14) complete remissions. The median duration of response was not reached at a median follow-up of 45 weeks on study. Conclusions: Weekly administration of brentuximab vedotin resulted in tumor regression and durable remissions in patients with CD30-positive malignancies. This ADC was associated with manageable toxicity, including peripheral neuropathy. Further study in CD30-positive malignancies is warranted. Clin Cancer Res; 18(1); 248–55. ©2011 AACR.

Phase I Trial of Weekly Tigatuzumab, an Agonistic Humanized Monoclonal Antibody Targeting Death Receptor 5 (DR5)

BACKGROUND TRA-8 is a murine agonist monoclonal antibody to death receptor 5 (DR5), which is able to trigger apoptosis in DR5 positive human tumor cells without the aid of crosslinking. It has demonstrated cytotoxicity in vitro and in vivo antitumor efficacy to a wide range of solid tumors in murine xenograft models. Tigatuzumab is a humanized IgG1 monoclonal antibody derived from TRA-8. METHODS A phase I trial of tigatuzumab in patients with relapsed/refractory carcinomas (n = 16) or lymphoma (n = 1) was designed to determine the maximal tolerated dose (MTD), pharmacokinetics, immunogenicity, and safety. Three to six (3-6) patients were enrolled in successive escalating cohorts at doses ranging from 1 to 8 mg/kg weekly. RESULTS Seventeen (17) patients enrolled, 9 in the 1-, 2-, and 4-mg/kg dose cohorts (3 in each cohort) and 8 in the 8-mg/kg dose cohort. Tigatuzumab was well tolerated with no DLTs observed, and the MTD was not reached. There were no study-drug-related grade 3 or 4, renal, hepatic, or hematologic toxicities. Plasma half-life was 6-10 days, and no anti-tigatuzumab responses were detected. Seven (7) patients had stable disease, with the duration of response ranging from 81 to 798 days. CONCLUSIONS Tigatuzumab is well tolerated, and the MTD was not reached. The high number of patients with stable disease suggests antitumor activity.

A phase I study of dacetuzumab (SGN-40, a humanized anti-CD40 monoclonal antibody) in patients with chronic lymphocytic leukemia

Despite advances in therapy, chronic lymphocytic leukemia remains an incurable disease and novel, effective therapies are needed. In this open-label, dose-escalation, phase I study, dacetuzumab (IgG1 humanized monoclonal antibody) was administered to 12 adults, all of whom had received several prior systemic therapies (median, 4; range, 2–11). Intrapatient dose escalation (maximum weekly doses of 3–8 mg/kg) was used to diminish first-dose-related inflammatory symptoms. No dose-limiting toxicities or dose-dependent trends in adverse events (AEs) were observed. The most common AEs (in ≥2 patients) were fatigue, headache, anorexia, conjunctivitis, hyperhidrosis, and night sweats, all of which were mild or moderate. No deaths, serious AEs, or discontinuations due to AEs occurred. Although no patient achieved an objective response, five patients demonstrated stable disease after 1 cycle of therapy, with no discernable correlation between dacetuzumab dose and outcome. This modest single-agent activity may warrant further testing of dacetuzumab in combination with other chronic lymphocytic leukemia therapies.

Brentuximab Vedotin in the Front-Line Treatment of Patients With CD30+ Peripheral T-Cell Lymphomas: Results of a Phase I Study

PURPOSE Front-line treatment of peripheral T-cell lymphomas (PTCL) involves regimens such as cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) and results in a 5-year overall survival (OS) rate of less than 50%. This phase I open-label study evaluated the safety and activity of brentuximab vedotin administered sequentially with CHOP or in combination with CHP (CHOP without vincristine) as front-line treatment in patients with CD30(+) PTCL. PATIENTS AND METHODS Patients received sequential treatment (once every 3 weeks) with brentuximab vedotin 1.8 mg/kg (two cycles) followed by CHOP (six cycles) or brentuximab vedotin 1.8 mg/kg plus CHP (BV+CHP) for six cycles (once every 3 weeks). Responders received single-agent brentuximab vedotin for eight to 10 additional cycles (for a total of 16 cycles). The primary objective was assessment of safety; secondary end points included objective response rate, complete remission (CR) rate, progression-free survival rate (PFS), and OS. There were no prespecified comparisons of the two treatment approaches. RESULTS After sequential treatment, 11 (85%) of 13 patients achieved an objective response (CR rate, 62%; estimated 1-year PFS rate, 77%). Grade 3/4 adverse events occurred in eight (62%) of 13 patients. At the end of combination treatment, all patients (n = 26) achieved an objective response (CR rate, 88%; estimated 1-year PFS rate, 71%). All seven patients without anaplastic large-cell lymphoma achieved CR. Grade 3/4 adverse events (≥ 10%) in the combination-treatment group were febrile neutropenia (31%), neutropenia (23%), anemia (15%), and pulmonary embolism (12%). CONCLUSION Brentuximab vedotin, administered sequentially with CHOP or in combination with CHP, had a manageable safety profile and exhibited substantial antitumor activity in newly diagnosed patients with CD30(+) PTCL. A randomized phase III trial is under way, comparing BV+CHP with CHOP (clinical trial No. NCT01777152).