Hurvitz, Sara A.

Abstract Background: Follicular lymphoma is a B-cell malignancy in which tumor-immune system interactions have the potential to profoundly influence malignant cell growth. Cytotoxic T lymphocyte antigen 4 (CTLA-4) is a negative regulator of T cell activation that can serve to dampen anti-tumor immune responses. Administration of blocking anti-CTLA-4 monoclonal antibodies has been shown to improve host resistance to immunogenic tumors and amplify the anti-tumor effects of cancer vaccines in a variety of mouse tumor models. Recently, the anti-CTLA-4 antibody ipilimumab (MDX-010) has been shown to have significant clinical activity against melanoma, prostate, and ovarian cancers, with clinical responses associated with autoimmune events. Methods: We have therefore initiated a phase I/II trial of ipilimumab, a blocking fully human monoclonal antibody to CTLA-4, in patients with relapsed or refractory follicular lymphoma (grade 1 or 2). Enrollment is stratified into 2 cohorts, with half of patients required to be previously treated with a lymphoma vaccine (idiotype or other). It is hypothesized that previously vaccinated subjects are more likely to have anti-lymphoma T cells amenable to activation by an anti-CTLA-4 antibody. Study objectives include characterization of drug safety, immunologic activity and potential clinical efficacy. Treatment consists of MDX-010 at 3 mg/kg, then monthly at 1 mg/kg x 3, with plans to escalate to 3 mg/kg monthly x 4 if tolerated. Results: To date, 12 patients have been treated and accrual to the first dose level has been completed. All patients were previously treated and the median number of prior treatment regimens was 2 (range 1–4). Eight patients had previously received rituximab and 6 patients had received prior anti-idiotype vaccines. Nine patients have completed therapy with ipilimumab and 3 patients are still receiving treatment. Ipilimumab was generally well tolerated and the most common adverse events attributed to ipilimumab in the first 9 patients include diarrhea (grade 3–3 patients, grade 1–1 patient), abdominal pain (grade 2–4, grade 1–2), anorexia (grade 2-1, grade 1 – 2), fatigue (grade 2 -2, grade 1–3, and neutropenia (grade 3-1, grade 1– 2). Among 9 patients evaluable for clinical response, 1 previously vaccinated patient had partial regression of multiple abdominal nodes, ongoing at 10+ months. T cell proliferative responses to the recall antigens tetanus toxoid and keyhole limpet hemocycanin (in idiotype-vaccinated cases) were measured pre- and post-ipilimumab. In 3 of 5 cases tested, including the patient with a clinical response, T cell proliferation to KLH and/or tetanus was significantly increased (>2-fold) one month after initiation of ipilimumab, implying expansion and/or activation of the memory T cell pool. Conclusions: Blockade of CTLA-4 signaling using ipilimumab is well tolerated at the dose used thus far in this ongoing study and has anti-tumor activity in patients with follicular B-cell lymphoma. Further evaluation of the efficacy of ipilimumab at this and higher doses is therefore warranted.

100 Background: Combining BEV with CT significantly improved progression-free survival (primary endpoint) in the E2100, AVADO, and RIBBON-1 trials in the 1st-line setting and the RIBBON-2 trial in the 2nd-line setting. Primary efficacy and safety results from RIBBON-2 have been published; here we present final OS results. Methods: Eligible patients (pts) had MBC that had progressed on 1st-line CT without BEV. 2nd-line CT (taxane, gemcitabine, capecitabine, or vinorelbine) was chosen before 2:1 randomization to CT with either BEV (10 mg/kg q2w or 15 mg/kg q3w) or PL continued until progression. Stratification factors were 2nd-line CT, hormone receptor status, and time from MBC diagnosis to 1st progression. All pts could receive BEV at progression. The primary endpoint was PFS. Final analysis of OS, a secondary endpoint, in the intent-to-treat population was planned after 557 events and provided 80% power to detect a hazard ratio (HR) of 0.77 (median OS increased from 14.0 to 18.2 months) at α=0.04. Results: At the time of data cutoff (Oct. 31, 2011), 184 (82%) of 225 pts in the CT/PL arm and 376 (82%) of 459 pts in the CT/BEV arm had died. BEV was administered in subsequent treatment lines in 12% vs 6% of pts, respectively. There was no difference in OS between treatment arms: HR 1.013 (95% CI 0.845–1.215), log-rank p=0.8843. Median OS was 17.8 months with CT/PL vs 18.6 months with CT/BEV. The 1-year OS rates were 69% vs 71%, respectively. Subgroup analyses by CT cohort showed HRs ranging from 0.86 (95% CI 0.58–1.29) in the capecitabine cohort (n=144) to 1.44 (95% CI 0.82–2.53) in the vinorelbine cohort (n=76). HRs were close to 1 for the two largest CT cohorts (taxane and gemcitabine). Exploratory analysis in the subgroup of patients with triple-negative MBC showed a HR of 0.85 (95% CI 0.58–1.26). Updated safety results were similar to those previously reported from the primary analysis. There were fewer fatal adverse events in the CT/BEV arm (1.5%) than in the CT/PL arm (3.2%). Conclusions: Final OS results from RIBBON-2 reveal no difference between treatment arms. No new safety signals were observed.

Purpose This phase III study compared the efficacy and safety of bevacizumab combined with standard chemotherapy regimens versus chemotherapy alone as second-line treatment of patients with human epidermal growth factor receptor 2 (HER2) –negative metastatic breast cancer. Patients and Methods Patients were randomly assigned 2:1 to chemotherapy + bevacizumab or to chemotherapy + placebo. Before random assignment, investigators chose capecitabine, a taxane (paclitaxel, nab-paclitaxel, or docetaxel), gemcitabine, or vinorelbine. Dosing for bevacizumab or placebo was 15 mg/kg every 3 weeks or 10 mg/kg every 2 weeks, depending on chemotherapy regimen. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, PFS by chemotherapy cohort, objective response rate (ORR), duration of objective response, 1-year survival rate, and safety. Results RIBBON-2 enrolled 684 patients (225, chemotherapy + placebo; 459, chemotherapy + bevacizumab). The combination of bevacizumab with chemotherapy demonstrated a statistically significant benefit. Median PFS increased from 5.1 to 7.2 months (stratified hazard ratio for PFS, 0.78; 95% CI, 0.64 to 0.93; P = .0072). The 10% improvement in ORR between the placebo- and bevacizumab-containing arms (39.5% v 29.6%; P = .0193), although not statistically significant, was consistent with previous trials. There was no statistically significant difference in overall survival. The most common grade ≥ 3 adverse events (AEs) related to bevacizumab treatment were hypertension (9.0%) and proteinuria (3.1%). There was an increased number of AEs leading to study discontinuation in the chemotherapy + bevacizumab arm compared with the chemotherapy + placebo arm (13.3% v 7.2%). Conclusion The combination of bevacizumab with commonly used chemotherapies improved PFS in the second-line treatment of patients with HER2-negative metastatic breast cancer, with a safety profile comparable with that in prior phase III studies.

Abstract Background: Three prior Phase III trials (E2100, AVADO, and RIBBON-1) established the clinical benefit of adding bevacizumab (BV) to various chemotherapies (chemos) as first-line treatment for metastatic breast cancer (MBC). A previous Phase III study (AVF2119g) in patients with predominantly heavily pre-treated MBC, in which BV was added to capecitabine (Cape), resulted in a significant increase in objective response rate (ORR), but did not meet the primary endpoint for progression-free survival (PFS). The current study, RIBBON-2, was designed to evaluate the efficacy and safety of the addition of BV to chemotherapies used as second-line treatment for MBC.Methods: Patients were randomized in a 2:1 ratio to chemo+BV or chemo+placebo (PL). Key eligibility criteria included one prior cytotoxic treatment for MBC, ECOG performance status of 0 to 1, and HER2-negative or unknown status. Prior to randomization, investigators chose one of the following chemo agents: taxane (T; paclitaxel 90 mg/m2/wk for 3 of the 4 weeks; paclitaxel 175 mg/m2, nab-paclitaxel 260 mg/m2, docetaxel 75–100 mg/m2, all given q3wk), gemcitabine (G; 1250 mg/m2 on Days 1 and 8 q3wk), Cape (2000 mg/m2 Days 1–14 q3wk), or vinorelbine (V; 30 mg/m2/wk). BV or PL was administered at 10 mg/kg q2wk or 15 mg/kg q3wk, depending on the chemo regimen. The primary endpoint of the study was investigator-assessed PFS pooled across the chemo cohorts. Key secondary endpoints included overall survival (OS), PFS within individual chemo cohorts, ORR, and safety.Results: 684 patients (T, 304; G, 160; Cape, 144; and V, 76) at 211 sites in 19 countries were randomized between February 2006 and June 2008. Overall, the two study arms were balanced for patient characteristics at baseline. The study met its primary endpoint of PFS pooled across chemo cohorts and also demonstrated a 10% increase in ORR when BV was added to chemo. At the interim analysis for OS, the median durations were 18 mo for chemo+BV and 16.4 mo for chemo+PL (see table).Across all chemo cohorts the incidence of BV-related AEs was consistent with data from previous studies. Hypertension was the only BV-related AE consistently increased in the chemo+BV arm across all chemo cohorts.Conclusions: The addition of BV to chemotherapies used for second-line treatment of MBC led to a significant improvement in PFS. The AE profile of BV in the overall study population and across the chemotherapy cohorts was consistent with that previously observed. Additional analyses, including PFS for the individual chemo cohorts, will be presented. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 42.

Abstract Purpose: The growth of non–Hodgkin lymphomas can be influenced by tumor–immune system interactions. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative regulator of T-cell activation that serves to dampen antitumor immune responses. Blocking anti–CTLA-4 monoclonal antibodies improves host resistance to immunogenic tumors, and the anti–CTLA-4 antibody ipilimumab (MDX-010) has clinical activity against melanoma, prostate, and ovarian cancers. Experimental Design: We did a phase I trial of ipilimumab in patients with relapsed/refractory B-cell lymphoma to evaluate safety, immunologic activity, and potential clinical efficacy. Treatment consisted of ipilimumab at 3 mg/kg and then monthly at 1 mg/kg × 3 months (dose level 1), with subsequent escalation to 3 mg/kg monthly × 4 months (dose level 2). Results: Eighteen patients were treated, 12 at the lower dose level and 6 at the higher dose level. Ipilimumab was generally well tolerated, with common adverse events attributed to it, including diarrhea, headache, abdominal pain, anorexia, fatigue, neutropenia, and thrombocytopenia. Two patients had clinical responses; one patient with diffuse large B-cell lymphoma had an ongoing complete response (>31 months), and one with follicular lymphoma had a partial response lasting 19 months. In 5 of 16 cases tested (31%), T-cell proliferation to recall antigens was significantly increased (>2-fold) after ipilimumab therapy. Conclusions: Blockade of CTLA-4 signaling with the use of ipilimumab is well tolerated at the doses used and has antitumor activity in patients with B-cell lymphoma. Further evaluation of ipilimumab alone or in combination with other agents in B-cell lymphoma patients is therefore warranted. (Clin Cancer Res 2009;15(20):6446–53)