Gene editing of CCR5 in autologous CD4 T cells of persons infected with HIV.

BACKGROUND: CCR5 is the major coreceptor for human immunodeficiency virus (HIV). We investigated whether site-specific modification of the gene ("gene editing")--in this case, the infusion of autologous CD4 T cells in which the CCR5 gene was rendered permanently dysfunctional by a zinc-finger nuclease (ZFN)--is safe. METHODS: We enrolled 12 patients in an open-label, nonrandomized, uncontrolled study of a single dose of ZFN-modified autologous CD4 T cells. The patients had chronic aviremic HIV infection while they were receiving highly active antiretroviral therapy. Six of them underwent an interruption in antiretroviral treatment 4 weeks after the infusion of 10 billion autologous CD4 T cells, 11 to 28% of which were genetically modified with the ZFN. The primary outcome was safety as assessed by treatment-related adverse events. Secondary outcomes included measures of immune reconstitution and HIV resistance. RESULTS: One serious adverse event was associated with infusion of the ZFN-modified autologous CD4 T cells and was attributed to a transfusion reaction. The median CD4 T-cell count was 1517 per cubic millimeter at week 1, a significant increase from the preinfusion count of 448 per cubic millimeter (P<0.001). The median concentration of CCR5-modified CD4 T cells at 1 week was 250 cells per cubic millimeter. This constituted 8.8% of circulating peripheral-blood mononuclear cells and 13.9% of circulating CD4 T cells. Modified cells had an estimated mean half-life of 48 weeks. During treatment interruption and the resultant viremia, the decline in circulating CCR5-modified cells (-1.81 cells per day) was significantly less than the decline in unmodified cells (-7.25 cells per day) (P=0.02). HIV RNA became undetectable in one of four patients who could be evaluated. The blood level of HIV DNA decreased in most patients. CONCLUSIONS: CCR5-modified autologous CD4 T-cell infusions are safe within the limits of this study. (Funded by the National Institute of Allergy and Infectious Diseases and others; ClinicalTrials.gov number, NCT00842634.).

A phase II, randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of MDX-1100, a fully human anti-CXCL10 monoclonal antibody, in combination with methotrexate in patients with rheumatoid arthritis.

OBJECTIVE: CXCL10 (also known as interferon-γ-inducible 10-kd protein [IP-10]) is a chemokine that potentially plays a role in the immunopathogenesis of rheumatoid arthritis (RA). We undertook this phase II study to evaluate the efficacy and safety of MDX-1100, a fully human, anti-CXCL10 (anti-IP-10) monoclonal antibody, in RA patients whose disease responded inadequately to methotrexate (MTX). METHODS: Patients with active RA receiving stable doses of MTX (10-25 mg weekly) were randomized to receive intravenous doses of 10 mg/kg MDX-1100 (n = 35) or placebo (n = 35) every other week. The primary end point was the proportion of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) on day 85, and patients were followed up for safety to day 141. RESULTS: The ACR20 response rate was significantly higher among MDX-1100-treated patients than among placebo-treated patients (54% versus 17%; P = 0.0024). Statistically significant differences in the ACR20 response rate between treatments were observed starting on day 43 (P < 0.05). The ACR50 and ACR70 response rates on day 85 did not differ between the groups. Overall, 51.4% of MDX-1100-treated patients and 30.3% of placebo-treated patients experienced at least 1 adverse event (AE). No study drug-related serious AEs were reported. CONCLUSION: MDX-1100 was well tolerated and demonstrated clinical efficacy in RA patients whose disease responded inadequately to MTX. This is the first study to demonstrate clinical efficacy of a chemokine inhibitor in RA and supports the notion of a potential role of IP-10 in the immunopathogenesis of RA.

Extended dose ipilimumab with a peptide vaccine: immune correlates associated with clinical benefit in patients with resected high-risk stage IIIc/IV melanoma.

PURPOSE: To determine safety and feasibility of adjuvant ipilimumab following resection of high-risk melanoma and to identify surrogate markers for benefit. EXPERIMENTAL DESIGN: In this phase II trial, 75 patients with resected stage IIIc/IV melanoma received the CTLA-4 antibody ipilimumab every 6 to 8 weeks for 1 year. Eligible patients received further maintenance treatments. The first 25 patients received 3 mg/kg of ipilimumab, and an additional 50 patients received 10 mg/kg. HLA-A*0201+ patients received multipeptide immunizations in combination with ipilimumab. Leukapheresis was performed prior to and 6 months after initiation of treatment. RESULTS: Median overall and relapse-free survivals were not reached after a median follow-up of 29.5 months. Significant immune-related adverse events were observed in 28 of 75 patients and were positively associated with longer relapse-free survival. Antigen-specific T cell responses to vaccine were variable, and vaccine combination was not associated with additional benefit. No effects on T regulatory cells were observed. Higher changes in Th-17 inducible frequency were a surrogate marker of freedom from relapse (P = 0.047), and higher baseline C-reactive protein (CRP) levels were associated with freedom from relapse (P = 0.035). CONCLUSIONS: Adjuvant ipilimumab following resection of melanoma at high risk for relapse appeared to be associated with improved outcome compared to historical reports. Significant immune-related adverse events were generally reversible and appeared to be associated with improved relapse-free survival. Although vaccination failed to induce a consistent in vitro measurable response, a higher change in Th-17 inducible cells and higher baseline CRP levels were positively associated with freedom from relapse.

Phase I/II study of ipilimumab for patients with metastatic melanoma.

PURPOSE: The primary objective of this phase I/II study was to determine the safety and pharmacokinetic profile of either transfectoma- or a hybridoma-derived ipilimumab. Secondary objectives included determination of a maximum-tolerated dose and assessment of clinical activity. PATIENTS AND METHODS: Eighty-eight patients with unresectable stage III or IV melanoma with at least one measurable lesion were treated. Mean age was 59 years, with 65% male and 35% female patients, and 79% of patients had received prior systemic therapy. Single doses of ipilimumab up to 20 mg/kg (group A, single dose), multiple doses up to 5 mg/kg (group A, multiple dose), and multiple doses up to 10 mg/kg (group B) were administered. RESULTS: Single dosing up to 20 mg/kg of transfectoma antibody was well tolerated, as were multiple doses up to 10 mg/kg without a maximum-tolerated dose. In group B, dose-limiting toxicity was seen in six of 23 melanoma patients. Grade 3 or 4 immune-related adverse events (irAEs) were observed in 14% of patients (12 of 88 patients), and grade 1 or 2 irAEs were seen in an additional 58%. The half-life of ipilimumab was 359 hours. In group B, there was one partial response (23+ months), one complete response (21+ months), and seven patients with stable disease (SD), for a disease control rate of 39%. Two patients in group B with SD had slow, steady decline in tumor burden that was ongoing at 1 year of observation. CONCLUSION: Ipilimumab has activity in patients with metastatic melanoma. Late responses were observed in patients with prolonged SD.

Autoimmunity correlates with tumor regression in patients with metastatic melanoma treated with anti-cytotoxic T-lymphocyte antigen-4.

PURPOSE: Previously, we reported our experience treating 14 patients with metastatic melanoma using a fully human antibody to cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) in conjunction with peptide vaccination. We have now treated 56 patients to evaluate two different dose schedules of anti-CTLA-4 and to explore the relationship between autoimmunity and tumor regression. PATIENTS AND METHODS: A total of 56 patients with progressive stage IV melanoma were enrolled onto the study. All had Karnofsky performance status > or = 60% with no prior history of autoimmunity. Twenty-nine patients received 3 mg/kg anti-CTLA-4 every 3 weeks, whereas 27 received 3 mg/kg as their initial dose with subsequent doses reduced to 1 mg/kg every 3 weeks. In both cohorts patients received concomitant vaccination with two modified HLA-A*0201-restricted peptides from the gp100 melanoma-associated antigen, gp100:209-217(210M) and gp100:280-288(288V). RESULTS: Two patients achieved a complete response (ongoing at 30 and 31 months, respectively) and five patients achieved a partial response (durations of 4, 6, 25+, 26+, and 34+ months, respectively), for an overall objective response rate of 13%. Tumor regression was seen in lung, liver, brain, lymph nodes, and subcutaneous sites. Of 14 patients with grade 3/4 autoimmune toxicity, five (36%) experienced a clinical response compared with only two responses in the 42 patients (5%) with no autoimmune toxicity (P = .008). There were no significant differences in response rate or toxicity between the two dose schedules. CONCLUSION: Administration of anti-CTLA-4 monoclonal antibody plus peptide vaccination can cause durable objective responses, which correlate with the induction of autoimmunity, in patients with metastatic melanoma.