Phase III randomized study of ipilimumab (IPI) plus dacarbazine (DTIC) versus DTIC alone as first-line treatment in patients with unresectable stage III or IV melanoma

LBA5

Background: IPI monotherapy (3mg/kg) improved overall survival (OS) in a phase III study of previously treated, unresectable or metastatic melanoma. Current study in 1st line metastatic melanoma evaluates combination of DTIC (a global standard of care) plus IPI. Methods: In this double-blind phase 3 study, patients (pts) with metastatic melanoma, ECOG PS 0/1, and no prior therapy for advanced disease, were randomized 1:1 to IPI (10 mg/kg) + DTIC (850 mg/m2) or placebo + DTIC (850 mg/m2) at Wks 1, 4, 7, 10 followed by DTIC q3 wks through Wk 22 (induction). Eligible pts received IPI or placebo q12 wks as maintenance. Primary endpoint was OS; 2-sided log-rank test was performed, stratified by baseline M stage and ECOG PS. Results: Of 502 pts, 56% had M1c disease, 40% elevated LDH, and 26% adjuvant therapy. 37% in IPI + DTIC and 65% in DTIC alone arms received 4 induction doses. A significant improvement in OS (HR=0.72; P=0.0009) and higher estimated 1, 2 and 3 yr survival rates were seen with IPI + DTIC (Table). 56% in IPI +DTIC (n=247) and 27% in DTIC alone (n=251) arms had grade 3/4 adverse events (AEs, regardless of attribution), including: elevated ALT (22% vs 1%); diarrhea (4% vs 0%); rash (1% vs 0%). No intestinal perforations or hypophysitis were noted. There were no drug-related deaths in IPI + DTIC and one in DTIC alone arm [gastrointestinal (GI) hemorrhage]. Conclusions: IPI (10mg/kg) + DTIC significantly improved OS in 1st line metastatic melanoma vs DTIC alone; durable survival and objective responses were noted in some pts after follow-up for up to 4yrs. Type of AEs was consistent with prior IPI studies; however, frequencies of some AEs differed with a higher transaminitis and lower diarrhea/colitis/ GI perforation rates than expected. No drug-related deaths were noted in IPI arm. OS benefit of IPI is confirmed in treatment-naive metastatic melanoma.

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Mapping human somatosensory cortex in individual subjects with 7T functional MRI

Functional magnetic resonance imaging (fMRI) is now routinely used to map the topographic organization of human visual cortex. Mapping the detailed topography of somatosensory cortex, however, has proven to be more difficult. Here we used the increased blood-oxygen-level-dependent contrast-to-noise ratio at ultra-high field (7 Tesla) to measure the topographic representation of the digits in human somatosensory cortex at 1 mm isotropic resolution in individual subjects. A "traveling wave" paradigm was used to locate regions of cortex responding to periodic tactile stimulation of each distal phalangeal digit. Tactile stimulation was applied sequentially to each digit of the left hand from thumb to little finger (and in the reverse order). In all subjects, we found an orderly map of the digits on the posterior bank of the central sulcus (postcentral gyrus). Additionally, we measured event-related responses to brief stimuli for comparison with the topographic mapping data and related the fMRI responses to anatomical images obtained with an inversion-recovery sequence. Our results have important implications for the study of human somatosensory cortex and underscore the practical utility of ultra-high field functional imaging with 1 mm isotropic resolution for neuroscience experiments. First, topographic mapping of somatosensory cortex can be achieved in 20 min, allowing time for further experiments in the same session. Second, the maps are of sufficiently high resolution to resolve the representations of all five digits and third, the measurements are robust and can be made in an individual subject. These combined advantages will allow somatotopic fMRI to be used to measure the representation of digits in patients undergoing rehabilitation or plastic changes after peripheral nerve damage as well as tracking changes in normal subjects undergoing perceptual learning.

Effect of ipilimumab at 10 mg/kg on disease control in patients (pts) with M1c-stage melanoma in relation to baseline lactate dehydrogenase (LDH) levels

9041

Background: Ipilimumab, a fully human, anti-cytotoxic T-lymphocyte antigen-4 monoclonal antibody, enhances antitumor immunity. Ipilimumab is clinically active in advanced melanoma, with a 1-year survival rate of ∼50% in Phase II studies (Wolchok et al. CRI-CVC annual meeting 2008. Oral presentation). Serum LDH level is an independent prognostic factor for malignant melanoma, and is strongly predictive of reduced survival in stage IV disease (Bedikian et al. J Clin Oncol. 2006;24:4738–4745.). This analysis evaluated the association between baseline LDH levels and disease control (stable or reduced measurable tumor burden) in previously treated pts with M1c-stage melanoma (metastasis to vital organs other than the lungs) who received ipilimumab in 2 recently completed Phase II studies (CA184008 and 022). Methods: Ipilimumab at 10 mg/kg was given every 3 weeks (Q3W) × 4; eligible pts could continue to receive ipilimumab Q12W beginning at Week 24. In study 022, pts were randomized to receive ipilimumab induction dosing at 0.3, 3.0, or 10 mg/kg Q3W × 4; study 008 was a single- arm trial of ipilimumab at 10 mg/kg. Disease control data were pooled from the 2 Phase II studies for pts treated with ipilimumab at 10 mg/kg and stratified by normal and elevated (>1× upper normal limit [UNL]) LDH levels. Elevated LDH was not capped. Results: For 227 pts treated at 10 mg/kg, 123 had M1c-stage disease: 42 had normal LDH and 81 had LDH >1 × UNL (of which 32 had LDH 2 × UNL). Among these 123 pts, 17/81 (21.0%) [95% CI 12.7–31.5] with elevated LDH levels experienced disease control, whereas 12/42 (28.6%) [95% CI 15.7–44.6] with LDH levels at or below the UNL experienced disease control. Conclusions: Our data show that ipilimumab exerts similar disease control in pts with normal and elevated LDH levels. Ipilimumab therefore appears to have clinical activity in the form of disease control in pts with a very poor prognosis, i.e., M1c-stage melanoma and elevated LDH levels.

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Leptospirosis: case reports of an outbreak in Guyana

Although leptospirosis is a globally important zoonotic disease that affects humans on all continents, in both urban and rural areas, it often goes undiagnosed because its clinical manifestations are frequently non-specific. Even when leptospirosis is suspected, confirmation is made difficult by problems in isolating the causative organism in culture and by the low sensitivity of the available serological tests. Following torrential rains and flooding in January-February 2005, an outbreak of leptospirosis was suspected in Guyana, South America. Overall, 108 suspected cases presented at a medical post in the East Coast area of Guyana, and some of these cases are described in detail here. A better understanding of the clinical and paraclinical characteristics of leptospirosis should improve the recognition and appropriate treatment of the disease. Health education could reduce exposure, and physicians and primary healthcare workers could be made more aware of the signs and symptoms of leptospirosis.