Timothy J Wilkin

Weill Cornell Medical College, New York City, New York, United States

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Publications (43)227.9 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The 17th Conference on Retroviruses and Opportunistic Infections maintained its tradition of being the preeminent forum for detailing the state-of-the-art of antiretroviral therapy. Abundant new and updated information was presented on investigational drugs, approaches to the management of treatment-naive and -experienced patients, the use of drugs for prevention of mother-to-child HIV-1 transmission, and HIV resistance to antiretroviral drugs. Of particular note were the continued advances in antiretroviral treatment and research emanating from resource-limited settings and from large clinical trials to determine the optimal initial antiretroviral drug regimen. Several interesting smaller studies were focused on HIV-1 pathogenesis and persistent viremia.
    Topics in HIV medicine: a publication of the International AIDS Society, USA 05/2014; 18(2):66-92.
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    ABSTRACT: Simplified maintenance therapy with ritonavir-boosted atazanavir (ATV/r) provides an alternative treatment option for HIV-1 infection that spares nucleoside analogs (NRTI) for future use and decreased toxicity. We hypothesized that the level of immune activation (IA) and recovery of lymphocyte populations could influence virologic outcomes after regimen simplification. Thirty-four participants with virologic suppression ≥48 weeks on antiretroviral therapy (2 NRTI plus protease inhibitor) were switched to ATV/r alone in the context of the ACTG 5201 clinical trial. Flow cytometric analyses were performed on PBMC isolated from 25 patients with available samples, of which 24 had lymphocyte recovery sufficient for this study. Assessments included enumeration of T-cells (CD4/CD8), natural killer (NK) (CD3+CD56+CD16+) cells and cell-associated markers (HLA-DR, CD's 38/69/94/95/158/279). Eight of the 24 patients had at least one plasma HIV-1 RNA level (VL) >50 copies/mL during the study. NK cell levels below the group median of 7.1% at study entry were associated with development of VL >50 copies/mL following simplification by regression and survival analyses (p = 0.043 and 0.023), with an odds ratio of 10.3 (95% CI: 1.92-55.3). Simplification was associated with transient increases in naïve and CD25+ CD4+ T-cells, and had no impact on IA levels. Lower NK cell levels prior to regimen simplification were predictive of virologic rebound after discontinuation of nucleoside analogs. Regimen simplification did not have a sustained impact on markers of IA or T lymphocyte populations in 48 weeks of clinical monitoring. ClinicalTrials.gov NCT00084019.
    PLoS ONE 01/2014; 9(5):e95524. · 3.53 Impact Factor
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    ABSTRACT: Objectives To evaluate an external quality assurance (EQA) program for the laboratory diagnosis of human papillomavirus (HPV) disease that was established to improve international research capability within the Division of AIDS at the National Institute of Allergy and Infectious Disease-supported Adult AIDS Clinical Trials Group network. Methods A three-component EQA scheme was devised comprising assessments of diagnostic accuracy of cytotechnologists and pathologists using available EQA panels, review of quality and accuracy of clinical slides from local sites by an outside expert, and HPV DNA detection using a commercially available HPV test kit. Results Seven laboratories and 17 pathologists in Africa, India, and South America participated. EQA scores were suboptimal for EQA proficiency testing panels in three of seven laboratories. There was good agreement between the local laboratory and the central reader 70% of the time (90% confidence interval, 42%-98%). Performance on the College of American Pathologists' HPV DNA testing panel was successful in all laboratories tested. Conclusions The prequalifying EQA round identified correctable issues that will improve the laboratory diagnosis of HPV-related cervical disease at the participating international study sites and will provide a mechanism for ongoing education and continuous quality improvement.
    American Journal of Clinical Pathology 12/2013; 140(6):881-9. · 2.88 Impact Factor
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    ABSTRACT: OBJECTIVE:: To evaluate the safety and efficacy of topical cidofovir for treatment of high-grade squamous perianal and vulvar intraepithelial neoplasia (PAIN and VIN) lesions in HIV-positive individuals. DESIGN:: Phase IIa prospective multicenter trial conducted at eight clinical sites through the AIDS Malignancy Consortium (AMC) METHODS:: HIV-positive patients with biopsy-proven high-grade PAIN that was ≥ 3 cm were enrolled. PAIN biopsy specimens were assessed for HPV using PCR and type-specific HPV probing. Subjects applied 1% topical cidofovir to PAIN and VIN (if present) for 6 two-week cycles. Results were designated as complete response (CR), partial response (PR) (> 50% reduction in size), stable disease (SD), or progressive disease (PD). RESULTS:: Twenty-four men and 9 women (8 with high-grade VIN as well) were enrolled. Mean age was 44 years, mean CD4+ count was 412 cells/μl. HPV DNA (most commonly HPV16) was detected in all pre-treatment study specimens. Twenty six (79%) subjects completed treatment per protocol-CR: 5 (15%); PR: 12 (36%), SD: 7 (21%); PD: 2 (6%) (1 with a superficially invasive cancer and 1 with new area of high-grade PAIN). Treatment was well tolerated with most common adverse events being mild to moderate affecting lesional skin: pain/burning/irritation (25 subjects) and ulceration (13 subjects). CONCLUSIONS:: Topical cidofovir had 51% efficacy in the short-term treatment of high-grade PAIN and VIN with acceptable toxicity in HIV-positive individuals. Randomized control studies with more prolonged treatment courses and longer follow-up to assess the durability of the response are needed.
    AIDS (London, England) 10/2012; · 4.91 Impact Factor
  • Cynthia Firnhaber, Timothy Wilkin
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    ABSTRACT: Human papillomavirus (HPV) is the etiological agent for cervical cancer and a large majority of anal cancers worldwide. In 2006 two preventive vaccines against the HPV were approved by the US Food and Drug Administration and have since been approved in over 100 countries. HIV-infected populations are at an increased risk for HPV-related cancers. None of the efficacy trials for these vaccines included HIV-infected populations. However, studies in HIV-infected children and adult men show that the vaccine is safe and highly immunogenic. Studies evaluating the vaccine in HIV-infected women are in progress. Based on these studies, the American Council on Immunization Practices recommends HPV vaccination for all HIV-infected children and young adults up to age 26 years. HPV vaccine policies in resource-limited countries, many of which have a high prevalence of HIV infection, are still being developed. Future studies should examine the role of HPV vaccination for older HIV-infected adults who likely have ongoing HPV infection.
    Current HIV/AIDS Reports 06/2012; 9(3):278-86.
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    ABSTRACT: Despite viral suppression, antiretroviral therapy (ART) does not restore CD4(+) T-cell counts in many patients infected with human immunodeficiency virus type 1 (HIV-1). In a single-arm pilot trial involving ART recipients with suppressed plasma levels of HIV-1 RNA for at least 48 weeks and stable suboptimal CD4(+) T-cell recovery, subjects added maraviroc, a CCR5 antagonist, to their existing ART for 24 weeks. After stopping maraviroc, they were followed for an additional 24 weeks. A Wilcoxon signed-rank test was used to evaluate whether maraviroc was associated with an increase of at least 20 cells/µL in the CD4(+) T-cell count. A total of 34 subjects were enrolled. The median age was 50 years, and the median baseline CD4(+) T-cell count was 153 cells/µL. The median increase in CD4(+) T-cell count from baseline to week 22/24 was 12 cells/µL (90% confidence interval, 1-22). A CD4(+) T-cell count increase of at least 20 cells/µL was not detected (P = .97). Markers of immune activation and apoptosis decreased during maraviroc intensification; this decline partially reversed after discontinuing maraviroc. Adding maraviroc to suppressive ART for 24 weeks was not associated with an increase in CD4(+) T-cell counts of at least 20 cells/µL. Further studies of CCR5 antagonists in the dampening of immune activation associated with HIV infection are warranted. Clinical Trials Registration. NCT 00709111.
    The Journal of Infectious Diseases 06/2012; 206(4):534-42. · 5.85 Impact Factor
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    ABSTRACT: The 19th Conference on Retroviruses and Opportunistic Infections (CROI) highlighted new information and provided in-depth discussion on advances in antiretroviral therapy (ART). Data regarding investigational drugs, including integrase strand transfer inhibitors (InSTIs) and zinc-finger nucleases disrupting CC chemokine receptor 5 (CCR5), were presented. Treatment trials in treatment-naive and treatment-experienced patients added to the knowledge base of which antiretroviral agents to initiate and when. Data from trials and observational cohorts suggested that, for patients on successful ART in resource-rich settings, mortality from non-HIV-related diseases may surpass that from HIV-related diseases, and overall lifespan may be nearing that of people without HIV infection. In resource-limited settings (RLS), prevention of mother-to-child transmission (PMTCT) and ART scale-up remained priorities. New data on antiretroviral resistance in RLS and on the implications of low-frequency mutations were presented.
    Topics in antiviral medicine. 06/2012; 20(2):61-86.
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    Timothy J Wilkin, Roy M Gulick
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    ABSTRACT: CCR5 antagonists inhibit HIV-1 entry by blocking the interaction of HIV-1 with the CCR5 cellular receptor. In patients with established HIV-1 infection, some viral strains use an alternative coreceptor for HIV-1 entry, CXCR4; CCR5 antagonists are not effective in patients harboring these viral strains. Coreceptor tropism testing of viral strains in an individual patient is necessary prior to treating with a CCR5 antagonist. There is one CCR5 antagonist, maraviroc, that is FDA-approved for treatment of HIV-1 infection. This drug is used most commonly for the treatment of HIV-1 infection in patients who have failed other antiretroviral regimens. In addition to virologic effects, CCR5 antagonists are under investigation for immune-modulating effects and for HIV-1 prevention. Ongoing research will further elucidate the role of CCR5 antagonists in combating HIV disease.
    Annual review of medicine 01/2012; 63:81-93. · 9.94 Impact Factor
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    ABSTRACT: Adding an immune-enhancing agent to initial antiretroviral therapy (ART) for HIV is a potential strategy to ensure that patients achieve optimal immune response. Using a mathematical model of HIV disease and treatment, we evaluated the treatment benefits and cost-effectiveness of adding a hypothetical immune-enhancing agent to the initial 6 months of ART. We assumed that the additional agent would result in a higher CD4 increase that would provide clinical benefit. The additional cost ($1,900/month) was based on the cost of a drug currently under investigation for immune enhancement. Outcomes included projected life expectancy and cost-effectiveness in 2009 US dollars/quality-adjusted life year (QALY) with costs and QALYs discounted at 3% annually. Compared to standard ART, immune-enhanced ART resulting in an additional 40 CD4 cell/µL increase at 6 months yields a 2.4 month projected undiscounted life expectancy increase with a cost-effectiveness ratio of $107,600/QALY. Achieving a cost-effectiveness ratio <$100,000/QALY requires a >43 CD4 cell/µL improvement, or >19 cells/µL if immune-enhancing agent costs are halved. In addition to showing clinical efficacy, investigational immune enhancement agents need to increase CD4 counts more than has been previously observed or have a lower cost to be considered cost-effective in the United States.
    HIV Clinical Trials 01/2012; 13(1):1-10. · 2.30 Impact Factor
  • Luis F Barroso, Timothy Wilkin
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    ABSTRACT: Human papillomavirus (HPV) is an extremely prevalent sexually transmitted infection that is typically acquired soon after onset of sexual activity. The burden of HPV-related malignant and nonmalignant disease is high in men and women. High-risk or oncogenic types of HPV cause cervical, vaginal, and vulvar cancer in women. These types have also been shown to cause penile cancer in men and a substantial proportion of oropharyngeal and anal malignancy in men and women. Low-risk types of HPV cause anogenital warts. Prevention of penile, anal, and oropharyngeal cancers and anogenital warts represents potential benefits of the HPV vaccine in men. This review focuses on HPV disease in men, existing data on HPV vaccination in men, and various factors associated with the decision to vaccinate boys and young men, as well as the timing of vaccination.
    Current Infectious Disease Reports 04/2011; 13(2):175-81.
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    ABSTRACT: The enhanced-sensitivity Trofile assay (TF-ES; Monogram Biosciences) was used to retest coreceptor tropism samples from 4 different cohorts of HIV-1-infected patients. Nine percent to 26% of patients with CCR5-tropic virus by the original Trofile assay had CXCR4-using virus by TF-ES. Lower CD4 cell counts were associated with CXCR4-using virus in all cohorts.
    Clinical Infectious Diseases 04/2011; 52(7):925-8. · 9.37 Impact Factor
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    ABSTRACT: Human immunodeficiency virus type 1 (HIV-1)-infected men are at increased risk for anal cancer. Human papillomavirus (HPV) vaccination may prevent anal cancer caused by vaccine types. AIDS Malignancy Consortium Protocol 052 is a single-arm, open-label, multicenter clinical trial to assess the safety and immunogenicity of the quadrivalent HPV (types 6, 11, 16, and 18) vaccine in HIV-1-infected men. Men with high-grade anal intraepithelial neoplasia or anal cancer by history or by screening cytology or histology were excluded. Men received 0.5 mL intramuscularly at entry, week 8, and week 24. The primary end points were seroconversion to vaccine types at week 28, in men who were seronegative and without anal infection with the relevant HPV type at entry, and grade 3 or higher adverse events related to vaccination. There were no grade 3 or greater adverse events attributable to vaccination among the 109 men who received at least 1 vaccine dose. Seroconversion was observed for all 4 types: type 6 (59 [98%] of 60), type 11 (67 [99%] of 68), type 16 (62 [100%] of 62), and type 18 (74 [95%] of 78). No adverse effects on CD4 counts and plasma HIV-1 RNA levels were observed. The quadrivalent HPV vaccine appears safe and highly immunogenic in HIV-1-infected men. Efficacy studies in HIV-1-infected men are warranted. Clinical trials registration. NCT 00513526.
    The Journal of Infectious Diseases 10/2010; 202(8):1246-53. · 5.85 Impact Factor
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    ABSTRACT: Vicriviroc, an investigational CCR5 antagonist, demonstrated short-term safety and antiretroviral activity. Phase 2, double-blind, randomized study of vicriviroc in treatment-experienced subjects with CCR5-using HIV-1. Vicriviroc (5, 10, or 15 mg) or placebo was added to a failing regimen with optimization of background antiretroviral medications at day 14. Subjects experiencing virologic failure and subjects completing 48 weeks were offered open-label vicriviroc. One hundred eighteen subjects were randomized. Virologic failure (<1 log10 decline in HIV-1 RNA > or =16 weeks postrandomization) occurred by week 48 in 24 of 28 (86%), 12 of 30 (40%), 8 of 30 (27%), 10 of 30 (33%) of subjects randomized to placebo, 5, 10, and 15 mg, respectively. Overall, 113 subjects received vicriviroc at randomization or after virologic failure, and 52 (46%) achieved HIV-1 RNA <50 copies per milliliter within 24 weeks. Through 3 years, 49% of those achieving suppression did not experience confirmed viral rebound. Dual or mixed-tropic HIV-1 was detected in 33 (29%). Vicriviroc resistance (progressive decrease in maximal percentage inhibition on phenotypic testing) was detected in 6 subjects. Nine subjects discontinued vicriviroc due to adverse events. Vicriviroc seems safe and demonstrates sustained virologic suppression through 3 years of follow-up. Further trials of vicriviroc will establish its clinical utility for the treatment of HIV-1 infection.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 08/2010; 54(5):470-6. · 4.65 Impact Factor
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    Infectious Agents and Cancer 01/2010; 5:1-2.
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    ABSTRACT: Purpose: Lower CD4+ T-cell counts are related to increased morbidity and mortality despite virologic suppression. CCR5 antagonists are associated with robust CD4+ T-cell responses. We examined the relationship of CCR5 antagonists to CD4+ T-cell gains. Design: Meta-regression of recent phase 2-3 trials evaluating new antiretroviral agents in treatment-experienced subjects. Methods: We analyzed the relationship of CCR5 antagonists to CD4+ T-cell count increase 24 weeks after initiating the new regimen using a linear model with generalized estimating equations controlling for differing rates of virologic suppression. Each treatment group was treated as a data point weighted by sample size. Results: We included 46 treatment groups from 17 trials (11 groups from 5 trials used CCR5 antagonists). Controlling for average baseline HIV-1 RNA and proportion of subjects achieving HIV-1 RNA <50 copies/mL, use of a CCR5 antagonist was associated with an additional significant CD4+ T-cell gain of +30/μL (95% CI, 19-42) at 24 weeks compared to treatment groups not using a CCR5 antagonist. Conclusions: Use of a CCR5 antagonist was associated with an enhanced CD4+ T-cell count response independent of virologic suppression. This observation supports further evaluation of CCR5 antagonists in patients with discordant immunologic and virologic responses to ART.
    HIV Clinical Trials 01/2010; 11(6):351-8. · 2.30 Impact Factor
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    ABSTRACT: The enhanced-sensitivity Trofile assay (Monogram Biosciences) was used to retest coreceptor use at both study screening and study entry for 118 treatment-experienced subjects in AIDS Clinical Trials Group A5211 who had CCR5-tropic (R5) virus detected by the original Trofile assay at study screening. Among 90 recipients of vicriviroc, a significantly (P< .001) greater mean reduction in HIV-1 RNA was observed in 72 subjects with R5 virus versus 15 subjects reclassified as having dual/mixed-tropic viruses at screening: -1.11 versus -0.09 log(10) copies/mL at day 14 and -1.91 versus -0.57 log(10) copies/mL at week 24, respectively. Results suggest that the enhanced-sensitivity assay is a better screening tool for determining patient eligibility for CCR5 antagonist therapy.
    The Journal of Infectious Diseases 12/2009; 200(11):1724-8. · 5.85 Impact Factor
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    ABSTRACT: Detection of CXCR4-using human immunodeficiency virus by the Trofile assay was compared to that by assays using virus isolates or replication-competent recombinants. Concordance with the Trofile assay was good, but assays using replicating viruses did not increase substantially the ability to detect the presence of CXCR4-using virus.
    Journal of clinical microbiology 07/2009; 47(8):2604-6. · 4.16 Impact Factor
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    ABSTRACT: Lack of functional CCR5 increases the severity of certain viral infections, including West Nile virus and tickborne encephalitis. In a phase II trial of the investigational CCR5 antagonist vicriviroc (AIDS Clinical Trials Group protocol A5211), 4 lymphomas occurred in study patients who received vicriviroc. Because of the known association between unregulated Epstein-Barr virus (EBV) replication and lymphoma in immunocompromised patients, we evaluated whether vicriviroc exposure was associated with lymphoma EBV antigen positivity and/or had an effect on plasma levels of EBV DNA. Clinical findings for all 4 patients enrolled in the A5211 study who developed lymphoma (2 Hodgkin and 2 non-Hodgkin) were reviewed, and tumor specimens were assessed for evidence of ongoing EBV replication. Longitudinal plasma samples from 116 patients in the A5211 study were analyzed, and EBV DNA was quantified by real-time polymerase chain reaction. Plasma EBV DNA was not detected in the 2 patients with non-Hodgkin lymphoma; both patients with Hodgkin lymphoma who had samples tested had EBV DNA levels <3200 copies/mL. One patient with Hodgkin lymphoma had a lymph node core biopsy specimen that was strongly positive for EBV; the other 3 lymphomas were histochemically EBV negative. None of the 116 patients with available samples experienced sustained increases in plasma EBV levels. CCR5 antagonism by vicriviroc treatment in treatment-experienced patients was not associated with reactivation of EBV infection.
    Clinical Infectious Diseases 03/2009; 48(5):642-9. · 9.37 Impact Factor
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    ABSTRACT: Simplified maintenance therapy with ritonavir-boosted atazanavir (ATV/RTV) alone is attractive because of nucleoside reverse-transcriptase inhibitor (NRTI)-sparing benefits, low pill burden, once-daily dosage, and safety. Subjects with virologic suppression after > or = 48 weeks of initial antiretroviral therapy with 2 NRTIs and a protease inhibitor (PI) were enrolled. Subjects switched to ATV/RTV at entry and discontinued NRTIs after 6 weeks. The primary end point was time to virologic failure (confirmed HIV-1 RNA level > or = 200 copies/mL). Drug resistance at virologic failure was evaluated by standard genotyping and single-genome sequencing (SGS). Residual viremia (1.1-49 copies/mL) was measured by single-copy assay. Thirty-four subjects simplified to ATV/RTV alone, of whom 30 (88%) did not experience virologic failure by 48 weeks after simplification. Residual viremia did not change significantly after NRTI discontinuation among those without virologic failure but did increase 4-12 weeks before confirmed virologic failure. No major PI-resistance mutations were identified at virologic failure by standard genotyping or SGS. In this pilot study, simplified maintenance therapy with ATV/RTV alone maintained viral suppression in most subjects through 48 weeks. PI resistance was not detected among subjects experiencing virologic failure. Larger, randomized trials are warranted to further define the efficacy and safety of this strategy.
    The Journal of Infectious Diseases 03/2009; 199(6):866-71. · 5.85 Impact Factor
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    Timothy J Wilkin, Roy M Gulick
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    ABSTRACT: The optimal time to start antiretroviral therapy (ART) for human immunodeficiency virus (HIV)-infected individuals remains uncertain. Although current ART regimens are effective in suppressing viremia and enhancing immune function and are increasingly convenient and well tolerated, ongoing concerns remain about adherence, drug-related toxicities, drug resistance, and cost. Although few clinical trials results are currently available to inform the question of when to start ART, large clinical cohorts clearly have demonstrated the benefits of earlier initiation of ART for reducing both HIV-related and non-HIV-related clinical events. Additional data suggest that the strategy of earlier initiation of ART is cost-effective and efficient. Consequently, many antiretroviral guidelines from around the world now recommend routine initiation of ART when the CD4 cell count decreases to <350 cells/microL or at higher CD4 cell counts for certain subgroups of HIV-infected individuals, such as pregnant and/or breast-feeding women and persons with HIV-related nephropathy or hepatitis virus coinfection. Additional cohort and clinical trials data are needed.
    Clinical Infectious Diseases 01/2009; 47(12):1580-6. · 9.37 Impact Factor

Publication Stats

1k Citations
227.90 Total Impact Points

Institutions

  • 2003–2014
    • Weill Cornell Medical College
      • Division of Infectious Diseases
      New York City, New York, United States
  • 2013
    • National Institute of Allergy and Infectious Diseases
      Maryland, United States
  • 2012
    • University of Johannesburg
      • Department of Medicine
      Johannesburg, Gauteng, South Africa
  • 2009
    • Harvard Medical School
      Boston, Massachusetts, United States
    • Brigham and Women's Hospital
      • Department of Medicine
      Boston, MA, United States
    • Johns Hopkins University
      Baltimore, Maryland, United States
  • 2006–2009
    • Cornell University
      • Department of Medicine
      Ithaca, New York, United States