Wilms' tumor 1 (WT1) antigen is overexpressed in Kaposi Sarcoma and is regulated by KSHV vFLIP.

In people living with HIV, Kaposi Sarcoma (KS), a vascular neoplasm caused by KS herpesvirus (KSHV/HHV-8), remains one of the most common malignancies worldwide. Individuals living with HIV, receiving otherwise effective antiretroviral therapy, may present with extensive disease requiring chemotherapy. Hence, new therapeutic approaches are needed. The Wilms' tumor 1 (WT1) protein is overexpressed and associated with poor prognosis in several hematologic and solid malignancies and has shown promise as an immunotherapeutic target. We found that WT1 was overexpressed in >90% of a total 333 KS biopsies, as determined by immunohistochemistry and image analysis. Our largest cohort from ACTG, consisting of 294 cases was further analyzed demonstrating higher WT1 expression was associated with more advanced histopathologic subtypes. There was a positive correlation between the proportion of infected cells within KS tissues, assessed by expression of the KSHV-encoded latency-associated nuclear antigen (LANA), and WT1 positivity. Areas with high WT1 expression showed sparse T-cell infiltrates, consistent with an immune evasive tumor microenvironment. We show that major oncogenic isoforms of WT1 are overexpressed in primary KS tissue and observed WT1 upregulation upon de novo infection of endothelial cells with KSHV. KSHV latent viral FLICE-inhibitory protein (vFLIP) upregulated total and major isoforms of WT1, but upregulation was not seen after expression of mutant vFLIP that is unable to bind IKKÆ´ and induce NFκB. siRNA targeting of WT1 in latent KSHV infection resulted in decreased total cell number and pAKT, BCL2 and LANA protein expression. Finally, we show that ESK-1, a T cell receptor-like monoclonal antibody that recognizes WT1 peptides presented on MHC HLA-A0201, demonstrates increased binding to endothelial cells after KSHV infection or induction of vFLIP expression. We propose that oncogenic isoforms of WT1 are upregulated by KSHV to promote tumorigenesis and immunotherapy directed against WT1 may be an approach for KS treatment.

Predictive Value of Serum Biomarkers for Response of Limited-Stage AIDS-Associated Kaposi Sarcoma to Antiretroviral Therapy With or Without Concomitant Chemotherapy in Resource-Limited Settings.

BACKGROUND: Guidelines for limited-stage human immunodeficiency virus-associated Kaposi sarcoma (AIDS/KS) recommend antiretroviral therapy (ART) as initial treatment. However, many such individuals show worsening KS and require additional chemotherapy. Methods to identify such patients are lacking. SETTING: We studied whether serum levels of biomarkers associated with angiogenesis, systemic inflammation, and immune activation, which are elevated in HIV-infected individuals and implicated in the development of KS, could prospectively identify individuals with limited-stage AIDS-KS who would benefit from chemotherapy administered with ART. METHODS: Serum specimens were obtained from participants in a randomized trial evaluating the value of adding oral etoposide chemotherapy to ART in treatment-naïve people with limited-stage AIDS-KS in resource-limited settings. Serum biomarkers of inflammation (C-reactive protein [CRP], interleukin [IL]-6, IL-8, IL-10, granulocyte colony stimulating factor, soluble tumor necrosis factor receptor-2), immune system activation (soluble IL-2 receptor alfa, C-X-C motif chemokine ligand 10/interferon gamma-induced protein 10, C-C motif ligand 2/monocyte chemoattractant protein 1), and angiogenesis (vascular endothelial growth factor, matrix metalloproteinase-2, -9, endoglin, hepatocyte growth factor) were measured at entry to determine whether baseline levels are associated with KS response. On-treatment changes in biomarker levels were determined to assess how etoposide modifies the effects of ART. RESULTS: Pretreatment CRP and IL-10 were higher in those whose KS progressed, and lowest in those who had good clinical responses. Pretreatment CRP, IL-6, and soluble tumor necrosis factor receptor-2 showed significant associations with KS progression at the week-48 primary endpoint. Immediate etoposide led to lower inflammation biomarker levels compared with ART alone. Early KS progression was associated with elevated pretreatment levels of inflammation-associated biomarkers and increasing levels post-treatment. CONCLUSIONS: Quantifying serum biomarkers, especially CRP, may help identify persons with AIDS-KS who would benefit from early introduction of chemotherapy in addition to ART.

Quality Assurance in Clinical Trials Requiring Radiation Therapy in Sub-Saharan Africa.

PURPOSE: Given the increasing availability of radiation therapy in sub-Saharan Africa, clinical trials that include radiation therapy are likely to grow. Ensuring appropriate delivery of radiation therapy through rigorous quality assurance is an important component of clinical trial execution. We reviewed the process for credentialing radiation therapy sites and radiation therapy quality assurance through the Imaging and Radiation Oncology Core (IROC) Houston Quality Assurance Center for AIDS Malignancy Consortium (AMC)-081, a multicenter study of cisplatin and radiation therapy for women with locally advanced cervical cancer living with HIV, conducted by the AIDS Malignancy Consortium at 2 sites in South Africa and Zimbabwe. METHODS AND MATERIALS: Women living with HIV with newly diagnosed stage IB2, IIA (>4 cm), IIB-IVA cervical carcinoma (per the 2009 International Federation of Gynecology and Obstetrics [FIGO] staging classifications) were enrolled in AMC-081. They received 3-dimensional conformal external beam radiation therapy (EBRT) to the pelvis (41.4-45 Gy) using a linear accelerator, high-dose-rate brachytherapy (6-9 Gy to point A with each fraction and up to 4 fractions), and concurrent weekly cisplatin (40 mg/m2). IROC reviewed EBRT and brachytherapy quality assurance records after treatment. RESULTS: All of the 38 women enrolled in AMC-081 received ±5% of the protocol-specified prescribed dose of EBRT. Geometry of brachytherapy applicator placement was scored as per protocol in all implants. Doses to points A and B, International Commission on Radiation Units and Measurements (ICRU) bladder, or ICRU rectum required correction by IROC in >50% of the implants. In the final evaluation, 58% of participants (n = 22) were treated per protocol, 40% (n = 15) had minor protocol deviations, and 3% (n = 1) had major protocol deviations. No records were received within 60 days of treatment completion as requested in the protocol. CONCLUSIONS: Major radiation therapy deviations were low, but timely submission of radiation therapy data did not occur. Future studies, especially those that include specialized radiation therapy techniques such as stereotactic or intensity-modulated radiation therapy, will require pathways to ensure timely and adequate quality assurance.

Challenges of HIV Lymphoma Clinical Trials in Africa: Lessons From the AIDS Malignancy Consortium 068 Study.

The purpose of this article is to describe lessons from the first lymphoma clinical trial conducted by the AIDS Malignancy Consortium (AMC) in sub-Saharan Africa (SSA). AMC-068 was a randomized phase II comparison of intravenous versus oral chemotherapy for HIV-positive diffuse large B-cell lymphoma. Opening in 2016, AMC-068 planned to enroll 90 patients (45 per arm) in Kenya, Malawi, Uganda, and Zimbabwe over 24 months and follow patients for 24 months to assess overall survival. In 2018, the study closed after screening 42 patients but enrolling only 7. Challenges occurred during protocol development, pre-activation, and postactivation. During protocol development (2011-2012), major obstacles were limited baseline data to inform study design; lack of consensus among investigators and approving bodies regarding appropriateness of the oral regimen and need for randomized comparison with cyclophosphamide, doxorubicin, vincristine, and prednisone; and heterogeneity across sites in local standards for diagnosis, staging, and treatment. During pre-activation (2012-2016), challenges included unexpected length and layers of regulatory approval across multiple countries, need to upgrade pathology capacity at sites, need to augment existing chemotherapy infusion capacity at sites, and procurement issues for drugs and supplies. Finally, during postactivation (2016-2018), challenges included long delays between symptom onset and screening entry for many patients, leading to compromised performance status and organ function; other patient characteristics that frequently led to exclusion, including high tumor proliferative index or other pathologic features that were disallowed; and costs of routine diagnostic procedures often being borne by patients, which also contributed to pre-enrollment delays. Lessons from AMC-068 are being applied to the design and conduct of new AMC lymphoma trials in SSA, and the study has contributed to a strong operational foundation that will support innovative clinical trials in the future.

Clinical Trials for Treatment and Prevention of HIV-Associated Malignancies in Sub-Saharan Africa: Building Capacity and Overcoming Barriers.

PURPOSE: The aim of this study was to review the current status of clinical trials for HIV-associated malignancies in people living with HIV in sub-Saharan Africa (SSA) and efforts made by the AIDS Malignancy Consortium (AMC) to build capacity in SSA for HIV malignancy research. METHODS: All malignancy-related clinical trials in 49 SSA countries on ClinicalTrials.gov were reviewed and evaluated for inclusion and exclusion criteria pertaining to HIV status. Additional studies by AMC in SSA were compiled from Web-based resources, and narrative summaries were prepared to highlight AMC capacity building and training initiatives. RESULTS: Of 96 cancer trials identified in SSA, only 11 focused specifically on people living with HIV, including studies in Kaposi sarcoma, cervical dysplasia and cancer, non-Hodgkin lymphoma, and ocular surface squamous neoplasia. Recognizing the increasing cancer burden in the region, AMC expanded its clinical trial activities to SSA in 2010, with 4 trials completed to date and 6 others in progress or development, and has made ongoing investments in developing research infrastructure in the region. CONCLUSION: As the HIV-associated malignancy burden in SSA evolves, research into this domain has been limited. AMC, the only global HIV malignancy-focused research consortium, not only conducts vital HIV-associated malignancies research in SSA, but also develops pathology, personnel, and community-based infrastructure to meet these challenges in SSA. Nonetheless, there is an ongoing need to build on these efforts to improve HIV-associated malignancies outcomes in SSA.

Early Progression and Immune Reconstitution Inflammatory Syndrome During Treatment of Mild-To-Moderate Kaposi Sarcoma in Sub-Saharan Africa and South America: Incidence, Long-Term Outcomes, and Effects of Early Chemotherapy.

BACKGROUND: Early progression of AIDS-associated Kaposi sarcoma (KS-PD) and immune reconstitution inflammatory syndrome (KS-IRIS) sometimes occur after the initiation of antiretroviral therapy (ART). METHODS: Early KS-PD and KS-IRIS were assessed in the A5264/AMC-067 trial in which participants with mild-to-moderate AIDS-KS were randomized to initiate ART with either immediate or as-needed oral etoposide. Early KS-PD was defined as tumor progression within 12 weeks of ART initiation. When investigators had concern that early KS-PD was KS-IRIS, additional evaluations were performed. Suspected KS-IRIS was defined as early KS-PD accompanied by a CD4 count increase of ≥50 cells per cubic millimeter or plasma HIV-1 RNA decrease of ≥0.5 log10 copies/mL. Clinical outcome was a composite end point categorized as failure, stable, and response at 48 and 96 weeks compared with baseline. RESULTS: Fifty of 190 participants had early KS-PD (27%): 28 had KS-IRIS and 22 were not evaluated for KS-IRIS. Early KS-PD and KS-IRIS incidences with immediate etoposide versus ART alone were 16% versus 39%, and 7% versus 21%, respectively. Week 48 clinical outcome was 45% failure, 18% stable, and 37% response for no early KS-PD; 82% failure, 2% stable, and 16% response for early KS-PD; and 88% failure, 0% stable, and 12% response for KS-IRIS. Cumulative incidence of KS tumor response by week 96 was 64% for no early KS-PD, 22% with early KS-PD, and 18% with KS-IRIS. CONCLUSIONS: Early KS-PD, including suspected KS-IRIS, was common after starting ART for AIDS-KS and was associated with worse long-term clinical outcomes. Starting ART concurrently with etoposide reduced the incidence of both early KS-PD and KS-IRIS compared with ART alone.

Treatment of advanced AIDS-associated Kaposi sarcoma in resource-limited settings: a three-arm, open-label, randomised, non-inferiority trial.

BACKGROUND: Optimal treatment regimens for AIDS-associated Kaposi sarcoma, a frequent contributor to morbidity and mortality among people with HIV, have not been systematically evaluated in low-income and middle-income countries, where the disease is most common. In this study, we aimed to investigate optimal treatment strategies for advanced stage disease in areas of high prevalence and limited resources. METHODS: In this open-label, non-inferiority trial, we enrolled people with HIV and advanced stage AIDS-associated Kaposi sarcoma attending 11 AIDS Clinical Trials Group sites in Brazil, Kenya, Malawi, South Africa, Uganda, and Zimbabwe. Eligible participants were randomly assigned (1:1:1) with a centralised computer system to receive either intravenous bleomycin and vincristine or oral etoposide (the investigational arms), or intravenous paclitaxel (the control arm), together with antiretroviral therapy (ART; combined efavirenz, tenofovir disoproxil fumarate, and emtricitabine). The primary outcome was progression-free survival (PFS) at week 48, using a 15% non-inferiority margin to compare the investigational groups against the active control group. Safety was assessed in all eligible treated study participants. The study was registered with ClinicalTrials.gov, NCT01435018. FINDINGS: 334 participants were enrolled between Oct 1, 2013, and March 8, 2018, when the study was closed early due to inferiority of the bleomycin and vincristine plus ART arm, as per the recommendations of the Data and Safety Monitoring Board (DSMB). The etoposide plus ART arm also closed due to inferiority in March, 2016, following a DSMB recommendation. Week-48 PFS rates were higher in the paclitaxel plus ART arm than in both investigational arms. The absolute differences in PFS were -30% (95% CI -52 to -8) for the comparison of paclitaxel plus ART (week 48 PFS 50%, 32 to 67; n=59) and etoposide plus ART (20%, 6 to 33; n=59), and -20% (-33% to -7%) for the comparison of paclitaxel plus ART (64%, 55 to 73; n=138) and bleomycin and vincristine plus ART (44%, 35 to 53; n=132). Both CIs overlapped the non-inferiority margin. The most common adverse events, in 329 eligible participants who began treatment, were neutropenia (48 [15%]), low serum albumin (33 [10%]), weight loss (29 [9%]), and anaemia (28 [9%]), occurring at similar frequency across treatment arms. INTERPRETATION: Non-inferiority of either investigational intervention was not shown, with paclitaxel plus ART showing superiority to both oral etoposide plus ART and bleomycin and vincristine plus ART, supporting its use in treating advanced AIDS-associated Kaposi sarcoma in resource-limited settings. FUNDING: US National Institute of Allergy and Infectious Diseases and National Cancer Institute, National Institutes of Health.

Cisplatin and radiation therapy in HIV-positive women with locally advanced cervical cancer in sub-Saharan Africa: A phase II study of the AIDS malignancy consortium.

PURPOSE: To determine the feasibility, safety, and tolerability of concomitant chemoradiotherapy administered at standard doses in HIV-infected women with locally-advanced cervical cancer (LACC) receiving antiretroviral therapy (ART). PATIENTS AND METHODS: Eligible participants had HIV infection and untreated, histologically-confirmed, invasive carcinoma of the uterine cervix, FIGO stages IB2, IIA (if tumor >4 cm), IIB, IIIA, IIIB, or IVA and met standard eligibility criteria. Subjects were prescribed 41.4-45 Gy external beam radiation therapy followed by high dose rate brachytherapy concomitant with up to six weekly doses of cisplatin 40 mg/m2 and were followed for 12 months. RESULTS: Sixty-four women were screened at two sites in sub-Saharan Africa, of whom 40 eligible participants were enrolled, for a screening ratio of 1.60. Of the 38 eligible participants who initiated study treatment, 31 (82%) completed treatment. By the 12-month follow-up visit, 7 women had died of disease and 29 of 31 (94%) returned for follow-up. One-year progression-free survival was 76.3% (95% CI, 59.4-86.9%), and did not significantly differ according to stage at entry (p = 0.581). Participant-reported adherence to ART was high; by 12 months, 93% of participants had an undetectable viral load. The most common grade 3 or 4 adverse event was decreased lymphocyte count that affected all treated participants. Non-hematologic serious adverse events were similar to those observed in women with LACC without HIV infection. CONCLUSIONS: The majority of HIV-infected women with LACC can complete concomitant chemoradiotherapy with the same cisplatin dose used in HIV-uninfected women with comparable tolerability and high ART adherence while on treatment.

Kaposi sarcoma.

Kaposi sarcoma (KS) gained public attention as an AIDS-defining malignancy; its appearance on the skin was a highly stigmatizing sign of HIV infection during the height of the AIDS epidemic. The widespread introduction of effective antiretrovirals to control HIV by restoring immunocompetence reduced the prevalence of AIDS-related KS, although KS does occur in individuals with well-controlled HIV infection. KS also presents in individuals without HIV infection in older men (classic KS), in sub-Saharan Africa (endemic KS) and in transplant recipients (iatrogenic KS). The aetiologic agent of KS is KS herpesvirus (KSHV; also known as human herpesvirus-8), and viral proteins can induce KS-associated cellular changes that enable the virus to evade the host immune system and allow the infected cell to survive and proliferate despite viral infection. Currently, most cases of KS occur in sub-Saharan Africa, where KSHV infection is prevalent owing to transmission by saliva in childhood compounded by the ongoing AIDS epidemic. Treatment for early AIDS-related KS in previously untreated patients should start with the control of HIV with antiretrovirals, which frequently results in KS regression. In advanced-stage KS, chemotherapy with pegylated liposomal doxorubicin or paclitaxel is the most common treatment, although it is seldom curative. In sub-Saharan Africa, KS continues to have a poor prognosis. Newer treatments for KS based on the mechanisms of its pathogenesis are being explored.

As-Needed Vs Immediate Etoposide Chemotherapy in Combination With Antiretroviral Therapy for Mild-to-Moderate AIDS-Associated Kaposi Sarcoma in Resource-Limited Settings: A5264/AMC-067 Randomized Clinical Trial.

Background: Mild-to-moderate AIDS-associated Kaposi sarcoma (KS) often responds to antiretroviral therapy (ART) alone; the role of chemotherapy is unclear. We assessed the impact of immediate vs as-needed oral etoposide (ET) among human immunodeficiency virus (HIV)-infected individuals with mild-to-moderate KS initiating ART. Methods: Chemotherapy-naive, HIV type 1-infected adults with mild-to-moderate KS initiating ART in Africa and South America were randomized to ART (tenofovir/emtricitabine/efavirenz) alone (chemotherapy "as-needed" arm) vs ART plus up to 8 cycles of oral ET (immediate arm). Participants with KS progression on ART alone received ET as part of the as-needed strategy. Primary outcome was ordinal as follows: failure, stable, and response at 48 weeks. Secondary outcomes included time to initial KS progression, KS-associated immune reconstitution inflammatory syndrome (KS-IRIS), and KS response. Results: Of 190 randomized participants (as-needed = 94, immediate = 96), the majority were men (71%) and African (93%). Failure (53.8% vs 56.6%), stable (16.3% vs 10.8%), and response (30% vs 32.5%) did not differ between arms (as-needed vs immediate) among those with week 48 data potential (N = 163, P = .91). Time to KS progression (P = .021), KS-IRIS (P = .003), and KS response (P = .003) favored the immediate arm. Twenty-five participants died (13%). Mortality, adverse events, CD4+ T-cell changes, and HIV RNA suppression were similar at 48 weeks. Conclusions: Among HIV-infected adults with mild-to-moderate KS, immediate ET provided early, nondurable clinical benefits. By 48 weeks, no clinical benefit was observed compared to use of ET as needed. Mortality was high and tumor response was low. Clinical Trials Registration: NCT01352117.

Disparities in Kaposi sarcoma incidence and survival in the United States: 2000-2013.

OBJECTIVE: Geographic and racial disparities may contribute to variation in the incidence and outcomes of HIV-associated cancers in the United States. METHOD: Using the Surveillance, Epidemiology, and End Results (SEER) database, we analyzed Kaposi sarcoma (KS) incidence and survival by race and geographic region during the combined antiretroviral therapy era. Reported cases of KS in men from 2000 to 2013 were obtained from 17 SEER cancer registries. Overall and age-standardized KS incidence rates were calculated and stratified by race and geographic region. We evaluated incidence trends using joinpoint analyses and calculated adjusted hazard ratios (aHR) for overall and KS-specific mortality using multivariable Cox proportional hazards models. RESULTS: Of 4,455 KS cases identified in men younger than 55 years (median age 40 years), the annual percent change (APC) for KS incidence significantly decreased for white men between 2001 and 2013 (APC -4.52, p = 0.02). The APC for AA men demonstrated a non-significant decrease from 2000-2013 (APC -1.84, p = 0.09). Among AA men in the South, however, APC has significantly increased between 2000 and 2013 (+3.0, p = 0.03). In addition, compared with white men diagnosed with KS during the same time period, AA men were also more likely to die from all causes and KS cancer-specific causes (aHR 1.52, 95% CI 1.34-1.72, aHR 1.49, 95% CI 1.30-1.72 respectively). CONCLUSION: Although overall KS incidence has decreased in the U.S., geographic and racial disparities in KS incidence and survival exist.

Risk of Cancer among Commercially Insured HIV-Infected Adults on Antiretroviral Therapy.

The objective of this study was to explore the cancer incidence rates among HIV-infected persons with commercial insurance who were on antiretroviral therapy and compare them with those rates in the general population. Paid health insurance claims for 63,221 individuals 18 years or older, with at least one claim with a diagnostic code for HIV and at least one filled prescription for an antiretroviral medication between January 1, 2006, and September 30, 2012, were obtained from the LifeLink® Health Plan Claims Database. The expected number of cancer cases in the general population for each gender-age group (<30, 30-39, 40-49, 50-59, and >60 years) was estimated using incidence rates from the Surveillance Epidemiology and End Results (SEER) program. Standardized incidence ratios (SIRs) were estimated using their 95% confidence intervals (CIs). Compared to the general population, incidence rates for HIV-infected adults were elevated (SIR, 95% CI) for Kaposi sarcoma (46.08; 38.74-48.94), non-Hodgkin lymphoma (4.22; 3.63-4.45), Hodgkin lymphoma (9.83; 7.45-10.84), and anal cancer (30.54; 25.62-32.46) and lower for colorectal cancer (0.69; 0.52-0.76), lung cancer (0.70; 0.54, 0.77), and prostate cancer (0.54; 0.45-0.58). Commercially insured, treated HIV-infected adults had elevated rates for infection-related cancers, but not for common non-AIDS defining cancers.

Brief Report: A Phase 1b/Pharmacokinetic Trial of PTC299, a Novel PostTranscriptional VEGF Inhibitor, for AIDS-Related Kaposi's Sarcoma: AIDS Malignancy Consortium Trial 059.

Vascular endothelial growth factor (VEGF) plays an important role in Kaposi's sarcoma (KS). We administered PTC299, a post-transcriptional inhibitor of pathogenic VEGF, to persons with HIV-related KS. Seventeen participants received 3 different doses of PTC299. Adverse events typically observed with VEGF inhibition were absent. Three participants had partial tumor responses and 11 had stable disease. There were no differences in exposure to PTC299 by antiretroviral regimen. Serum VEGF, but not KS-associated herpesvirus DNA, decreased on treatment. Given redundancies in the VEGF feedback loop, future trials should consider combining PTC299 with agents that inhibit different pathways implicated in KS and KS-associated herpesvirus proliferation.

Challenges in the detection, prevention, and treatment of HIV-associated malignancies in low- and middle-income countries in Africa.

Cancers associated with immunosuppression and infections have long been recognized as a major complication of HIV/AIDS. More recently, persons living with HIV are increasingly diagnosed with a wider spectrum of HIV-associated malignancies (HIVAM) as they live longer on combination antiretroviral therapy. This has spurred research to characterize the epidemiology and determine the optimal management of HIVAM with a focus on low-and middle-income countries (LMICs). Given background coinfections, environmental exposures, host genetic profiles, antiretroviral therapy usage, and varying capacities for early diagnosis and treatment, one can expect the biology of cancers in HIV-infected persons in LMICs to have a significant impact on chronic HIV care, as is now the case in high-income countries. Thus, new strategies must be developed to effectively prevent, diagnose, and treat HIVAM in LMICs; provide physical/clinical infrastructures; train the cancer and HIV workforce; and expand research capacity-particularly given the challenges posed by the limitations on available transportation and financial resources and the population's general rural concentration. Opportunities exist to extend resources supported by the President's Emergency Plan for AIDS Relief and the Global Fund to Fight AIDS, Tuberculosis, and Malaria to improve the health-care infrastructure and train the personnel required to prevent and manage cancers in persons living with HIV. These HIV chronic care infrastructures could also serve cancer patients regardless of their HIV status, facilitating long-term care and treatment for persons who do not live near cancer centers, so that they receive the same degree of care as those receiving chronic HIV care today.

Phase II trial of imatinib in AIDS-associated Kaposi's sarcoma: AIDS Malignancy Consortium Protocol 042.

PURPOSE: Kaposi's sarcoma (KS) is a disease of multifocal vascular proliferation that requires infection with KS herpes virus (KSHV/HHV-8). Activation of the c-kit and platelet-derived growth factor (PDGF) receptors by autocrine/paracrine mechanisms follows endothelial cell KSHV infection. In a pilot study, imatinib, a c-kit/PDGF-receptor inhibitor, induced partial regression of AIDS-associated KS (AIDS-KS) in five of 10 patients. PATIENTS AND METHODS: This multicenter phase II study was designed to estimate the response rate to imatinib in AIDS-KS. Secondary objectives included investigation of predictors of response and imatinib pharmacokinetics in patients on antiretrovirals. Patients received imatinib 400 mg/day by mouth for up to 12 months with dose escalation up to 600 mg/day at 3 months if their disease was stable. RESULTS: Thirty patients were treated at 12 AIDS Malignancy Consortium sites. Ten patients (33.3%) achieved partial response, six (20%) had stable disease, and seven (23.3%) exhibited KS progression. Nine patients completed 52 weeks of imatinib therapy. The median treatment duration was 22.5 weeks. Only five patients (16.7%) discontinued therapy owing to adverse events. Antiretroviral regimens did not significantly alter imatinib metabolism. Activating mutations in PDGF-R and c-kit were not found at baseline or at disease progression. We found no correlation with response with changes in any of the candidate cytokines. CONCLUSION: Imatinib has activity in AIDS-KS. Pharmacokinetic interactions with antiretroviral drugs did not correlate with toxicity. Thirty percent of patients showed long-term clinical benefit and remained on imatinib for the entire year. These results suggest imatinib is well tolerated and may be an alternative therapy for some patients with AIDS-KS.

CpG methylation as a tool to characterize cell-free Kaposi sarcoma herpesvirus DNA.

We studied the presence of Kaposi sarcoma herpesvirus sequences in cell-free DNA (cfDNA) isolated from the blood of patients with AIDS-related Kaposi sarcoma (KS) and primary effusion lymphoma (PEL). The use of paramagnetic beads linked to methyl-CpG binding domain protein allowed separation of virion and cell-derived DNA. Only virion DNA was detected in the blood of KS patients, whereas cell-derived DNA was detected in a patient with AIDS-related PEL. The difference in the origins of cfDNA in these settings may in part reflect very different proliferative indices in KS and PEL tumor tissue.

Rapamycin with antiretroviral therapy in AIDS-associated Kaposi sarcoma: an AIDS Malignancy Consortium study.

PURPOSE: The mammalian target of rapamycin is activated in Kaposi sarcoma (KS) and its inhibitor, rapamycin, has induced KS regression in transplant-associated KS. This study aimed to evaluate rapamycin's safety and toxicity in HIV-infected individuals with KS receiving antiretroviral therapy (ART), investigate rapamycin interactions with both protease inhibitor (PI)-containing and nonnucleoside reverse transcriptase inhibitor (NNRTI)-containing ART regimens, and assess clinical and biological endpoints including KS response and mammalian target of rapamycin-dependent signaling. METHODS: Seven participants, 4 on PI-based and 3 on NNRTI-based ART, had rapamycin titrated to achieve trough concentrations of 5-10 ng/mL. Patients were monitored for safety and KS response. KS biopsies were evaluated for changes in phosphoribosomal S6 protein, and phospho-Akt expression. Interleukin 6 and vascular endothelial growth factor levels, HIV and KS-associated herpesvirus viral loads, and CD4 counts were monitored. RESULTS: Despite pharmacokinetic interactions resulting in >200-fold differences in cumulative weekly rapamycin doses between participants on PI-containing and NNRTI-containing regimens, treatment was well tolerated. There were no significant changes in viral loads or cytokine levels; modest initial decreases in CD4 counts occurred in some patients. Three participants, all on PI-containing regimens and with higher rapamycin exposure, showed partial KS responses. Three of 4 subjects whose biopsies were studied at ≥day 50 showed decreased phosphoribosomal S6 protein staining. CONCLUSIONS: Rapamycin seems safe in HIV-infected individuals with KS and can, in some cases, induce tumor regression and affect its molecular targets. Significant pharmacokinetic interactions require careful titration to achieve target drug trough concentrations but may be exploited to achieve therapeutic benefit.