Pembrolizumab induces HIV latency reversal in people living with HIV and cancer on antiretroviral therapy.

In people living with HIV (PLWH) on antiretroviral therapy (ART), virus persists in a latent form where there is minimal transcription or protein expression. Latently infected cells are a major barrier to curing HIV. Increasing HIV transcription and viral production in latently infected cells could facilitate immune recognition and reduce the pool of infected cells that persist on ART. Given that programmed cell death protein 1 (PD-1) expressing CD4+ T cells are preferentially infected with HIV in PLWH on ART, we aimed to determine whether administration of antibodies targeting PD-1 would reverse HIV latency in vivo. We therefore evaluated the impact of intravenous administration of pembrolizumab every 3 weeks on HIV latency in 32 PLWH and cancer on ART. After the first infusion of anti-PD-1, we observed a median 1.32-fold increase in unspliced HIV RNA and 1.61-fold increase in unspliced RNA:DNA ratio in sorted blood CD4+ T cells compared to baseline. We also observed a 1.65-fold increase in plasma HIV RNA. The frequency of CD4+ T cells with inducible virus evaluated using the tat/rev limiting dilution assay was higher after 6 cycles compared to baseline. Phylogenetic analyses of HIV env sequences in a participant who developed low concentrations of HIV viremia after 6 cycles of pembrolizumab did not demonstrate clonal expansion of HIV-infected cells. These data are consistent with anti-PD-1 being able to reverse HIV latency in vivo and support the rationale for combining anti-PD-1 with other interventions to reduce the HIV reservoir.

Use of advanced PET-volume metrics predicts risk of local recurrence and overall survival in anal cancer.

OBJECTIVE: Anal cancer is an uncommon malignancy with the primary treatment for localized disease being concurrent radiation and chemotherapy. Pre-treatment PET/CT is useful for target delineation, with minimal exploration of its use in prognostication. In the post-treatment setting there is growing evidence for advanced PET metrics in assessment of treatment response, and early identification of recurrence essential for successful salvage, however this data is limited to small series. METHODS: Patient with non-metastatic anal cancer from a single institution were retrospectively reviewed for receipt of pre- and post-treatment PET/CTs. PET data was co-registered with radiation therapy planning CT scans for precise longitudinal assessment of advanced PET metrics including SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), for assessment with treatment outcomes. Treatment outcomes included local recurrence (LR), progression free survival (PFS), and overall survival (OS), as defined from the completed radiation therapy to the time of the event. Cox proportional hazard modeling with inverse probability weighting (IPW) using the propensity score based on age, BMI, T-stage, and radiation therapy dose were utilized for assessment of these metrics. RESULTS: From 2008 to 2017 there were 72 patients who had pre-treatment PET/CT, 61 (85%) had a single follow up PET/CT, and 35 (49%) had two follow up PET/CTs. The median clinical follow-up time was 25 months (IQR: 13-52) with a median imaging follow up time of 16 months (IQR: 7-29). On pre-treatment PET/CT higher MTV2.5 and TLG were significantly associated with higher risk of local recurrence (HR 1.11, 95% CI: 1.06-1.16, p<0.001; and HR 1.12, 95% CI: 1.05-1.19, p<0.001), and worse PFS (HR 1.09, 95% CI: 1.04-1.13, p<0.001; and HR 1.09, 95% CI: 1.03-1.12, p = 0.003) and OS (HR 1.09, 95% CI: 1.04-1.16, p = 0.001; and HR 1.11, 95% CI: 1.04-1.20, p = 0.004). IPW-adjusted pre-treatment PET/CT showed higher MTV2.5 (HR 1.09, 95% CI: 1.02-1.17, p = 0.012) and TLG (HR 1.10, 95% CI: 1.00-1.20, p = 0.048) were significantly associated with worse PFS, and post-treatment MTV2.5 was borderline significant (HR 1.16, 95% CI: 1.00-1.35, p = 0.052). CONCLUSION: Advanced PET metrics, including higher MTV2.5 and TLG, in the pre-treatment and post-treatment setting are significantly associated with elevated rates of local recurrence, and worse PFS and OS. This adds to the growing body of literature that PET/CT for patient with ASCC should be considered for prognostication, and additionally is a useful tool for consideration of early salvage or clinical trial of adjuvant therapies.

Factors Impacting Differential Outcomes in the Definitive Radiation Treatment of Anal Cancer Between HIV-Positive and HIV-Negative Patients.

BACKGROUND: Anal squamous cell carcinoma (ASCC) is uncommon, yet seen more frequently in the setting of the human immunodeficiency virus (HIV). Chemoradiotherapy is the definitive modality of treatment for patients with ASCC; this study examines factors impacting clinical outcomes in a large cohort of HIV-positive and HIV-negative patients. METHODS: A retrospective review was conducted of patients treated for nonmetastatic ASCC at a single institution between 2005 and 2018. Freedom from local recurrence (FFLR), freedom from distant metastasis, and overall survival (OS) were calculated using the Kaplan-Meier method, and univariate and multivariate analysis were performed using the Cox proportional hazards model. RESULTS: During the study period, 111 patients initiated definitive treatment for ASCC. Median age of the entire cohort was 56.7 years (interquartile range, 51.5-63.5), with 52 patients (46.8%) being HIV-positive. At median follow-up of 28.0 months, the 2- and 5-year FFLR were 78.2% (95% confidence interval [CI], 70.4-87.0) and 74.6% (95% CI, 65.8-84.5), respectively. Multivariate analysis revealed time from diagnosis to treatment initiation (median, 8 weeks; hazard ratio, 1.06; 95% CI, 1.03-1.10) to be significantly associated with worse FFLR and OS. HIV-positive patients had a trend toward worse FFLR (log-ranked p = .06). For HIV-positive patients with post-treatment CD4 less than 150 cells per mm3 , there was significantly worse OS (log-ranked p = .015). CONCLUSION: A trend toward worse FFLR was seen in HIV-positive patients, despite similar baseline disease characteristics as HIV-negative patients. Worse FFLR and OS was significantly associated with increased time from diagnosis to treatment initiation. Poorer OS was seen in HIV-positive patients with a post-treatment CD4 count less than 150 cells per mm3 . IMPLICATIONS FOR PRACTICE: Human immunodeficiency virus (HIV)-positive patients with anal squamous cell carcinoma can represent a difficult clinical scenario. Definitive radiation with concurrent chemotherapy is highly effective but can result in significant toxicity and a decrease in CD4 count that could predispose to HIV-related complications. As HIV-positive patients have largely been excluded from prospective clinical trials, this study seeks to provide greater understanding of their outcomes with radiation therapy, potential predictors of worse local control and overall survival, and those most at risk after completion of treatment.

Assessment of the Safety of Pembrolizumab in Patients With HIV and Advanced Cancer-A Phase 1 Study.

IMPORTANCE: Anti-PD-1 (anti-programmed cell death 1) and anti-PD-L1 (anti-programmed cell death ligand 1) regimens are preferred therapies for many cancers, including cancers associated with HIV. However, patients with HIV were excluded from most registered trials. OBJECTIVE: The primary objective was to evaluate the safety of pembrolizumab in people with HIV and advanced cancer; the secondary objective was to evaluate tumor responses. DESIGN, SETTING, AND PARTICIPANTS: Open-label, nonrandomized, phase 1 multicenter study conducted at 7 Cancer Immunotherapy Trials Network sites. Patients with HIV and advanced cancer as well as a CD4 count greater than or equal to 100 cells/µL, antiretroviral therapy (ART) for 4 or more weeks, and an HIV viral load of less than 200 copies/mL were eligible. Exclusion criteria included uncontrolled hepatitis B or C infection, active immunosuppressive therapy, or a history of autoimmune disease requiring systemic therapy. INTERVENTIONS: Pembrolizumab, 200 mg, administered intravenously every 3 weeks for up to 35 doses in 3 CD4 count-defined cohorts. Participants continued ART. MAIN OUTCOMES AND MEASURES: Safety and tolerability were assessed using current NCI Common Terminology Criteria for Adverse Events. Immune-related adverse events grade 2 or higher were considered immune-related events of clinical interest (irECI). Tumor responses were evaluated using standard tumor-specific criteria. RESULTS: Thirty participants (28 men and 2 women; median [range] age, 57 [39-77] years) were enrolled from April 2016 through March 2018; 6 had Kaposi sarcoma (KS), 5 had non-Hodgkin lymphoma (NHL), and 19 had non-AIDS-defining cancers. Safety was observed over 183 cycles of treatment with pembrolizumab. Most treatment-emergent adverse events at least possibly attributed to pembrolizumab were grade 1 or 2 (n = 22), and 20% (n = 6) were grade 3. The irECI included hypothyroidism (6 participants), pneumonitis (3 participants), rash (2 participants), an elevated aminotransferase/alanine aminotransferase level (1 participant), and a musculoskeletal event (1 participant). One participant with pretreatment KS herpesvirus (KSHV) viremia developed a polyclonal KSHV-associated B-cell lymphoproliferation and died. HIV was controlled in all participants. Increases in CD4 count were not statistically significant (median increase, 19 cells/µL; P = .18). Best tumor responses included complete response (lung, 1 patient), partial response (NHL, 2 patients), stable disease for 24 weeks or more (KS, 2 patients), stable disease for less than 24 weeks (15 patients), and progressive disease (8 patients); 2 patients were not evaluable. CONCLUSIONS AND RELEVANCE: Pembrolizumab has acceptable safety in patients with cancer, HIV treated with ART, and a CD4+ T-cell count of greater than 100 cells/µL but may be associated with KSHV-associated B-cell lymphoproliferation. Clinical benefit was noted in lung cancer, NHL, and KS. Anti-PD-1 therapy is appropriate for US Food and Drug Administration-approved indications and clinical trials in this population. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02595866.

Leptospirosis with transient paraparesis and thrombocytopenia: a case report.

Leptospirosis is the most widespread zoonosis in the world. We present an unusual case of leptospirosis in a 44-year-old man with severe thrombocytopenia and transient paraparesis. The diagnosis of leptospirosis was confirmed by blood nested polymerase chain reaction, seroconversion of Leptospira IgM and the microscopic agglutination test. Nerve conduction studies were suggestive of early polyneuropathy involving the right peroneal nerve and bilateral sural nerves. Peripheral nerve palsy is a potential clinical feature of leptospirosis.