Therapeutic activity of retroviral replicating vector-mediated gene therapy in combination with anti-PD-1 antibody in a murine pancreatic cancer model.

Toca 511, a tumor-selective retroviral replicating vector encoding the yeast cytosine deaminase (yCD) gene, exerts direct antitumor effects through intratumoral prodrug 5-fluorocytosine (5-FC) conversion to active drug 5-fluorouracil by yCD, and has demonstrated therapeutic efficacy in preclinical and clinical trials of various cancers. Toca 511/5-FC treatment may also induce antitumor immunity. Here, we first examined antitumor immune responses activated by Toca 511/5-FC treatment in an immunocompetent murine pancreatic cancer model. We then evaluated the therapeutic effects achieved in combination with anti-programmed cell death protein 1 antibody. In the bilateral subcutaneous tumor model, as compared with the control group, enhanced CD8+ T-cell-mediated cytotoxicity and increased T-cell infiltration in Toca 511-untransduced contralateral tumors were observed. Furthermore, the expression levels of T-cell co-inhibitory receptors on CD8+ T-cells increased during treatment. In the bilateral subcutaneous tumor model, combination therapy showed significantly stronger tumor growth inhibition than that achieved with either monotherapy. In an orthotopic tumor and peritoneal dissemination model, the combination therapy resulted in complete regression in both transduced orthotopic tumors and untransduced peritoneal dissemination. Thus, Toca 511/5-FC treatment induced a systemic antitumor immune response, and the combination therapy could be a promising clinical strategy for treating metastatic pancreatic cancer.

Disseminated phaeohyphomycosis due to Cladophialophora bantiana in an immunocompetent child.

A 3-year-old boy presented with acute headache, vomiting and right focal clonic seizures without history of fever, joint pain or altered sensorium. Neuroimaging showed multifocal contrast enhancing lesions with significant perilesional edema. CECT chest and abdomen showed multiple variable sized nodules in the lungs and hypodense lesion in liver with mesenteric lymphadenopathy. There was persistent eosinophilia with maximum upto 35 %. Liver biopsy and brain biopsy revealed Cladophialophora bantiana. He was treated with IV liposomal amphotericin and voriconazole for 6 weeks with repeat neuroimaging showing more than 50 % resolution of the intracranial lesions. He was transitioned to oral combination of flucytosine and voriconazole. At 14 months follow-up, he remained symptom free with complete radiological resolution of the lesions and no eosinophilia. High suspicion, an aggressive approach in obtaining microbiological diagnosis and timely combination antifungal therapy may give satisfactory outcome without surgery.

Features of cryptococcosis among 652 HIV-seronegative individuals in France: a cross-sectional observational study (2005-2020).

OBJECTIVES: We aimed to describe features and outcomes of cryptococcosis among HIV-seronegative individuals in a large surveillance network for cryptococcosis in France. METHODS: We included incident cases of cryptococcosis in HIV-seronegative individuals from 2005 to 2020. We compared patient characteristics, disease presentations, cryptococcal antigen results, and induction antifungal treatments according to underlying disease. We examined factors associated with 90-day mortality. Among patients with disseminated infections, we investigated whether receipt of flucytosine and polyene combination was associated with lower mortality. RESULTS: Among 652 individuals, 209 (32.1%) had malignancy, 130 (19.9%) were solid-organ transplant recipients, 204 (31.3%) had other immunocompromising conditions, and 109 (16.7%) had no reported underlying factor. The commonest presentations were disseminated infections (63.3%, 413/652) and isolated pulmonary infections (25.3%, 165/652). Solid-organ transplant patients were most likely to have disseminated infections and a positive serum cryptococcal antigen result. Patients with malignancy were older and less likely to receive a flucytosine-containing regimen for disseminated infections than others (58.7%, 78/133 vs. 73.2%, 194/265; p 0.029). The crude 90-day case-fatality ratio was 27.2% (95% CI, 23.5%-31.1%). Age ≥60 years (aOR: 2.75 [1.78-4.26]; p < 0.001), meningitis/fungaemia (aOR: 4.79 [1.80-12.7]; p 0.002), and malignancy (aOR: 2.4 [1.14-5.07]; p 0.02) were associated with higher 90-day mortality. Receipt of flucytosine and polyene combination was associated with lower 90-day mortality (aOR: 0.40 [0.23-0.71]; p 0.002) in multivariable analysis and inverse probability of treatment weighted analysis (aOR: 0.45 [0.25-0.80]; p 0.006). DISCUSSION: HIV-seronegative individuals with cryptococcosis comprise a wide range of underlying conditions with different presentations and outcomes, requiring a tailored approach to diagnosis and management.

HIV-associated disseminated cryptococcosis-An unusual clinical and diagnostic picture with successful cure by single dose liposomal amphotericin B treatment.

BACKGROUND: Cryptococcosis is an invasive, opportunistic fungal infection seen especially in human immunodeficiency virus (HIV) infected patients. Cryptococcal meningitis (CM) is the second leading cause of mortality in HIV patients. We report a case of disseminated cryptococcosis presenting with altered mental status in a newly diagnosed HIV infection. METHODS AND RESULTS: A 50-year-old with a short history of altered mental sensorium and a history of low-grade fever and weight loss for few months presented at a tertiary care hospital in North India. He was detected positive for HIV-1. Cryptococcal antigen (CRAG) was positive in Cerebrospinal fluid (CSF), and negative in serum. The fungal culture in CSF was sterile while the fungal blood culture grew Cryptococcus neoformans. The patient was treated with single high-dose Liposomal Amphotericin B (LAmB) therapy followed by Fluconazole and Flucytosine for the next two weeks followed by fluconazole daily for consolidation and maintenance therapy. Antiretroviral therapy (ART) was started 4 weeks after induction therapy. After 6 months, the patient is doing fine. CONCLUSION: Single dose LAmB along with the backbone of fluconazole and flucytosine appears promising in disseminated cryptococcal infection in HIV-infected individuals.

Voriconazole plus flucytosine is not superior to amphotericin B deoxycholate plus flucytosine as an induction regimen for cryptococcal meningitis treatment.

BACKGROUND: The efficacy and side effects of voriconazole plus 5-flucytosine (Vori + 5-FC) versus amphotericin B deoxycholate plus 5-flucytosine (AmBd + 5-FC) as an induction treatment for cryptococcal meningitis are unknown. METHODS: Forty-seven patients treated with Vori + 5-FC and 92 patients treated with AmBd + 5-FC were included in the current study after propensity score matching (PSM) at a ratio of 1:2. Two-week laboratory test results and 90-day mortality were compared between the two groups. RESULTS: After 2 weeks of induction treatment, the CSF Cryptococcus sterile culture rate was 57.1% in the Vori + 5-FC group and 76.5% in the AmBd + 5-FC group (p = .026). No difference was found in the normalization of CSF indicators (glucose, total protein, intracranial pressure and India ink sterile rate) between the two groups. Both the Vori + 5FC regimen and AmBd + 5-FC regimen obviously decreased haemoglobin concentrations, platelet counts and serum potassium levels (all p ≤ .010). Notably, the Vori + 5FC regimen did not influence serum creatinine levels (p = .263), while AmBd + 5FC increased serum creatinine levels (p = .019) after 2-week induction treatment. The Vori + 5-FC group and AmBd + 5-FC group had similar 90-day cumulative survival rates (89.9% vs. 87.8%, p = .926). CONCLUSION: The Vori + 5-FC regimen was associated with low 2-week CSF sterile culture and was not superior to AmBd + 5-FC as induction therapy in terms of the 90-day cumulative survival rate of CM patients.

Synergistic effect of the verapamil and amphotericin B against Cryptococcus neoformans.

Cryptococcus neoformans is an encapsulated yeast that can cause cryptococcosis and cryptococcal meningitis, which conventional treatment involves antifungal drugs such as polyenes, flucytosine, azoles, and their combinations. However, the high cost, toxicity, and increase in fungi resistance to antifungal agents stimulate the search for therapeutic strategies such as drug repurposing and combination therapy. This study evaluated the activity of the antihypertensive verapamil (VEH) alone and combined with amphotericin B (AmB) against C. neoformans. VEH exhibited antifungal activity against C. neoformans with minimum inhibitory concentration and minimum fungicidal concentration of 118 µg per mL. The combination of VEH and AmB exhibited synergism, reducing at least eightfold both drugs' concentrations. Moreover, the combination decreased the size and glucuronoxylomannnan content of C. neoformans capsule. However, no difference was observed in ergosterol levels of C. neoformans after treatment with VEH and AmB in combination. Altogether, VEH in combination with AmB exhibits potential as a candidate as for the development of anti-cryptococcal drug.

Palmitoylethanolamide shows limited efficacy in controlling cerebral cryptococcosis in vivo.

Cryptococcus neoformans (Cn) is an encapsulated neurotropic fungal pathogen and the causative agent of cryptococcal meningoencephalitis (CME) in humans. Recommended treatment for CME is Amphotericin B (AmpB) and 5-fluorocytosine (5-FC). Though effective, AmpB has displayed numerous adverse side effects due to its potency and nephrotoxicity, prompting investigation into alternative treatments. Palmitoylethanolamide (PEA) is an immunomodulatory compound capable of promoting neuroprotection and reducing inflammation. To investigate the efficacy of PEA as a therapeutic alternative for CME, we intracerebrally infected mice with Cn and treated them with PEA or AmpB alone or in combination. Our results demonstrate that PEA alone does not significantly prolong survival nor reduce fungal burden, but when combined with AmpB, PEA exerts an additive effect and promotes both survivability and fungal clearance. However, we compared this combination to traditional AmpB and 5-FC treatment in a survivability study and observed lower efficacy. Overall, our study revealed that PEA alone is not effective as an antifungal agent in the treatment of CME. Importantly, we describe the therapeutic capability of PEA in the context of Cn infection and show that its immunomodulatory properties may confer limited protection when combined with an effective fungicidal agent.

Searching for new antifungals for the treatment of cryptococcosis.

There is a consensus that the antifungal repertoire for the treatment of cryptococcal infections is limited. Standard treatment involves the administration of an antifungal drug derived from natural sources (i.e., amphotericin B) and two other drugs developed synthetically (i.e., flucytosine and fluconazole). Despite treatment, the mortality rates associated with fungal cryptococcosis are high. Amphotericin B and flucytosine are toxic, require intravenous administration, and are usually unavailable in low-income countries because of their high cost. However, fluconazole is cost-effective, widely available, and harmless with regard to its side effects. However, fluconazole is a fungistatic agent that has contributed considerably to the increase in fungal resistance and frequent relapses in patients with cryptococcal meningitis. Therefore, there is an unquestionable need to identify new alternatives or adjuvants to conventional drugs for the treatment of cryptococcosis. A potential antifungal agent should be able to kill cryptococci and "bypass" the virulence mechanism of the yeast. Furthermore, it should have fungicidal action, low toxicity, high selectivity, easily penetrate the central nervous system, and widely available. In this review, we describe cryptococcosis, its conventional therapy, and failures arising from the use of drugs traditionally considered to be the reference standard. Additionally, we present the approaches used for the discovery of new drugs to counteract cryptococcosis, ranging from the conventional screening of natural products to the inclusion of structural modifications to optimize anticryptococcal activity, as well as drug repositioning and combined therapies.

Systemic lupus erythematosus complicated with cryptococcal meningitis: A case report.

RATIONALE: Patients with systemic lupus erythematosus (SLE) complicated with cryptococcal meningitis (CM) are easy to be misdiagnosed as neuropsychiatric lupus or tuberculous meningitis due to the lack of specificity of clinical symptoms, which may delay treatment. Through this case, we considered early improvement of India ink stain of cerebrospinal fluid (CSF) and metagenomic next generation sequences to determine whether there is microbial infection, and gave the idea of empirical anti-infection therapy, so as to make early diagnosis and slow down the progression of the disease. PATIENT CONCERNS: We report the case of a 40-year-old female with SLE for 10 years. Five days ago she came down with a fever and a headache. DIAGNOSIS, INTERVENTIONS, AND OUTCOMES: India ink stain of CSF in patients with SLE shows Cryptococcus neoformans growth. Combined with imaging findings, the patient was diagnosed with CM. The patient improved after 3 weeks of antifungal therapy with amphotericin B 42 mg/d and flucytosine 6000 mg/d. LESSONS: The possibility of CM should be considered when SLE patients have sudden headache and fever. India ink stain of CSF and metagenomic next generation sequences should be actively improved in the early stage of the disease to identify whether there is microbial infection, and early empirical anti-infection treatment should be given to reduce mortality.

Higher Dose Oral Fluconazole for the Treatment of AIDS-related Cryptococcal Meningitis (HIFLAC)-report of A5225, a multicentre, phase I/II, two-stage, dose-finding, safety, tolerability and efficacy randomised, amphotericin B-controlled trial of the AIDS Clinical Trials Group.

BACKGROUND: The WHO recommended 1200mg/day of fluconazole (FCZ) in the induction phase of cryptococcal meningitis (CM) in HIV prior to 2018 in regions where amphotericin-B (AMB) was unavailable. A 2-stage AMB-controlled, dose-escalation study to determine the maximum tolerated dose and the safety/efficacy of an induction-consolidation strategy of higher doses FCZ (1200mg-2000mg/day), adjusted for weight and renal function (eGFR)in adults with CM was undertaken. METHODS: In Stage-1, three induction doses of FCZ (1200mg/day, 1600mg/day and 2000mg/day) were tested in sequential cohortsand compared with AMB in a 3:1 ratio. A particular dose was not tested in Stage 2 if there were significant predetermined safety or efficacy concerns. In Stage-2, the 1200mg dose was excluded per protocol because of increased mortality, and participants were randomised to 1600mg, 2000mg FCZ or AMB in a 1:1:1 ratio. FINDINGS: One hundred and sixty eight participants were enrolled with 48, 50, and 48 in the AMB, 1600mg and 2000mg cohorts. The Kaplan Meier proportion for mortality (90% CI) at 10 and 24 weeks for AMB was 17% (10, 29) and 24% (15, 37), compared to 20% (12, 32) and 30% (20, 43) for 1600mg, and 33% (23, 46) and 38% (27, 51) for 2000mg/day FCZ. With the exception of a higher incidence of gastrointestinal side effects in the 2000mg cohort, both induction doses of FCZ were safe and well tolerated. There were no life-threatening changes in electrocardiogram QTc which were similar across all doses of FCZ and AMB. The median (IQR) change in log10 cryptoccal colony forming units (CFU) from week 0 to week 2 was -8(-4.1,-1.9) for AMB; -2.5(-4.0, -1.4) for 1600mg FCZ and -8 (-3.2, -1.0) for 2000mg FCZ. The proportion (90% CI) CSF CM negative at 10 weeks was 81%(71,90) for AMB; 56%(45,69) for 1600mg FCZ and 60%(49,73) for 2000mg FCZ. INTERPRETATION: Induction phase weight and renal-adjusted doses of 1600mg and 2000mg/day FCZ for CM were safe and well tolerated except for increased GI side effects in the 2000mg/day dose, and had similar times to achieve CSF sterilization, but took significantly longer than AMB. The WHO recommended 1200mg FCZ was associated with a high mortality. While not statistically significant, mortality was numerically lower in the AMB compared to 1600mg and 2000mg FCZ These data make a case for a phase 3 study of higher doses of FZC.

How Applicable Is the Single-Dose AMBITION Regimen for Human Immunodeficiency Virus-Associated Cryptococcal Meningitis to High-Income Settings?

The AmBisome Therapy Induction Optimization (AMBITION-cm) trial, conducted in eastern and southern Africa, showed that a single, high dose (10 mg/kg) of liposomal amphotericin B, given with an oral backbone of fluconazole and flucytosine, was noninferior to the World Health Organization (WHO)-recommended regimen of 7 days of amphotericin B deoxycholate plus flucytosine for treatment of human immunodeficiency virus (HIV)-associated cryptococcal meningitis and has been incorporated into WHO treatment guidelines. We believe that the trial also has important implications for the treatment of HIV-associated cryptococcal meningitis in high-income settings. We advance the arguments, supported by evidence where available, that the AMBITION-cm trial regimen is likely to be as fungicidal as the currently recommended 14-day liposomal amphotericin-based treatments, better tolerated with fewer adverse effects, and confer significant economic and practical benefits and, therefore, should be included as a treatment option in guidance for HIV-associated cryptococcal treatment in high-income settings.

An updated systematic review of HIV-associated cryptococcal meningitis treatment strategies.

BACKGROUND: The purpose of this systematic review is to provide updated evidence on the preferred induction therapy for the treatment of HIV-associated cryptococcal meningitis considering the most recent evidence available in order to inform the need for updates to WHO guidelines. METHODS: We searched Medline via PubMed, EMBASE, the Cochrane Library and clinicaltrials.gov for published or completed randomized clinical trials that evaluated induction treatment of first episode HIV-associated cryptococcal meningitis from 9 July 2018 (date of last search) to 1 September 2021. RESULTS: One randomized clinical trial of 844 people with HIV-associated cryptococcal meningitis met the inclusion criteria. Participants were randomized to: (1) amphotericin deoxycholate for 7 days, with flucytosine and fluconazole (control); or (2) a single dose of liposomal amphotericin 10 mg/kg with flucytosine and fluconazole (intervention). In the intention-to-treat analysis, 10-week mortality was 24.8% [95% confidence interval (CI): 20.7-29.3%] in the single-dose liposomal amphotericin group compared with 28.7% (95% CI: 24.4-33.4%) in the control group. The absolute difference in 10-week mortality was -3.9% with an upper one-sided 95% CI of 1.2%, within the 10% pre-specified non-inferiority margin. Fewer participants had grade 3 and 4 adverse events in the intervention arm compared with the control arm (50.0% vs. 62.3%, p < 0.001). CONCLUSIONS: In the single study included in this systematic review, single high-dose liposomal amphotericin B with flucytosine and fluconazole was non-inferior to the WHO-recommended standard of care induction therapy for HIV-associated cryptococcal meningitis, with significantly fewer adverse events.

The fungal expel of 5-fluorocytosine derived fluoropyrimidines mitigates its antifungal activity and generates a cytotoxic environment.

Invasive aspergillosis remains one of the most devastating fungal diseases and is predominantly linked to infections caused by the opportunistic human mold pathogen Aspergillus fumigatus. Major treatment regimens for the disease comprise the administration of antifungals belonging to the azole, polyene and echinocandin drug class. The prodrug 5-fluorocytosine (5FC), which is the only representative of a fourth class, the nucleobase analogs, shows unsatisfactory in vitro activities and is barely used for the treatment of aspergillosis. The main route of 5FC activation in A. fumigatus comprises its deamination into 5-fluorouracil (5FU) by FcyA, which is followed by Uprt-mediated 5FU phosphoribosylation into 5-fluorouridine monophosphate (5FUMP). In this study, we characterized and examined the role of a metabolic bypass that generates this nucleotide via 5-fluorouridine (5FUR) through uridine phosphorylase and uridine kinase activities. Resistance profiling of mutants lacking distinct pyrimidine salvage activities suggested a minor contribution of the alternative route in 5FUMP formation. We further analyzed the contribution of drug efflux in 5FC tolerance and found that A. fumigatus cells exposed to 5FC reduce intracellular fluoropyrimidine levels through their export into the environment. This release, which was particularly high in mutants lacking Uprt, generates a toxic environment for cytosine deaminase lacking mutants as well as mammalian cells. Employing the broad-spectrum fungal efflux pump inhibitor clorgyline, we demonstrate synergistic properties of this compound in combination with 5FC, 5FU as well as 5FUR.

Cryptococcus neoformans Presenting as a Lung Mass in an Immunocompromised Patient.

BACKGROUND Pulmonary cryptococcosis is an uncommon infection mainly affecting immunocompromised individuals. Presentation of cryptococcal disease ranges from asymptomatic pulmonary colonization to severe pneumonia. It can progress to acute respiratory failure and life-threatening meningoencephalitis. CASE REPORT A 55-year-old woman with a history of a kidney transplant, on immunosuppressive therapy, presented to the hospital with persistent low-grade fever, headache, weight loss, and fatigue for 2 weeks. On arrival, she was tachycardic, normotensive, and saturating 99% on room air. Her chest X-ray showed right middle lung opacity measuring 1.9×2.8 cm. She was admitted and started on broad-spectrum antibiotics for suspected pneumonia. Her chest computed tomography (CT) scan showed a 3.0×1.7 cm hypo-dense opacity at the right upper lobe. Overnight, she developed a severe headache and neck stiffness. Her serum cryptococcal antigen and cerebrospinal fluid culture results were positive. The patient was started on intravenous liposomal amphotericin B plus flucytosine. A CT-guided lung biopsy was performed to rule out malignancy. Cultures came back positive for Cryptococcus neoformans. She completed a 2-week course of amphotericin and flucytosine and was switched to oral fluconazole to complete an 8-week course. CONCLUSIONS Prompt diagnosis and effective management of the cryptococcal disease can decrease morbidity and mortality. Diagnosis requires CT-guided lung biopsy, with culture growing mucoid colonies of Cryptococcus neoformans. Antifungal therapy with intravenous liposomal amphotericin B plus flucytosine is the mainstay of treatment. Clinicians should be aware of the various presentations of pulmonary cryptococcosis, especially in immunocompromised patients.

The acceptability of the AMBITION-cm treatment regimen for HIV-associated cryptococcal meningitis: Findings from a qualitative methods study of participants and researchers in Botswana and Uganda.

BACKGROUND: The AMBITION-cm trial for HIV-associated cryptococcal meningitis demonstrated that a single, high-dose of liposomal amphotericin (AmBisome) plus 14-days of oral flucytosine and fluconazole was non-inferior in terms of all-cause mortality to 7-days of amphotericin B deoxycholate and flucytosine followed by 7-days of fluconazole (Control). The AmBisome regimen was associated with fewer adverse events. We explored the acceptability of the AmBisome regimen from the perspective of participants and providers. METHODS: We embedded a qualitative methods study within the AMBITION-cm sites in Botswana and Uganda. We conducted in-depth interviews with trial participants, surrogate decision makers, and researchers and combined these with direct observations. Interviews were transcribed, translated, and analysed thematically. RESULTS: We interviewed 38 trial participants, 20 surrogate decision makers, and 31 researchers. Participant understanding of the trial was limited; however, there was a preference for the AmBisome regimen due to the single intravenous dose and fewer side effects. More time was required to prepare the single AmBisome dose but this was felt to be acceptable given subsequent reductions in workload. The AmBisome regimen was reported to be associated with fewer episodes of rigors and thrombophlebitis and a reduction in the number of intravenous cannulae required. Less intensive monitoring and management was required for participants in the AmBisome arm. CONCLUSIONS: The AmBisome regimen was highly acceptable, being simpler to administer despite the initial time investment required. The regimen was well tolerated and associated with less toxicity and resultant management. Widespread implementation would reduce the clinical workload of healthcare workers caring for patients with HIV-associated cryptococcal meningitis.

Enzyme Prodrug Therapy with Photo-Cross-Linkable Anti-EGFR Affibodies Conjugated to Upconverting Nanoparticles.

In this work, we demonstrate that a photo-cross-linkable conjugate of upconverting nanoparticles and cytosine deaminase can catalyze prodrug conversion specifically at tumor sites in vivo. Non-covalent association of proteins and peptides with cellular surfaces leads to receptor-mediated endocytosis and catabolic degradation. Recently, we showed that covalent attachment of proteins such as affibodies to cell receptors yields extended expression on cell surfaces with preservation of protein function. To adapt this technology for in vivo applications, conjugates were prepared from upconverting nanoparticles and fusion proteins of affibody and cytosine deaminase enzyme (UC-ACD). The affibody allows covalent photo-cross-linking to epidermal growth factor receptors (EGFRs) overexpressed on Caco-2 human colorectal cancer cells under near-infrared (NIR) light. Once bound, the cytosine deaminase portion of the fusion protein converts the prodrug 5-fluorocytosine (5-FC) to the anticancer drug 5-fluorouracil (5-FU). NIR covalent photoconjugation of UC-ACD to Caco-2 cells showed 4-fold higher retention than observed with cells that were not irradiated in vitro. Next, athymic mice expressing Caco-2 tumors showed 5-fold greater UC-ACD accumulation in the tumors than either conjugates without the CD enzyme or UC-ACDs in the absence of NIR excitation. With oral administration of 5-FC prodrug, tumors with photoconjugated UC-ACD yielded 2-fold slower growth than control groups, and median mouse survival increased from 28 days to 35 days. These experiments demonstrate that enzyme-decorated nanoparticles can remain viable after a single covalent photoconjugation in vivo, which can in turn localize prodrug conversion to tumor sites for multiple weeks.

Treatment of Cryptococcal Meningitis: How Have We Got Here and Where are We Going?

Cryptococcal meningitis is a devastating brain infection cause by encapsulated yeasts of the Cryptococcus genus. Exposure, through inhalation, is likely universal by adulthood, but symptomatic infection only occurs in a minority, in most cases, months or years after exposure. Disease has been described in almost all tissues, but it is the organism's tropism for the central nervous system that results in the most devastating illness. While invasive disease can occur in the immunocompetent, the greatest burden by far is in immunocompromised individuals, particularly people living with human immunodeficiency virus (HIV), organ transplant recipients and those on glucocorticoid therapy or other immunosuppressive drugs. Clinical presentation is variable, but diagnosis is usually straightforward, with cerebrospinal fluid microscopy, culture, and antigen testing proving significantly more sensitive than diagnostic tests for other brain infections. Although disease incidence has reduced since the advent of effective HIV therapy, mortality when disease occurs remains extremely high, and has changed little in recent decades. This Therapy in Practice review is an update of a talk first given by JND at the European Congress on Clinical Microbiology and Infectious Diseases in 2019 in the Netherlands. The review contextualizes the most recently published World Health Organization (WHO) guidelines for the treatment of HIV-associated cryptococcal meningitis in terms of the data from large, randomized, controlled trials published between 1997 and 2022. We discuss the rationale for induction and maintenance therapy and the efficacy and undesirable effects of the current therapeutic armamentarium of amphotericin, flucytosine and fluconazole. We address recent research into repurposed drugs such as sertraline and tamoxifen, and potential future treatment options, including the novel antifungals fosmanogepix, efungumab and oteseconazole, and non-pharmaceutical solutions such as neurapheresis cerebrospinal fluid filtration.

Comparison of amphotericin B deoxycholate in combination with either flucytosine or fluconazole, and voriconazole plus flucytosine for the treatment of HIV-associated cryptococcal meningitis: a prospective multicenter study in China.

BACKGROUND: The most appropriate alternative to induction therapy for HIV-associated cryptococcal meningitis (CM) remains unclear when standard treatment is unavailable, inaccessible, intolerable, or ineffective. METHODS: A prospective, multi-centre cohort study was conducted to analyze the data of 156 HIV-infected patients with CM who were treated with amphotericin B deoxycholate (AmB-D) + flucytosine (5FC), voriconazole (VCZ) + 5FC, or AmB-D + Fluconazole (Flu) as induction regimens. Clinical efficacy, cumulative mortality, and adverse effects were compared among the three treatment groups. RESULTS: Fewer deaths occurred by week 4 and week 10 among patients receiving AmB-D + 5FC than among those receiving AmB-D + Flu [4 (5.1%) vs. 8 (16.0%) deaths by week 4; hazard ratio, 1.8; 95% confidence interval [CI], 1.0 to 3.3; p = 0.039; and 8 (10.3%) vs. 14 (28.0%) deaths by week 10; hazard ratio, 1.8; 95% CI, 1.1 to 2.7; p = 0.008, respectively]. AmB-D plus 5FC was found to result in significantly higher rates of cerebrospinal fluid (CSF) culture sterility (57.6% vs. 34% by week 2; 87.9% vs. 70% by week 10; p < 0.05 for both comparisons). However, the differences in CSF culture sterility and mortality between the VCZ + 5FC group and the AmB-D + 5FC group were not statistically significant. VCZ plus 5FC had a significantly advantageous effect on the incidence of new AIDS-defining illness and length of hospital stay, compared with AmB-D plus 5FC. Laboratory adverse events (grade 3 or 4), such as severe anemia, were less frequent with VCZ + 5FC use than with AmB-D combined with 5FC or Flu use. CONCLUSION: Our results suggest that AmB-D combined with 5FC remains the more efficacious induction regimen compared to AmB-D plus Flu, and that VCZ + 5FC might be a potential alternative when the standard regimen is not readily available, accessible, tolerated, or effective. CLINICAL TRIALS: Registration number, ChiCTR1900021195. Registered 1 February 2019, http://www.chictr.org.cn/showproj.aspx?proj=35362 .