Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study. APPROACH AND RESULTS: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings. CONCLUSIONS: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.

Predictors of 6-year event-free survival in Alagille syndrome patients treated with maralixibat, an ileal bile acid transporter inhibitor.

BACKGROUND AND AIMS: Refractory pruritus and other complications of cholestasis are indications for liver transplantation (LT) in patients with Alagille syndrome (ALGS). We evaluated predictors of event-free survival and transplant-free survival in patients with ALGS treated with maralixibat (MRX), an ileal bile acid transporter inhibitor. APPROACH AND RESULTS: We assessed patients with ALGS from 3 clinical trials of MRX with up to 6 years of follow-up. Event-free survival was defined as the absence of LT, surgical biliary diversion, hepatic decompensation, or death; transplant-free survival was the absence of LT or death. Forty-three potential predictors were evaluated, including age, pruritus (ItchRO[Obs] 0-4 scale), biochemistries, platelets, and serum bile acids. Harrell's concordance statistic assessed goodness-of-fit, and then, Cox proportional hazard models confirmed the statistical significance of the predictors identified. A further analysis was performed to identify cutoffs using a grid search. Seventy-six individuals met the criteria of receiving MRX for ≥48 weeks with laboratory values available at week 48 (W48). The median duration of MRX was 4.7 years (IQR: 1.6-5.8); 16 had events (10 LT, 3 decompensation, 2 death, and 1 surgical biliary diversion). The 6-year event-free survival improved with a clinically meaningful >1-point ItchRO(Obs) reduction from baseline to W48 (88% vs. 57%; p = 0.005), W48 bilirubin < 6.5 mg/dL (90% vs. 43%; p < 0.0001), and W48 serum bile acid < 200 µmol/L (85% vs. 49%; p = 0.001). These parameters were also predictive of 6-year transplant-free survival. CONCLUSIONS: Improvement in pruritus by 48 weeks, and lower W48 bilirubin and serum bile acid levels were associated with fewer events. These data may help identify potential markers of disease progression for ALGS patients treated with MRX.

Maralixibat Treatment Response in Alagille Syndrome is Associated with Improved Health-Related Quality of Life.

OBJECTIVE: The objective of this study was to assess the impact of treatment response to the ileal bile acid transporter inhibitor maralixibat on health-related quality of life (HRQoL) in children with Alagille syndrome. STUDY DESIGN: This analysis used data from the ICONIC trial, a phase 2 study with a 4-week double-blind, placebo-controlled, randomized drug withdrawal period in children with Alagille syndrome with moderate-to-severe pruritus. Clinically meaningful treatment response to maralixibat was defined a priori as a ≥1-point reduction in the Itch-Reported Outcome (Observer) score, from baseline to week 48. HRQoL was assessed using the Pediatric Quality of Life Inventory Generic Core, Family Impact, and Multidimensional Fatigue scale scores, which were collected via the caregiver. The minimal clinically important difference for HRQoL ranged from 4 to 5 points, depending on the scale. RESULTS: Twenty of the 27 patients (74%) included in this analysis achieved an Itch-Reported Outcome (Observer) treatment response at week 48. The mean (SD) change in Multidimensional Fatigue score was +25.8 (23.0) for responders vs -3.1 (19.8) for nonresponders (P = .03). Smaller and non-statistically significant mean changes were observed for the Pediatric Quality of Life Inventory Generic Core and Family Impact scores. Controlling for baseline Family Impact score, responders' Family Impact scores increased an average of 16.9 points over 48 weeks compared with non-responders (P = .05). Smaller and non-statistically significant point estimates were observed for the Pediatric Quality of Life Inventory Generic Core and Multidimensional Fatigue scores. CONCLUSION: The significant improvements in pruritus seen with maralixibat at week 48 of the ICONIC study are clinically meaningful and are associated with improved HRQoL. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02160782.

Investigational non-antibiotic therapeutics for infections in hematopoietic cell transplant recipients and patients with hematologic malignancies receiving cellular therapies.

In the age of progressive antimicrobial resistance and increased difficulty combating infections in immunocompromised hosts, there has been renewed interest in the use of nontraditional therapeutics for infections. Herein, we review the use of investigational non-pharmaceutical anti-infective agents targeting fungal, bacterial, and viral infections in patients with hematologic malignancies, focusing on those receiving hematopoietic cell transplantation or cellular therapies. We discuss immune checkpoint inhibitors, granulocyte transfusions, bone marrow colony-stimulating factors, bacteriophages, fecal microbiota transplantation, and virus specific T-cell therapy. Although there is promising early experience with many of these treatments, further studies will be required to define their optimal role in the therapeutic armamentarium against infections in immunocompromised hosts.

Efficacy and safety of maralixibat treatment in patients with Alagille syndrome and cholestatic pruritus (ICONIC): a randomised phase 2 study.

BACKGROUND: Alagille syndrome is a rare genetic disease that often presents with severe cholestasis and pruritus. There are no approved drugs for management. Maralixibat, an apical, sodium-dependent, bile acid transport inhibitor, prevents enterohepatic bile acid recirculation. We evaluated the safety and efficacy of maralixibat for children with cholestasis in Alagille syndrome. METHODS: ICONIC was a placebo-controlled, randomised withdrawal period (RWD), phase 2b study with open-label extension in children (aged 1-18 years) with Alagille syndrome (NCT02160782). Eligible participants had more than three times the normal serum bile acid (sBA) levels and intractable pruritus. After 18 weeks of maralixibat 380 µg/kg once per day, participants were randomly assigned (1:1) to continue maralixibat or receive placebo for 4 weeks. Subsequently, all participants received open-label maralixibat until week 48. During the long-term extension (204 weeks reported), doses were increased up to 380 µg/kg twice per day. The primary endpoint was the mean sBA change during the RWD in participants with at least 50% sBA reduction by week 18. Cholestastic pruritus was assessed using observer-rated, patient-rated, and clinician-rated 0-4 scales. The safety population was defined as all participants who had received at least one dose of maralixibat. This trial was registered with ClinicalTrials.gov, NCT02160782, and is closed to recruitment. FINDINGS: Between Oct 28, 2014, and Aug 14, 2015, 31 participants (mean age 5·4 years [SD 4·25]) were enrolled and 28 analysed at week 48. Of the 29 participants who entered the randomised drug withdrawal period, ten (34%) were female and 19 (66%) were male. In the RWD, participants switched to placebo had significant increases in sBA (94 µmol/L, 95% CI 23 to 164) and pruritus (1·7 points, 95% CI 1·2 to 2·2), whereas participants who continued maralixibat maintained treatment effect. This study met the primary endpoint (least square mean difference -117 µmol/L, 95% CI -232 to -2). From baseline to week 48, sBA (-96 µmol/L, -162 to -31) and pruritus (-1·6 pts, -2·1 to -1·1) improved. In participants who continued to week 204 (n=15) all improvements were maintained. Maralixibat was generally safe and well tolerated throughout. The most frequent adverse events were gastrointestinal related. Most adverse events were self-limiting in nature and mild-to-moderate in severity. INTERPRETATION: In children with Alagille syndrome, maralixibat is, to our knowledge, the first agent to show durable and clinically meaningful improvements in cholestasis. Maralixibat might represent a new treatment paradigm for chronic cholestasis in Alagille syndrome. FUNDING: Mirum Pharmaceuticals.

Infections after anti-CD19 chimeric antigen receptor T-cell therapy for hematologic malignancies: timeline, prevention, and uncertainties.

PURPOSE OF REVIEW: Data on the infectious complications of anti-CD19 chimeric antigen receptor-modified T-cell (CAR-T-cell) therapies are scant. The approaches to preventing and managing infections among CAR-T-cell recipients are extrapolated from those of patients with other hematological malignancies. Understanding the incidence and risk factors of infections in these patients will improve clinical outcomes. RECENT FINDINGS: Infections occur in 23-42% of CAR-T-cell recipients and are most frequent in the first month after infusion, declining sharply thereafter. Risk factors include preinfusion (e.g., prior hematopoietic cell transplant, underlying malignancy) and postinfusion variables (e.g., cytokine release syndrome [CRS], neutropenia). Neutropenic fever after CAR-T-cell therapy is nearly universal but is confounded by CRS. The timeline of infections can be divided into preinfusion (because of the preparative regimen); 0-30 days after infusion, when bacterial infections predominate; and 30 days onwards, when respiratory viral infections predominate. Fungal and herpesviridae infections are uncommon. SUMMARY: Recent studies have shed light on the epidemiology of infections after CAR-T-cell therapy. Future efforts should focus on identifying modifiable risk factors for infection, defining neutropenic fever in the setting of CRS, determining the benefit of antimold prophylaxis, and identifying the optimal approach to viral monitoring, vaccination, and immunoglobulin replacement.

Coformulated bictegravir, emtricitabine, and tenofovir alafenamide versus dolutegravir with emtricitabine and tenofovir alafenamide, for initial treatment of HIV-1 infection (GS-US-380-1490): a randomised, double-blind, multicentre, phase 3, non-inferiority trial.

BACKGROUND: Integrase strand transfer inhibitors (INSTIs) coadministered with two nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) are recommended as first-line treatment for HIV, and coformulated fixed-dose combinations are preferred to facilitate adherence. We report 48-week results from a study comparing initial HIV-1 treatment with bictegravir-a novel INSTI with a high in-vitro barrier to resistance and low potential as a perpetrator or victim of clinically relevant drug interactions-coformulated with the NRTI combination emtricitabine and tenofovir alafenamide as a fixed-dose combination to dolutegravir administered with coformulated emtricitabine and tenofovir alafenamide. METHODS: In this randomised, double-blind, multicentre, placebo-controlled, non-inferiority trial, HIV-infected adults were screened and enrolled at 126 outpatient centres in 10 countries in Australia, Europe, Latin America, and North America. Participants were previously untreated adults (HIV-1 RNA ≥500 copies per mL) with estimated glomerular filtration rate of at least 30 mL/min. Chronic hepatitis B virus or hepatitis C co-infection was allowed. We randomly assigned participants (1:1) to receive oral fixed-dose combination bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg or dolutegravir 50 mg with coformulated emtricitabine 200 mg and tenofovir alafenamide 25 mg, with matching placebo, once a day for 144 weeks. Investigators, participants, study staff, and those assessing outcomes were masked to treatment group. All participants who received at least one dose of study drug were included in primary efficacy and safety analyses. The primary endpoint was the proportion of participants with plasma HIV-1 RNA of less than 50 copies per mL at week 48 (US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of -12%. This study is registered with ClinicalTrials.gov, number NCT02607956. FINDINGS: Between Nov 11, 2015, and July 15, 2016, 742 participants were screened for eligibility, of whom 657 were randomly assigned to treatment (327 with bictegravir, emtricitabine, and tenofovir alafenamide fixed-dose combination [bictegravir group] and 330 with dolutegravir plus emtricitabine and tenofovir alafenamide [dolutegravir group]). 320 participants who received the bictegravir regimen and 325 participants who received the dolutegravir regimen were included in the primary efficacy analyses. At week 48, HIV-1 RNA <50 copies per mL was achieved in 286 (89%) of 320 participants in the bictegravir group and 302 (93%) of 325 in the dolutegravir group (difference -3·5%, 95·002% CI -7·9 to 1·0, p=0·12), showing non-inferiority of the bictegravir regimen to the dolutegravir regimen. No treatment-emergent resistance to any study drug was observed. Incidence and severity of adverse events were similar between groups, and few participants discontinued treatment due to adverse events (5 [2%] of 320 in the bictegravir group and 1 [<1%] 325 in the dolutegravir group). Study drug-related adverse events were less common in the bictegravir group than in the dolutegravir group (57 [18%] of 320 vs 83 [26%] of 325, p=0·022). INTERPRETATION: At 48 weeks, virological suppression with the bictegravir regimen was achieved and was non-inferior to the dolutegravir regimen in previously untreated adults. There was no emergent resistance to either regimen. The fixed-dose combination of bictegravir, emtricitabine, and tenofovir alafenamide was safe and well tolerated compared with the dolutegravir regimen. FUNDING: Gilead Sciences Inc.

Gaps in Preexposure Prophylaxis Uptake for HIV Prevention in the Veterans Health Administration.

OBJECTIVES: To report demographics, regional variations, and indications for preexposure prophylaxis (PrEP) use for HIV prevention in the Veterans Health Administration (VHA). METHODS: We identified persons initiating tenofovir/emtricitabine for the PrEP indication in the United States between July 2012 and April 2016 in a VHA national database. We stratified PrEP use by provider type and VHA region. We calculated PrEP initiation rate for each region with VHA population data. RESULTS: Of the 825 persons who initiated PrEP during the observation period, 67% were White and 76% were men who have sex with men. People who inject drugs and transgender persons represented less than 1% each of the cohort. The majority of PrEP initiations were clustered in 3 states, leading with California (28%) followed by Florida (9%) and Texas (8%). The Southeast had one of the lowest PrEP rates at 10 PrEP initiations per 100 000 persons in care. Infectious disease specialists issued more than two thirds of index PrEP prescriptions. CONCLUSIONS: Uptake of PrEP in the VHA is uneven along geographic and risk categories. Understanding the reasons behind these gaps will be key in expanding the use of this important prevention tool.

Randomized comparison of liposomal amphotericin B versus placebo to prevent invasive mycoses in acute lymphoblastic leukaemia.

Objectives: To prevent invasive fungal disease (IFD) in adult patients undergoing remission-induction chemotherapy for newly diagnosed acute lymphoblastic leukaemia (ALL). Patients and methods: In a double-blind multicentre Phase 3 study, patients received prophylactic liposomal amphotericin B (L-AMB) at 5 mg/kg intravenously or placebo twice weekly in a 2:1 random allocation during remission-induction treatment. The primary endpoint was the development of proven or probable IFD. Secondary endpoints included those focused on the safety and tolerability of prophylactic L-AMB. Results: Three hundred and fifty-five patients from 86 centres in Europe and South America received at least one dose of L-AMB ( n = 237) or placebo ( n = 118). Rates of proven and probable IFD assessed independently were 7.9% (18/228) in the L-AMB group and 11.7% (13/111) in the placebo group ( P = 0.24). Rates of possible IFD were 4.8% (11/228) in the L-AMB and 5.4% (6/111) in the placebo group ( P = 0.82). The remission-induction phase was a median of 22 days for both groups. Overall mortality was similar between the groups: 7.2% (17/237) for L-AMB and 6.8% (8/118) for placebo ( P = 1.00). Hypokalaemia and creatinine increase were significantly more frequent with L-AMB. Conclusions: The IFD rate among adult patients undergoing remission-induction chemotherapy for newly diagnosed ALL was 11.7% in the placebo group, and was not significantly different in patients receiving L-AMB, suggesting that the L-AMB regimen studied is not effective as prophylaxis against IFD. The IFD rate appears higher than previously reported, warranting further investigation. Tolerability of L-AMB was what might be expected. Further studies are needed to determine the optimal antifungal strategy during remission-induction chemotherapy of ALL.

Concordance of HIV-1 RNA Values by Amplicor and TaqMan 2.0 in Patients With Confirmed Suppression in Clinical Trials.

BACKGROUND: The COBAS AMPLICOR HIV-1 MONITOR Test, version 1.5 (Amplicor) has been replaced with the COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, version 2.0 (TaqMan 2.0), a real-time polymerase chain reaction human immunodeficiency virus type 1 (HIV-1) assay with higher sensitivity and broader dynamic range. HIV-1 RNA values at the 50 copies/mL cutoff drive major patient management decisions and clinical study outcomes. METHODS: A total of 2217 samples were collected from 1922 HIV-1-infected subjects taking antiretroviral therapy for at least 48 weeks and had at least 2 consecutive samples with HIV-1 RNA <50 copies/mL by Amplicor from 7 recent clinical trials. HIV-1 RNA results were obtained from the Amplicor and TaqMan 2.0 assays in parallel by a reference laboratory. RESULTS: The overall concordance between assay results was 96% at the cutoff of 50 copies/mL. However, statistically significant discordance at the 50 copies/mL cutoff was found between the assays for 3.9% of samples (n = 87). By TaqMan 2.0, virologic failure defined as HIV-1 RNA ≥ 50 copies/mL was reported for 2.8% more samples than Amplicor. Of these 87 samples, 68 samples fell within the predicted range of assay variability. Retesting of HIV-1 RNA by TaqMan 2.0 confirmed the discordance in only 28 of the 87 samples. CONCLUSIONS: The TaqMan 2.0 assay reports fewer subjects below the clinical endpoint of HIV-1 RNA <50 copies/mL in HIV clinical trials than the Amplicor assay. This difference must be considered when assessing disease progression, designing clinical trials, and comparisons with historical trials that used the Amplicor assay.

Patient-reported outcomes in the single-tablet regimen (STaR) trial of rilpivirine/emtricitabine/tenofovir disoproxil fumarate versus efavirenz/emtricitabine/tenofovir disoproxil fumarate in antiretroviral treatment-naive adults infected with HIV-1 through 48 weeks of treatment.

This 96-week, randomized, open-label study was designed to assess the efficacy and safety of two single-tablet regimens in treatment naïve HIV-1-infected adults: rilpivirine (RPV) + emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) and efavirenz (EFV) + FTC/TDF. Assessments included patient-reported Medication Adherence Self-Report Inventory, SF-12v2 Quality of Life assessment, HIV Treatment Satisfaction Questionnaire, and HIV Symptom Index Questionnaire through Week 48. Additional evaluations included study drug discontinuations due to treatment-emergent adverse events (TEAEs). A total of 786 participants (n=394 RPV/FTC/TDF, n=392 EFV/FTC/TDF) were included. Fewer RPV/FTC/TDF-treated than EFV/FTC/TDF-treated participants discontinued study drug due to TEAEs (2.5% vs. 8.7%), with 41% (14/34) TEAE-related discontinuations in the EFV/FTC/TDF group occurring within the first four weeks of treatment. Treatment adherence and satisfaction remained high through Week 48 and quality of life improved from baseline in both groups. There were no significant between-group differences in virologic success (HIV-1 RNA <50 copies/mL) regardless of adherence (<95% or ≥95%). Significant between-group differences favouring RPV/FTC/TDF were observed for the HIV SIQ symptoms of difficulty falling or staying asleep (p = .022) and diarrhea or loose bowel movements (p = .002). In conclusion, 48-week treatment with RPV/FTC/TDF or EFV/FTC/TDF was associated with high adherence, high treatment satisfaction, and improved quality of life. TEAE-related discontinuations and patient-reported symptoms indicate that RPV/FTC/TDF may be somewhat better tolerated than EFV/FTC/TDF.

Maralixibat in progressive familial intrahepatic cholestasis (MARCH-PFIC): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Progressive familial intrahepatic cholestasis (PFIC) is a group of autosomal recessive disorders, the most prevalent being BSEP deficiency, resulting in disrupted bile formation, cholestasis, and pruritus. Building on a previous phase 2 study, we aimed to evaluate the efficacy and safety of maralixibat-an ileal bile acid transporter inhibitor-in participants with all types of PFIC. METHODS: MARCH-PFIC was a multicentre, randomised, double-blind, placebo-controlled, phase 3 study conducted in 29 community and hospital centres across 16 countries in Europe, the Americas, and Asia. We recruited participants aged 1-17 years with PFIC with persistent pruritus (>6 months; average of ≥1·5 on morning Itch-Reported Outcome [Observer; ItchRO(Obs)] during the last 4 weeks of screening) and biochemical abnormalities or pathological evidence of progressive liver disease, or both. We defined three analysis cohorts. The BSEP (or primary) cohort included only those with biallelic, non-truncated BSEP deficiency without low or fluctuating serum bile acids or previous biliary surgery. The all-PFIC cohort combined the BSEP cohort with participants with biallelic FIC1, MDR3, TJP2, or MYO5B deficiencies without previous surgery but regardless of bile acids. The full cohort had no exclusions. Participants were randomly assigned (1:1) to receive oral maralixibat (starting dose 142·5 µg/kg, then escalated to 570 µg/kg) or placebo twice daily for 26 weeks. The primary endpoint was the mean change in average morning ItchRO(Obs) severity score between baseline and weeks 15-26 in the BSEP cohort. The key secondary efficacy endpoint was the mean change in total serum bile acids between baseline and the average of weeks 18, 22, and 26 in the BSEP cohort. Efficacy analyses were done in the intention-to-treat population (all those randomly assigned) and safety analyses were done in all participants who received at least one dose of study drug. This completed trial is registered with ClinicalTrials.gov, NCT03905330, and EudraCT, 2019-001211-22. FINDINGS: Between July 9, 2019, and March 4, 2022, 125 patients were screened, of whom 93 were randomly assigned to maralixibat (n=47; 14 in the BSEP cohort and 33 in the all-PFIC cohort) or placebo (n=46; 17 in the BSEP cohort and 31 in the all-PFIC cohort), received at least one dose of study drug, and were included in the intention-to-treat and safety populations. The median age was 3·0 years (IQR 2·0-7·0) and 51 (55%) of 93 participants were female and 42 (45%) were male. In the BSEP cohort, least-squares mean change from baseline in morning ItchRO(Obs) was -1·7 (95% CI -2·3 to -1·2) with maralixibat versus -0·6 (-1·1 to -0·1) with placebo, with a significant between-group difference of -1·1 (95% CI -1·8 to -0·3; p=0·0063). Least-squares mean change from baseline in total serum bile acids was -176 µmol/L (95% CI -257 to -94) for maralixibat versus 11 µmol/L (-58 to 80) for placebo, also representing a significant difference of -187 µmol/L (95% CI -293 to -80; p=0·0013). The most common adverse event was diarrhoea (27 [57%] of 47 patients on maralixibat vs nine [20%] of 46 patients on placebo; all mild or moderate and mostly transient). There were five (11%) participants with serious treatment-emergent adverse events in the maralixibat group versus three (7%) in the placebo group. No treatment-related deaths occurred. INTERPRETATION: Maralixibat improved pruritus and predictors of native liver survival in PFIC (eg, serum bile acids). Maralixibat represents a non-surgical, pharmacological option to interrupt the enterohepatic circulation and improve the standard of care in patients with PFIC. FUNDING: Mirum Pharmaceuticals.

Maralixibat for the treatment of PFIC: Long-term, IBAT inhibition in an open-label, Phase 2 study.

Children with progressive familial intrahepatic cholestasis, including bile salt export pump (BSEP) and familial intrahepatic cholestasis-associated protein 1 (FIC1) deficiencies, suffer debilitating cholestatic pruritus that adversely affects growth and quality of life (QoL). Reliance on surgical interventions, including liver transplantation, highlights the unmet therapeutic need. INDIGO was an open-label, Phase 2, international, long-term study to assess the efficacy and safety of maralixibat in children with FIC1 or BSEP deficiencies. Thirty-three patients, ranging from 12 months to 18 years of age, were enrolled. Eight had FIC1 deficiency and 25 had BSEP deficiency. Of the latter, 6 had biallelic, protein truncating mutations (t)-BSEP, and 19 had ≥ 1 nontruncating mutation (nt)-BSEP. Patients received maralixibat 266 µg/kg orally, once daily, from baseline to Week 72, with twice-daily dosing permitted from Week 72. Long-term efficacy was determined at Week 240. Serum bile acid (sBA) response (reduction in sBAs of > 75% from baseline or concentrations <102.0 µmol/L) was achieved in 7 patients with nt-BSEP, 6 during once-daily dosing, and 1 after switching to twice-daily dosing. sBA responders also demonstrated marked reductions in sBAs and pruritus, and increases in height, weight, and QoL. All sBA responders remained liver transplant-free after > 5 years. No patients with FIC1 deficiency or t-BSEP deficiency met the sBA responder criteria during the study. Maralixibat was generally well-tolerated throughout the study. Conclusion: Response to maralixibat was dependent on progressive familial intrahepatic cholestasis subtype, and 6 of 19 patients with nt-BSEP experienced rapid and sustained reductions in sBA levels. The 7 responders survived with native liver and experienced clinically significant reductions in pruritus and meaningful improvements in growth and QoL. Maralixibat may represent a well-tolerated alternative to surgical intervention.

Quantitative analysis of spatial-temporal correlations during germination of spores of Bacillus Species.

Bacteria of Bacillus species sporulate upon starvation, and the resultant dormant spores germinate when the environment appears likely to allow the resumption of vegetative growth. Normally, the rates of germination of individual spores in populations are very heterogeneous, and the current work has investigated whether spore-to-spore communication enhances the synchronicity of germination. In order to do this work, time-lapse optical images of thousands of individual spores were captured during germination, and an image analysis algorithm was developed to do the following: (i) measure the positions and germination rates of many thousands of individual spores and (ii) compute pairwise correlations of their germination. This analysis showed that an individual spore's germination rate was dependent on its distance from other spores, especially at short distances. Thus, spores that were within a few micrometers exhibited an increased synchronicity in germination, suggesting that there is a mechanism for short-range communication between such spores during germination. However, two molecules known to be germinants that are released during germination, l-alanine and the 1:1 chelate of Ca²âº and dipicolinic acid, did not mediate spore-to-spore communication during germination.

Invasive Fungal Infections after Anti-CD19 Chimeric Antigen Receptor-Modified T-Cell Therapy: State of the Evidence and Future Directions.

Studies describing invasive fungal infections (IFIs) after chimeric antigen receptor-modified T-cell (CAR-T-cell) therapy are limited. Although post-CAR-T-cell IFIs appear to be uncommon, they are associated with significant morbidity and mortality. Specific risk factors for IFIs in CAR-T-cell recipients have not been fully characterized and are often extrapolated from variables contributing to IFIs in patients with other hematologic malignancies or those undergoing hematopoietic cell transplant. Optimal prophylaxis strategies, including the use of yeast versus mold-active azoles, also remain ill-defined. Further research should investigate key risk factors for IFIs and establish an evidence-based approach to antifungal prophylaxis in these patients in order to improve clinical outcomes.

Model-Informed Drug Development of the Masked Anti-PD-L1 Antibody CX-072.

CX-072 is an anti-PD-L1 (programmed death ligand 1) Probody therapeutic (Pb-Tx) designed to be preferentially activated by proteases in the tumor microenvironment and not in healthy tissue. Here, we report the model-informed drug development of CX-072. A quantitative systems pharmacology (QSP) model that captured known mechanisms of Pb-Tx activation, biodistribution, elimination, and target engagement was used to inform clinical translation. The QSP model predicted that a trough level of masked CX-072 (intact CX-072) of 13-99 nM would correspond to a targeted, 95% receptor occupancy in the tumor. The QSP model predictions appeared consistent with preliminary human single-dose pharmacokinetic (PK) data following CX-072 0.03-30.0 mg/kg as monotherapy: CX-072 circulated predominantly as intact CX-072 with minimal evidence of target-mediated drug disposition. A preliminary population PK (POPPK) analysis based upon 130 subjects receiving 0.03-30.0 mg/kg as monotherapy included a provision for a putative time-dependent and dose-dependent antidrug antibody (ADA) effect on clearance (CL) with a mixture model. Preliminary POPPK estimates for intact CX-072 time-invariant CL and volume of distribution were 0.306 L/day and 4.84 L, respectively. Exposure-response analyses did not identify statistically significant relationships with best change from baseline sum of measurements and either adverse events of grade ≥ 3 or of special interest. Simulations suggested that > 95% of patients receiving CX-072 10 mg/kg every two weeks would exceed the targeted trough level regardless of ADA, and that dose adjustment by body weight was not necessary, supporting a fixed 800 mg dose for evaluation in phase II.

Factors affecting variability in time between addition of nutrient germinants and rapid dipicolinic acid release during germination of spores of Bacillus species.

The simultaneous nutrient germination of hundreds of individual wild-type spores of three Bacillus species and a number of Bacillus subtilis strains has been measured by two new methods, and rates of release of the great majority of the large pool of dipicolinic acid (DPA) from individual spores of B. subtilis strains has been measured by Raman spectroscopy with laser tweezers. The results from these analyses and published data have allowed a number of significant conclusions about the germination of spores of Bacillus species as follows. (i) The time needed for release of the great majority of a Bacillus spore's DPA once rapid DPA release had begun (DeltaT(release)) during nutrient germination was independent of the concentration of nutrient germinant used, the level of the germinant receptors (GRs) that recognize nutrient germinants used and heat activation prior to germination. Values for DeltaT(release) were generally 0.5 to 3 min at 25 to 37 degrees C for individual wild-type spores. (ii) Despite the conclusion above, germination of individual spores in populations was very heterogeneous, with some spores in wild-type populations completing germination > or = 15-fold slower than others. (iii) The major factor in the heterogeneity in germination of individual spores in populations was the highly variable lag time, T(lag), between mixing spores with nutrient germinants and the beginning of DeltaT(release). (iv) A number of factors decrease spores' T(lag) values including heat activation, increased levels of GRs/spore, and higher levels of nutrient germinants. These latter factors appear to affect the level of activated GRs/spore during nutrient germination. (v) The conclusions above lead to the simple prediction that a major factor causing heterogeneity in Bacillus spore germination is the number of functional GRs in individual spores, a number that presumably varies significantly between spores in populations.

Brief Report: Incidence of HIV in a Nationwide Cohort Receiving Pre-exposure Prophylaxis for HIV Prevention.

BACKGROUND: Cases of HIV, while infrequent, have been reported during tenofovir disoproxil fumarate/emtricitabine use as pre-exposure prophylaxis (PrEP). We describe the incidence of HIV and patterns of PrEP use within the Veterans Health Administration (VHA). METHODS: We conducted a retrospective cohort study among persons initiating PrEP in the VHA between July 2012 and April 2016 using national VHA data. We defined time on PrEP and time at risk of HIV exposure as the total time from the first PrEP fill to exhaustion of supply of the final PrEP prescription. We identified incident cases of HIV infection after PrEP initiation based on laboratory data. Medication adherence measures and days without pills were calculated using pharmacy fill data. We used a chart review to determine patient-reported PrEP use around the time of diagnosis. RESULTS: We identified 825 unique patients initiating PrEP; they were 97% men and 67% white, with a mean age of 41 years. Six HIV infections were observed during the study period, yielding an HIV incidence of 0.8 (Poisson exact 95% confidence interval: 0.3 to 1.8) cases per 100 person-years. Two cases occurred during active PrEP use by self-report and perfect adherence based on fill data. Both were infected with viruses containing the M184V mutation. Four additional cases were diagnosed after self-reported discontinuation. CONCLUSIONS: HIV infection was rare in a nationwide cohort of PrEP users. Although most of the infections occurred during inconsistent PrEP use, infections during periods of high measured adherence were also observed. These findings highlight the importance of PrEP persistence during periods of risk.

Randomized study evaluating the efficacy and safety of switching from an an abacavir/lamivudine-based regimen to an elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide single-tablet regimen.

OBJECTIVE: To evaluate the efficacy and safety of switching from an abacavir/lamivudine (ABC/3TC)-based regimen to an elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) single-tablet regimen in virologically suppressed, HIV-1-infected adults. DESIGN: Randomized, open-label, noninferiority study. METHODS: Participants with HIV-1 RNA levels less than 50 copies/ml receiving ABC/3TC plus a third agent for at least 6 months were randomized 2 : 1 to switch immediately to E/C/F/TAF (immediate-switch group) for 48 weeks or to continue receiving ABC/3TC plus a third agent for 24 weeks followed by E/C/F/TAF for 24 weeks (delayed-switch group). The primary endpoint was HIV-1 RNA less than 50 copies/ml at Week 24 by Food and Drug Administration Snapshot algorithm (-12% noninferiority margin). RESULTS: Baseline characteristics of 274 participants (183 in immediate-switch group and 91 in delayed-switch group) were similar. Virologic response was maintained at Week 24 by 93.4 and 97.8% of participants in the immediate-switch and delayed-switch groups, respectively, with a treatment difference of -4.4% (95% confidence interval: -9.4 to 1.9%), confirming noninferiority. Adverse events of any grade were similar between groups through Week 24 (66% E/C/F/TAF, 64% ABC/3TC); adverse event-related drug discontinuations occurred in 4% of participants switching to E/C/F/TAF (no discontinuations because of renal events) and no participants continuing ABC/3TC. Renal biomarkers of urine albumin:creatinine and beta-2-microglobulin:creatinine ratios significantly improved on E/C/F/TAF. Self-reported treatment satisfaction was significantly higher with E/C/F/TAF. CONCLUSION: Switching to E/C/F/TAF was noninferior to continuing ABC/3TC plus a third agent for maintenance of HIV RNA suppression at Week 24. This study supports E/C/F/TAF as an efficacious and well tolerated option for participants switching from ABC/3TC-based regimens.