In June 2017, The National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, organized a workshop entitled “Pharmacokinetics-Pharmacodynamics (PK/PD) for Development of Therapeutics against Bacterial Pathogens” to discuss details and critical parameters of various PK/PD methods and identify approaches for linking human pharmacokinetic (PK) data and drug efficacy analyses. The workshop participants included individuals from academia, industry, and government.
Aims To examine in vivo the effect of ketoconazole on the pharmacokinetics of rosuvastatin, a 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitor. Methods This was a randomized, double‐blind, two‐way crossover, placebo‐controlled trial. Healthy male volunteers ( n = 14) received ketoconazole 200 mg or placebo twice daily for 7 days, and rosuvastatin 80 mg was coadministered on day 4 of dosing. Plasma concentrations of rosuvastatin, and active and total HMG‐CoA reductase inhibitors were measured up to 96 h postdose. Results Following coadministration with ketoconazole, rosuvastatin geometric least square mean AUC(0, t ) and C max were unchanged compared with placebo (treatment ratios (90% confidence intervals): 1.016 (0.839, 1.230), 0.954 (0.722, 1.260), respectively). Rosuvastatin accounted for essentially all of the circulating active HMG‐CoA reductase inhibitors and most (> 85%) of the total inhibitors. Ketoconazole did not affect the proportion of circulating active or total inhibitors accounted for by circulating rosuvastatin. Conclusions Ketoconazole did not produce any change in rosuvastatin pharmacokinetics in healthy subjects. The data suggest that neither cytochrome P450 3A4 nor P‐gp‐mediated transport contributes to the elimination of rosuvastatin.
Abstract Background DAV132 (colon-targeted adsorbent) has prevented antibiotic-induced effects on microbiota in healthy volunteers. Objectives To assess DAV132 safety and biological efficacy in patients. Patients and methods An open-label, randomized [stratification: fluoroquinolone (FQ) indication] multicentre trial comparing DAV132 (7.5 g, 3 times a day, orally) with No-DAV132 in hospitalized patients requiring 5–21 day treatment with FQs and at risk of Clostridioides difficile infection (CDI). FQ and DAV132 were started simultaneously, DAV132 was administered for 48 h more, and patients were followed up for 51 days. The primary endpoint was the rate of adverse events (AEs) independently adjudicated as related to DAV132 and/or FQ. The planned sample size of 260 patients would provide a 95% CI of ±11.4%, assuming a 33% treatment-related AE rate. Plasma and faecal FQ concentrations, intestinal microbiota diversity, intestinal colonization with C. difficile, MDR bacteria and yeasts, and ex vivo resistance to C. difficile faecal colonization were assessed. Results Two hundred and forty-three patients (median age 71 years; 96% with chronic comorbidity) were included (No-DAV132, n = 120; DAV132, n = 123). DAV132- and/or FQ-related AEs did not differ significantly: 18 (14.8%) versus 13 (10.8%) in DAV132 versus No-DAV132 patients (difference 3.9%; 95% CI: −4.7 to 12.6). Day 4 FQ plasma levels were unaffected. DAV132 was associated with a >98% reduction in faecal FQ levels (Day 4 to end of treatment; P < 0.001), less impaired microbiota diversity (Shannon index; P = 0.003), increased ex vivo resistance to C. difficile colonization (P = 0.0003) and less frequent FQ-induced VRE acquisition (P = 0.01). Conclusions In FQ-treated hospitalized patients, DAV132 was well tolerated, and FQ plasma concentrations unaffected. DAV132 preserved intestinal microbiota diversity and C. difficile colonization resistance.
Nine healthy volunteers aged 18-28 years were recruited into this open, single-centre, two-phase trial. In phase 1, two volunteers received a single dose of 11 C-zolmitriptan 2.5 mg administered as a nasal spray and then underwent positron emission tomography (PET) scanning to determine the most appropriate times for scanning in phase 2. In phase 2, six volunteers received two doses and an additional volunteer one dose of 11 C-zolmitriptan 2.5 mg intranasally. Volunteers underwent PET scanning over sectors covering one of the nasopharynx, lungs or abdomen, for up to 1.5 h postdose. The brain was also scanned and plasma zolmitriptan levels were measured. Almost 100% of the administered dose was detected in the nasopharynx immediately after dosing. This declined thereafter to about 50% at 20 min and to 35% at 80 min after dosing. Radioactivity appeared slowly in the upper abdomen, with 25% of given radioactivity detected at 20 min and persisting until 80 min after dosing. Minimal radioactivity was detected in the lungs. Radioactivity was detectable within brain tissue suggesting central penetration of zolmitriptan. Zolmitriptan in plasma had approached its maximum concentration by 15 min postdose. The data indicate initial absorption across the nasal mucosa contributing to an early systemic availability. 11 C-Zolmitriptan administered intranasally was well tolerated.
Abstract Background Olorofim is a novel antifungal agent active against Aspergillus spp (including azole-resistant strains), rare, resistant moulds (e.g., Lomentospora prolificans) and dimorphic moulds. Serial images of Lomentospora prolificans infection following breast enhancement surgery: progression of healing pre- and post-olorofim therapy. Post-surgical bone/ soft tissue Lomentospora prolificans infection of the chest wall in a healthy woman was uncontrolled with available agents (D -9 visible mould in wound base). At D42/84 overall response on olorofim monotherapy was stable; wound closure with complete resolution of IFI was achieved at D322 (case previously reported, ECCMID 2020 abstract #2585). Methods Patients with limited/no treatment options for proven invasive fungal infection (IFI) or probable pulmonary invasive aspergillosis (IA) using EORTC-MSGERC criteria1 received oral olorofim (150mg BID x1d loading dose then 90mg BID). Outcomes in the first 100 patients are compared with historical controls (HCs) as well as with expected outcomes in patients with baseline highly active, uncontrolled IFI (HAU-IFI). Results All-cause mortality in IA at month 3 (includes data to Day 100, the best-fit time point for IA HC data) was 17/53 (32%, 95 CI 20–46%) for olorofim vs. 40/46 (87%, 74–95%) in HCs given either no therapy or azole monotherapy for azole-resistant IA. Successful EORTC-MSGERC overall response2 (OR, complete or partial based on clinical + radiologic + mycologic improvement) was 47%/42% in IA (Day 42/D84, n = 53), 53%/53% (L. prolificans, n=17), 55%/36% (Scedosporium, n=11), and 50%/50% (other moulds, n=8). Stable response at D42/D84 predicted extended therapy responses, especially in HAU-IFI of brain and bone (Figure). For Coccidioides (n=11) OR was limited to stable due to very slow clearance of fungal serology but clinical response was rapid. Symptoms resolved completely in 18% (2/11) by D84 vs 3% (1/29) by D1523 in comparable HCs with poorly controlled extrapulmonary Coccidioides infection; similar trends were seen for other response measures. Conclusion Olorofim is a novel oral antifungal with activity against a wide range of mould infections which are difficult to treat. Compared with relevant HCs or expected outcomes for HAU-IFI, olorofim has a positive benefit-risk profile in a well-defined population of patients with limited/no treatment options. As noted previously3, considering stable in overall success if often appropriate when assessing responses in non-IA mould IFI. References: 1. Donnelly CID 2020; 71:1367–76 2. Segal CID 2008; 47:674–83 3. Perfect Mycoses 2018: 61:420 Disclosures Johan A. Maertens, MD PhD, F2G Ltd: Advisor/Consultant|Gilead Sciences Ltd: Advisor/Consultant|Mundipharma: Advisor/Consultant|Pfizer Inc: Advisor/Consultant Paul E. Verweij, PhD, Gilead: Grant/Research Support Emma L. Harvey, MBBS, F2G Ltd: Stocks/Bonds Aaron Dane, MSc, Amplyx: Advisor/Consultant|AN2 therapeutics: Advisor/Consultant|Artizan: Advisor/Consultant|Cidara: Advisor/Consultant|ContraFect: Advisor/Consultant|Correvio: Advisor/Consultant|Davolterra: Advisor/Consultant|Destiny Pharma: Advisor/Consultant|Entasis: Advisor/Consultant|F2G Limited: Advisor/Consultant|GSK: Advisor/Consultant|Humanigen: Advisor/Consultant|Kymab: Advisor/Consultant|Modis: Advisor/Consultant|Orca: Advisor/Consultant|Pfizer: Advisor/Consultant|Phico: Advisor/Consultant|Pled Pharma: Advisor/Consultant|Rare Thyroid: Advisor/Consultant|Roche: Advisor/Consultant|Scynexis: Advisor/Consultant|Sinovent: Advisor/Consultant|Spero Therapeutics: Advisor/Consultant|Transcrip: Advisor/Consultant|Venatorx: Advisor/Consultant Daniela Zinzi, Infectious Diseases Specialist, F2G: F2G employee|F2G: Stocks/Bonds John H. Rex, MD, Advent Life Sciences: Operating Partner|Advent Life Sciences: Ownership Interest|AMR Action Fund: Advisor/Consultant|AstraZeneca: Stocks/Bonds|Basilea Pharmaceutica: Advisor/Consultant|Bugworks Research, Inc.: Advisor/Consultant|F2G, Limited: Employee|F2G, Limited: Stocks/Bonds|Forge Therapeutics: Advisor/Consultant|GlaxoSmithKline: Advisor/Consultant|Pfizer Pharmaceuticals: Honoraria|Sumitovant: Advisor/Consultant Sharon C. Chen, PhD MBBS, F2G PTy Ltd: Grant/Research Support|MSD Australia: Grant/Research Support.
At present, there are situations in antibiotic drug development where the low number of enrollable patients with key problem pathogens makes it impossible to conduct fully powered non-inferiority trials in the traditional way. Recent regulatory changes have begun to address this situation. In parallel, statistical issues regarding the application of alternative techniques, balancing the unmet need with the level of certainty in the approval process, and the use of additional sources of data are critical areas to increase development feasibility. Although such approaches increase uncertainty compared with a traditional development program, this will be necessary to allow new agents to be made available. Identification of these risks and explicit discussion around requirements in these areas should help clarify the situation, and hence, the feasibility of developing drugs to treat the most concerning pathogens before the unmet need becomes even more acute than at present.