Isopp 2023

The proceedings contain 109 papers. The topics discussed include: dose intensity of palbociclib and initial body weight dosage: implications on progression free survival in 220 patients with ER+/HER2-negative metastatic breast cancer;characteristics of Nirmatrelvir/Ritonavir (Paxlovid) recipients and clinical interventions by oncology pharmacists at a tertiary outpatient cancer center;safe handling of non-carcinogenic drugs in the Ghent University Hospital: development, implementation and communication of hospital-specific guidelines;case series: use of olaparib in uncommon locations in patients with impaired homologous recombination;real-world data evaluation of medicines used in special situations in oncohematology: a retrospective study from a comprehensive cancer institution;Dostarlimab in the treatment of recurrent endometrial cancer: real life experience;medication-related osteonecrosis of the jaws and CDK4/6 inhibitors in breast cancer;and efficacy and safety outcomes of generic imatinib in adults with chronic myeloid leukemia (CML) following the switch from branded imatinib.

Bioequivalence study of generic nirmatrelvir in healthy volunteers

Nirmatrelvir is an antiviral drug that, in combination with ritonavir, is an effective agent for the etiotropic therapy of patients with mild to moderate COVID-19. The aim of the study was to evaluate bioequivalence of the generic drug nirmatrelvir Arpaxel in combination with ritonavir and the original drug Paxlovid, which is a combination of nirmatrelvir/ritonavir, in a single dose administration to healthy volunteers.Materials and methods. This research was an open-label, randomized, two-period crossover bioequivalence study. It included 2 periods, in each of which the volunteers received either a test drug (nirmatrelvir at the dose of 300 mg) in combination with ritonavir (100 mg), or a reference drug (a combination of nirmatrelvir 300 mg and ritonavir 100 mg), given as a single dose. A wash-out period between each of the administrations was 7 days. The blood sampling to determine the concentration of nirmatrelvir was carried out in the range from 0 to 36 h in each of the study periods. A nirmatrelvir concentration was determined by a validated HPLC-MS/MS method with a lower quantitation limit of 10 ng/mL. Bioequivalence was assessed by comparing 90% confidence intervals (CIs) for the ratio of geometric means of AUC(0-36) and Cmax of the test drug and reference drugs with the established equivalence limits of 80.00-125.00%.Results. In the study were included 68 healthy volunteers, 67 participants of which were included in the bioequivalence population. The pharmacokinetic parameters of the drugs were comparable to each other. The 90% confidence interval for the ratio of the geometric mean of the maximum drug concentration in the blood plasma and the area under the pharmacokinetic curve << concentration-time >> from zero to the last blood draw within 36 hours of nirmatrelvir was 87.26-100.83 and 93.27-103.74%, which meets the criteria for assessing bioequivalence. The test drugs were well tolerated by the volunteers. The incidence of adverse events was similar for the test and reference drugs. No serious adverse events were recorded during the entire study.Conclusion. As a result of this study, bioequivalence of the test and reference drugs has been established.

Burden of respiratory coinfections in haematology patients with COVID-19

Introduction: Following the lifting of generalised restrictions and universal masking, severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2)- infected patients, especially the clinically extremely vulnerable (CEV) haematology patients, are at an increased risk for other respiratory viral coinfections;therefore, physicians need to be cognizant about excluding other treatable respiratory pathogens. Here, we report coinfection with SARS-CoV- 2 and other respiratory pathogens in patients with haematological cancers presenting to a large tertiary care hospital. Method(s): From July 2022-December 2022, patients with haematological disorders were screened for SARS-CoV- 2 and other 10 common respiratory pathogens by PCR. We performed a retrospective analysis of patients with concurrent respiratory viruses and will prospectively evaluate the same from Jan 2023 to March 2023. Result(s): During this period a total of 322 inpatients had routine screening and additional 6213 swabs were done in the outpatient/ambulatory setting, of which 294 were positive in 221 patients. We excluded all patients who had a single positive PCR swab result and specifically analysed only patients with coinfections. We identified 30 patients (14%) who had respiratory coinfections with 73 viral infections/reactivations over 6 months period, which represented 25% of all positive swabs: 25 inpatients (19 symptomatic/6 asymptomatic) and 48 in outpatients (32 symptomatic/16 asymptomatic). The median age of the cohort was 47.3 years (21-77). Patients were post allograft (n = 15), autograft (n = 7), post CART (n = 5) and postchemotherapy (n = 4). Of the 30 cases, 13 patients had concurrent infections: 5 SARS-CoV2, 10 Respiratory syncytial virus (RSV), 7 Rhino and 4 Influenza A, with all patients having dual viral infection. The remaining 17 patients had multiple viral infections but separated by a median of 54 days (range 27-137 days): 16 SARS-CoV2, 5 RSV, 6 Rhino, 2 Parainfluenza, 2 Adeno and one each of Influenza A, Influenza B, and metapneumovirus. Of the treatable infections (n = 46), 22% were detected on routine asymptomatic swabbing, with 50% of SARS-CoV2 detected on routine swabs. All 8 patients with Influenza were treated with oseltamivir, of 16 RSV cases one was treated with oral ribavirin and of the 22 SARS-CoV2 patients, 5 were treated (4 Paxlovid and 1 Remdesivir). No patients needed intensive care support and no deaths were reported. Conclusion(s): The burden of respiratory coinfections in CEV cohort has a significant impact on respiratory isolation and management, including appropriate & timely initiation of therapy for treatable viral infections. Although mortality was not increased secondary to respiratory coinfections and none needed intensive care, larger prospective cohorts are needed to assess the exact impact.

COVID-19 pre-exposure prophylaxis with tixagevimab/cilgavimab in patients with haematological malignancy: A single-centre experience

Background: COVID-19 pandemic still pose a substantial threat worldwide despite increasing vaccine availability. Patients with haematological malignancies have been shown to have increased risk of contracting COVID-19 and are more susceptible to develop severe illness from SARS-CoV- 2 infection. The immune response to vaccines is impaired in patients with haematological malignancy due to underlying disease or antineoplastic therapies. The monoclonal-antibody combination, Evusheld is composed of tixagevimab and cilgavimab, two neutralising antibodies against SARS-CoV- 2. It has been shown to be safe and have efficacy for the prevention of COVID-19. Our aim of study is to describe the incidence and outcome of breakthrough COVID-19 infection among patients who received Evusheld in our centre and analyse the factors that possibly increase the risk of breakthrough infection. Material(s) and Method(s): A retrospective review of all adult patients with haematological malignancy who received tixagevimab/ cilgavimab 150/150 mg injection in Hospital Pulau Pinang from 1 July 2022 to 31 August 2022 with a follow-up period to 30 November 2022 was conducted. Demographic data, clinical characteristics and outcome will be retrieved from patient's medical records. Data were analysed using Statistical Package for Social Sciences software (version 21.0). Result(s): A total of 96 patients (50 males and 46 females) received tixagevimab/cilgavimab injection during the study period with a median age of 61 years (range 19-82). Majority of them were diagnosed with multiple myeloma (42.7%), followed by lymphoma (33.3%) and leukaemia (24%). One third of them had history of therapy with monoclonal antibody and 20% had haematopoietic stem cell transplantation. No major adverse effects of tixagevimab/cilgavimab injection were noted among the study population. Of the 12 patients (12.5%) who had COVID-19 infection, all of them had mild infection;three were asymptomatic and six patients received Paxlovid antiviral therapy. The median time from tixagevimab/cilgavimab to the onset of COVID-19 infection was 35 days (range 5-97 days). The mean age of patients with breakthrough COVID-19 infection were older compared to those without breakthrough infection but was not statistically significant. The incidence of breakthrough COVID-19 infection was not affected by type of haematological malignancy, history of monoclonal antibody therapy or COVID-19 vaccination. Discussion and Conclusion(s): Our findings showed that tixagevimab/cilgavimab was safe and effective in preventing COVID-19- related morbidity and mortality among patients with haematological malignancy during the study period. However, the limitation is the lack of access to whole genome sequencing for detection of resistant variants for breakthrough infections.

Safety of Pharmacotherapy in COVID-19 Patients: A Literature Review.

The safety of COVID-19 pharmacotherapy is a relevant issue, first of all, because of the current lack of experience with using particular medicinal products and with off-label prescribing. The aim of the study was to analyse information on potential adverse drug reactions (ADRs) and their predictors in etiology- and pathogenesis-oriented COVID-19 therapy. According to literature data, the main clinically significant risk factors for COVID-19 patients to develop an ADR are the duration of their hospital stay, combined use of antivirals, polypharmacy, and their history of drug allergies. The most common adverse reactions to antivirals, to virus-neutralising antibodies, and to human anti-COVID-19 immunoglobulin and convalescent plasma are, respectively, gastrointestinal and hepatobiliary disorders;gastrointestinal disorders, neurological disorders, and allergic reactions;and transfusion reactions (fever, chills, etc.). For pathogenesis-oriented therapy with systemic glucocorticosteroids, the most characteristic ADR is hyperglycaemia. Janus kinase inhibitors and interleukin inhibitors are most often associated with gastrointestinal disorders and hypertransaminasemia;neutropenia is also characteristic of a number of interleukin inhibitors. Haemostatic adverse reactions to anticoagulants depend on the patient's dosing regimen and condition. Drug-drug interactions are a common problem in COVID-19 treatment, with the combination of nirmatrelvir and ritonavir showing the largest number of significant interactions attributed to their pharmacokinetics. Currently, there is data on the role of pharmacogenetic biomarkers in the safety and clinical outcomes of COVID-19 therapy. Thus, to improve the safety of COVID-19 therapy, an integrated approach is needed that will take into account both the clinical, demographic, and pharmacogenetic predictors of ADRs and the risk of drug-drug interactions.Copyright © 2023 Safety and Risk of Pharmacotherapy. All rights reserved.

Mild COVID-19 outcomes in adults with inborn errors of immunity: a single-center experience

Currently, 640 million cases of coronavirus disease 2019 (COVID-19) and 6.6 million deaths have been reported world-wide. Risk factors for severe COVID-19 are known, including those with compromised immunity. Among patients with inborn errors of immunity (IEI), early reports of severe outcomes lead to strict masking and social distancing measures. While this resulted in relatively low infection rates among those with IEI, real-world data describing the clinical course of COVID-19 in this patient population have remained limited. We performed a retrospective study of adult IEI patients followed by our center in which a positive test (rapid antigen or PCR) for COVID-19 was determined between November 2021-November 2022. Medical charts were reviewed, and patient interviews conducted. All patients provided informed consent. Twenty-nine patients were enrolled (22 females, 7 males), aged between 18-69 years (median: 20-29 years). The cohort included those with antibody deficiencies (41.37%), combined immunodeficiencies (34.48%;HIES, CARD11, STAT1-GOF), immune dysregulation disorders (20.69%;LRBA deficiency, AIRE deficiency) and phagocyte defect (3.45%;CGD). The duration of symptoms ranged between 3 days-4 weeks (median: < 1 week). Upper respiratory symptoms (including sore throat, congestion) were reported in 97% while fever was present in 41% of patients. Prior to infection, 14 (48%) patients had underlying asthma or bronchiectasis - 2 subsequently experienced shortness of breath and were treated with inhalers or Sotrovimab, respectively. No treatment was required in 65.5% of cases. The remaining received Paxlovid (10.3%), Sotrovimab (13.79%), or antibiotics (10.3%). Of the 2 patients with STAT1-GOF, one tested positive during a repeat episode of febrile neutropenia which required hospitalization. No other patients were hospitalized or needed ICU admission. No deaths were recorded. In light of these favourable outcomes, patients with IEI can gradually and safely return to normal activities.Copyright © 2023 Elsevier Inc.

Cost-Effectiveness Analysis of Nonpharmaceutical Interventions Combined with Inactivated Vaccination and Oral Medicine in China

Objectives: Various interventions were used to control the COVID-19 pandemic and protect population health, including vaccination, medication and nonpharmaceutical interventions (NPIs). This study aims to examine the cost-effectiveness of different combinations of NPIs (including social distancing, mask wearing, tracing-testing-isolation, mass testing, and lockdown), oral medicine (Paxlovid), and vaccination (including two-dose and three-dose vaccination) under the Delta and Omicron pandemic in China. Method(s): We constructed a Markov model using a SIRI structure with a one-week cycle length over one-year time horizon to estimate the cost-effectiveness of different combinations in China from societal perspective. Effectiveness of interventions, disease transition probabilities and costs were from published data, quality-adjusted life years (QALYs) gained and incremental cost-effectiveness ratios (ICER) and net monetary benefits were calculated for one-year time horizon. One-way and probabilistic sensitivity analyses were performed to test the robustness of the model. Scenario analysis was developed to examine different situations under the Omicron pandemic. Result(s): Under the Delta pandemic, implementing the combination of social distancing, mask wearing, mass testing and three-dose vaccination was the optimal strategy, with cost at $11165635.33 and utility of 94309.94 QALYs, and had 60% probability of being cost-effective compared with other strategies. Three-dose vaccination combinations were better than two-dose combinations. Under the Omicron pandemic, antigen testing was better than nucleic testing by avoiding cross infections;second, adding Paxlovid or lockdown to the combined intervention strategies could increase limited health outcomes at huge cost and thus were not cost-effective;last, encouraging patients to stay at home can save societal costs compared with concentrated quarantine at hospitals. Conclusion(s): Three-dose vaccination and self-quarantine of asymptomatic and mild cases can save total costs. Under the Omicron pandemic outbreak, antigen testing is a better way to control the pandemic, and adding Paxlovid or lockdown to intervention combinations is not cost-effective.Copyright © 2023

Paxlovid Prophylaxis or Treatment in Pregnancy: Data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry

Background: The US Food and Drug Administration under an Emergency Use Authorization approved use of Paxlovid (nirmatrelavir and ritonavir) for the treatment of mild-to-moderate COVID-19 in adults and children with a positive test for SARS-Co-2 and who are at high risk for progression to severe COVID-19. Pregnant women are at increased risk of severe complications resulting from COVID-19 infection;however, minimal data on the safety of Paxlovid in human pregnancy are available. Objective(s): The objectives of this study are to assess risks of major congenital malformations, spontaneous abortion, elective termination, stillbirth, preterm delivery, small for gestational age infants at birth, or infants who were small for age at one year in pregnancies/infants prenatally exposed to Paxlovid in pregnancy compared to individuals who did not receive this treatment. Design(s): This study involves prospective data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry which enrolls pregnant women residing in the US or Canada and captures data through maternal interviews and ion of medical records. Result(s): Among pregnant women participating in the OTIS Pregnancy Registry as of February 1, 2023, 59 reported exposure to Paxlovid in pregnancy;25.4% exposed within 30 days prior to the last menstrual period and through the first trimester, 42.4% exposed in second trimester, and 32.2% exposed in the third trimester. As of January 2023, 17 of those enrolled have completed pregnancy outcomes. One was lost to follow-up. Of the remainder, there were no adverse pregnancy outcomes reported. Conclusion(s): Very limited data are available on this potentially beneficial treatment in pregnancy. To date, no serious signals for this exposure have been detected.

Molnupiravir and combination of nirmatrelvir and ritonavir (PaxlovidTM) - oral anti-viral drugs in COVID-19: a systematic review

The COVID-19 pandemic situation demands the discovery of newer drugs and/ or repurposing of the existing drugs. The anti-viral drugs approved for COVID-19 are remdesivir and favipiravir. Two more directly acting oral anti-viral drugs have been granted Emergency Use Authorization by US-FDA, molnupiravir on December 23, 2021, and nirmatrelvir and ritonavir (PaxlovidTM) on December 22, 2021. Molnupiravir, an RNA-dependent RNA polymerase (RdRp) inhibitor, has also been approved in the UK and is under review with other regulatory agencies. PaxlovidTM (a combination of the new anti-viral drugs nirmatrelvir and ritonavir) has been developed and approved by US-FDA and CDSCO, India. Nirmatrelvir acts by inhibiting 3CL (chymotrypsin-like) protease enzyme and it is combined with ritonavir to slow down its breakdown by cytochrome P450 enzymes and to increase the bioavailability. Both molnupiravir and PaxlovidTM have been approved for mild and moderate COVID-19 and in patients who have a higher risk of disease progression to severe disease including hospitalisation and death. This article systematically reviews the clinical trials of molnupiravir and PaxlovidTM that evaluated their efficacy and safety against COVID-19 in both published and unpublished literature.

Clinical efficacy of nirmatrelvir and ritonavir combination for treating diabetic patients with COVID-19.

The aim of this study was to investigate the clinical efficacy of a combination of nirmatrelvir and ritonavir (NMV-r) for treating COVID-19 in patients with diabetes mellitus (DM). This retrospective cohort study used the TriNetX research network to identify adult diabetic patients with COVID-19 between January 1, 2020, and December 31, 2022. Propensity score matching was used to match patients who received NMV-r (NMV-r group) with those who did not receive NMV-r (control group). The primary outcome was all-cause hospitalization or death during the 30-day follow-up period. Two cohorts comprising 13 822 patients with balanced baseline characteristics were created using propensity score matching. During the follow-up period, the NMV-r group had a lower risk of all-cause hospitalization or death than the control group (1.4% [n = 193] vs. 3.1% [n = 434]; hazard ratio [HR], 0.497; 95% confidence interval [CI], 0.420-0.589). Compared with the control group, the NMV-r group also had a lower risk of all-cause hospitalization (HR, 0.606; 95% CI, 0.508-0.723) and all-cause mortality (HR, 0.076; 95% CI, 0.033-0.175). This lower risk was consistently observed in almost all subgroup analyses, which examined sex (male: 0.520 [0.401-0.675]; female: 0.586 [0.465-0.739]), age (age 18-64 years: 0.767 [0.601-0.980]; ≥65 years: 0.394 [0.308-0.505]), level of HbA1c (<7.5%: 0.490 [0.401-0.599]; ≥7.5%: 0.655 [0.441-0.972]), unvaccinated (0.466 [0.362-0.599]), type 1 DM (0.453 [0.286-0.718]) and type 2 DM (0.430 [0.361-0.511]). NMV-r can help reduce the risk of all-cause hospitalization or death in nonhospitalized patients with DM and COVID-19.

Paxlovid-Induced Symptomatic Bradycardia and Syncope.

Paxlovid (nirmatrelvir/ritonavir) is a game changer in the fight against COVID-19 due to its ease of administration and significant benefits of reducing progression to severe COVID-19, hospitalization, and death. Cardiac adverse events such as bradycardia and syncope are not known with this medication. We report a case of a 71-year-old patient who developed symptomatic bradycardia, syncopal episodes, and sinus pause after taking Paxlovid. Discontinuing medication and intravenous atropine helped to reverse the bradycardia and symptoms promptly. She did not require a pacemaker. We would like to report this possible association between Paxlovid and bradycardia. Until further information or studies are available, it is advised to promptly discontinue Paxlovid after any evidence of bradycardia and closely monitor for at least 40 hours in a hospital setting. The reported half-life (t 1/2) of the medication is 6.05 ± 1.79 hours and using 8 hours as a reference for the upper limit of t 1/2, around 97 % of the medication should be cleared off in about 40 hours (five half-lives).

Oral anti-viral therapy for early COVID-19 infection in patients with haematological malignancies: A multicentre prospective cohort.

High rates of lung failure have been reported in haematological patients after SARS-CoV2 infection. An early administration of monoclonal antibodies or anti-virals may improve the prognosis. Oral anti-virals may have a wider use independently of the genetic variations of the virus. Prospective data on anti-virals in haematological malignancies (HMs) are still lacking. Outpatients diagnosed with HM and early COVID-19 infection were prospectively treated with the oral anti-virals nirmatrelvir/ritonavir and molnupiravir. Incidence of lung failure, deaths and adverse events was analysed. Long-term outcome at third month was evaluated. Eighty-two outpatients were evaluable for the study objectives. All patients had been treated for their HM within 12 months. COVID-19-related lung failure was 23.1%. Active HM (aOR = 4.42; p = 0.038) and prolonged viral shedding (aOR = 1.04; p = 0.022) resulted independent predictors of severe infection. The vaccination with three to four doses (aOR = 0.02; p = 0.001) and with two doses (aOR = 0.06; p = 0.006) resulted protective. COVID-19-related deaths at 28 days were 6.1%. All-cause mortality at 90-day follow-up was 13.4% (n. 11) and included opportunistic infections and cardiovascular events. In conclusion, this approach reduced the incidence of lung failure and specific mortality compared to previous cohorts, but patients remain at high risk of further complications.

Nirmatrelvir/Ritonavir for hemodialysis patients with COVID-19.

Background: Hemodialysis patients have a high risk of severe/critical COVID-19 and related high mortality, but nirmatrelvir/ritonavir is not recommended for hemodialysis patients with COVID-19 infection because of lack of evidence of safety. Objectives: Our study aims to evaluate the minimum plasma concentration (Cmin) of nirmatrelvir and its safety of different doses of nirmatrelvir/ritonavir in hemodialysis patients with mild COVID-19. Method: This was a prospective, two step, nonrandomized, open-label study. Participants were treated with nirmatrelvir 150 mg or 300 mg once a day (another 75 mg or 150 mg supplied after hemodialysis) and ritonavir 100 mg twice daily for 5 days, respectively. The primary outcome was the safety of nirmatrelvir/ritonavir, including the Cmin of nirmatrelvir and the number of adverse events (AE). The secondary outcome was the time of viral elimination in hemodialysis patients. Results: Adverse events were happened in 3 and 7 participants in the step 1 and step 2 group, respectively (p = 0.025). Among them, 2 and 6 participants were identified as drug-related adverse events (p = 0.054). No SAE or liver function damage happened. The Cmin of nirmatrelvir in step 1 and step 2 group were 5,294.65 ± 2,370.59 ng/mL and 7,675.67 ± 2,745.22 ng/mL (p = 0.125). The Cmin of the control group was 2,274.10 ± 1,347.25 ng/mL (p = 0.001 compared to step 2 and p = 0.059 compared to step 1). Compared to hemodialysis patients without nirmatrelvir/ritonavir, there were no statistical differences in overall viral elimination time (p = 0.232). Conclusion: In our study, two doses of nirmatrelvir/ritonavir appeared to be excessive for hemodialysis patients. Although all of the patients tolerated 5-day administration, nearly half of the patients experienced drug-related adverse events. In addition, the medication group did not show a significant advantage in the time of viral elimination.

Efficacy of Sotrovimab (SOT), Molnupiravir (MOL), and Nirmatrelvir/Ritponavir (N/R) and Tolerability of Molnupiravir in Outpatients at High Risk for Severe COVID-19.

OBJECTIVE: The main goal of this study was to assess the potential clinical impact of an outpatient administration of available antivirals including SOT, N/R, and MOL to COVID-19 patients at high risk for disease progression. METHODS: We conducted a retrospective analysis on 2606 outpatient individuals with mild to moderate COVID-19 at risk for disease progression, hospitalization, or death. After receiving either SOT (420/2606), MOL (1788/2606), or N/R (398/2606), patients were followed-up with regarding primary (hospitalization rate) and secondary (treatment and side effects) outcomes by phone. RESULT: A total of 2606 patients were treated at the outpatient clinic (SOT: 420; N/R: 398; MOL: 1788). 3.2% of the SOT patients (1 ICU admission), 0.8% of the MOL patients (2 ICU admissions), and none of the N/R patients were hospitalized. 14.3% of the N/R patients reported strong to severe side effects, exceeding SOT (2.6%) and MOL (5%) patients. A reduction in COVID symptoms after the treatment was experienced by 43% of patients in both the SOT and MOL groups and by 67% of patients in the N/R group, respectively. Women had a higher chance of symptom improvement with MOL (OR 1.2, 95%CI 1.0-1.5). CONCLUSION: All antiviral treatment options effectively prevented hospitalization in high-risk COVID-19 patients and were well tolerated. Side effects were pronounced in patients with N/R.

Estimation of Intangible Costs for Factors Associated with Oral Antiviral Drugs for COVID-19 Treatment: A Conjoint Analysis in Japan.

INTRODUCTION: During the recent coronavirus disease 2019 (COVID-19) pandemic, preferences for factors associated with vaccines have been evaluated. Three oral antiviral drugs have been approved in Japan for patients with mild-to-moderate I COVID-19 symptoms. Although preferences for the drugs may also depend on various factors, these have not been fully evaluated. METHODS: A conjoint analysis was performed based on an online survey in August 2022 to estimate the intangible costs of factors associated with oral antiviral drugs for COVID-19. Respondents were individuals aged 20-69 across Japan. The attributes included the company (Japanese/foreign) that developed the drug, formulation and size of the drug, frequency of administration per day, number of tablets/capsules per dose, number of days until no longer infectious to others, and out-of-pocket expenses. A logistic regression model was applied to estimate the utility of each level for each attribute. The intangible costs were calculated by comparing the utility to the out-of-pocket attribute. RESULTS: Responses were collected from 11,303 participants. The difference between levels was the largest for companies that developed a drug; the intangible costs were JPY 5390 higher for the foreign company than for the Japanese company. The next largest difference was in the number of days until one is no longer infectious. For the same formulation, the intangible cost was lower for small sizes than large sizes. For similar-sized tablets and capsules, the intangible cost was lower for tablets than capsules. These tendencies were similar regardless of COVID-19 infection history and the presence of risk factors for severe COVID-19 in the respondents. CONCLUSION: Intangible costs for factors associated with oral antiviral drugs among the Japanese population were estimated. The results may change as the number of people with a history of COVID-19 infection increases and significant progress is made regarding treatments.

Molnupiravir, Nirmatrelvir/Ritonavir, or Sotrovimab for High-Risk COVID-19 Patients Infected by the Omicron Variant: Hospitalization, Mortality, and Time until Negative Swab Test in Real Life.

Background. Several drugs which are easy to administer in outpatient settings have been authorized and endorsed for high-risk COVID-19 patients with mild-moderate disease to prevent hospital admission and death, complementing COVID-19 vaccines. However, the evidence on the efficacy of COVID-19 antivirals during the Omicron wave is scanty or conflicting. Methods. This retrospective controlled study investigated the efficacy of Molnupiravir or Nirmatrelvir/Ritonavir (Paxlovid®) or Sotrovimab against standard of care (controls) on three different endpoints among 386 high-risk COVID-19 outpatients: hospital admission at 30 days; death at 30 days; and time between COVID-19 diagnosis and first negative swab test result. Multivariable logistic regression was employed to investigate the determinants of hospitalization due to COVID-19-associated pneumonia, whereas time to first negative swab test result was investigated by means of multinomial logistic analysis as well as Cox regression analysis. Results. Only 11 patients (overall rate of 2.8%) developed severe COVID-19-associated pneumonia requiring admission to hospital: 8 controls (7.2%); 2 patients on Nirmatrelvir/Ritonavir (2.0%); and 1 on Sotrovimab (1.8%). No patient on Molnupiravir was institutionalized. Compared to controls, hospitalization was less likely for patients on Nirmatrelvir/Ritonavir (aOR = 0.16; 95% CI: 0.03; 0.89) or Molnupiravir (omitted estimate); drug efficacy was 84% for Nirmatrelvir/Ritonavir against 100% for Molnupiravir. Only two patients died of COVID-19 (rate of 0.5%), both were controls, one (a woman aged 96 years) was unvaccinated and the other (a woman aged 72 years) had adequate vaccination status. At Cox regression analysis, the negativization rate was significantly higher in patients treated with both antivirals-Nirmatrelvir/Ritonavir (aHR = 1.68; 95% CI: 1.25; 2.26) or Molnupiravir (aHR = 1.45; 95% CI: 1.08; 1.94). However, COVID-19 vaccination with three (aHR = 2.03; 95% CI: 1.51; 2.73) or four (aHR = 2.48; 95% CI: 1.32; 4.68) doses had a slightly stronger effect size on viral clearance. In contrast, the negativization rate reduced significantly in patients who were immune-depressed (aHR = 0.70; 95% CI: 0.52; 0.93) or those with a Charlson index ≥5 (aHR = 0.63; 0.41; 0.95) or those who had started the respective treatment course 3+ days after COVID-19 diagnosis (aOR = 0.56; 95% CI: 0.38; 0.82). Likewise, at internal analysis (excluding patients on standard of care), patients on Molnupiravir (aHR = 1.74; 95% CI: 1.21; 2.50) or Nirmatrelvir/Ritonavir (aHR = 1.96; 95% CI: 1.32; 2.93) were more likely to turn negative earlier than those on Sotrovimab (reference category). Nonetheless, three (aHR = 1.91; 95% CI: 1.33; 2.74) or four (aHR = 2.20; 95% CI: 1.06; 4.59) doses of COVID-19 vaccine were again associated with a faster negativization rate. Again, the negativization rate was significantly lower if treatment started 3+ days after COVID-19 diagnosis (aHR = 0.54; 95% CI: 0.32; 0.92). Conclusions. Molnupiravir, Nirmatrelvir/Ritonavir, and Sotrovimab were all effective in preventing hospital admission and/or mortality attributable to COVID-19. However, hospitalizations also decreased with higher number of doses of COVID-19 vaccines. Although they are effective against severe disease and mortality, the prescription of COVID-19 antivirals should be carefully scrutinized by double opinion, not only to contain health care costs but also to reduce the risk of generating resistant SARS-CoV-2 strains. Only 64.7% of patients were in fact immunized with 3+ doses of COVID-19 vaccines in the present study. High-risk patients should prioritize COVID-19 vaccination, which is a more cost-effective approach than antivirals against severe SARS-CoV-2 pneumonia. Likewise, although both antivirals, especially Nirmatrelvir/Ritonavir, were more likely than standard of care and Sotrovimab to reduce viral shedding time (VST) in high-risk SARS-CoV-2 patients, vaccination had an independent and stronger effect on viral clearance. However, the effect of antivirals or COVID-19 vaccination on VST should be considered a secondary benefit. Indeed, recommending Nirmatrelvir/Ritonavir in order to control VST in high-risk COVID-19 patients is rather questionable since other cheap, large spectrum and harmless nasal disinfectants such as hypertonic saline solutions are available on the market with proven efficacy in containing VST.

[Translated article] Paradoxical interaction between nirmatrelvir/ritonavir and voriconazole in a patient with COVID-19.

This case is based on a drug interaction between nirmatrelvir/ritonavir (approved drug for COVID-19) and voriconazole is presented, possibly derived from the bidirectional effect of ritonavir on the 2 main voriconazole metabolizing enzymes (cytochrome P450 3A and 2C19) ritonavir inhibits the former and induces the latter respectively. According to the main pharmacotherapeutic information databases, in the interaction between both drugs, a decrease in the area under the curve of voriconazole is expected due to the inducing effect of its metabolism; however, in the case we present, unexpectedly, a paradoxical effect occurs, according to what is described in literature, with the result of sustained supratherapeutic levels of voriconazole. Given the short treatment period with nirmatrelvir/ritonavir (5 days), the induction effect of ritonavir proposed in the studies on which the recommendations are based, where treatment with ritonavir is longer, does not occur.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (PaxlovidTM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Physiologically-Based Pharmacokinetic Modeling of PAXLOVID™ with First-Order Absorption Kinetics.

PURPOSE: PAXLOVID™ is nirmatrelvir tablets co-packaged with ritonavir tablets. Ritonavir is used as a pharmacokinetics (PK) enhancer to reduce metabolism and increase exposure of nirmatrelvir. This is the first disclosure of Paxlovid physiologically-based pharmacokinetic (PBPK) model. METHODS: Nirmatrelvir PBPK model with first-order absorption kinetics was developed using in vitro, preclinical, and clinical data of nirmatrelvir in the presence and absence of ritonavir. Clearance and volume of distribution were derived from nirmatrelvir PK obtained using a spray-dried dispersion (SDD) formulation where it is considered to be dosed as an oral solution, and absorption is near complete. The fraction of nirmatrelvir metabolized by CYP3A was estimated based on in vitro and clinical ritonavir drug-drug interaction (DDI) data. First-order absorption parameters were established for both SDD and tablet formulation using clinical data. Nirmatrelvir PBPK model was verified with both single and multiple dose human PK data, as well as DDI studies. Simcyp® first-order ritonavir compound file was also verified with additional clinical data. RESULTS: The nirmatrelvir PBPK model described the observed PK profiles of nirmatrelvir well with predicted AUC and Cmax values within ± 20% of the observed. The ritonavir model performed well resulting in predicted values within twofold of observed. CONCLUSIONS: Paxlovid PBPK model developed in this study can be applied to predict PK changes in special populations, as well as model the effect of victim and perpetrator DDI. PBPK modeling continues to play a critical role in accelerating drug discovery and development of potential treatments for devastating diseases such as COVID-19. NCT05263895, NCT05129475, NCT05032950 and NCT05064800.

Pharmacophore Oriented MP2 Characterization of Charge Distribution for Anti-SARS-CoV-2 Inhibitor Nirmatrelvir.

Quantum mechanical second order Møller-Plesset (MP2) perturbation theory and density functional theory (DFT) Becke, 3-parameter, Lee-Yang-Parr (B3LYP) and Minnesota 2006 local functional (M06L) calculations were performed to optimize structure of nirmatrelvir and compute the Merz-Kollman electrostatic potential (MK ESP), natural population analysis (NPA), Hirshfeld, charge model 5 (CM5), and mulliken partial charges. The mulliken partial charge distribution of nirmatrelvir exhibits a poor correlation with the MK ESP charges in MP2, B3LYP, and M06L calculations respectively. The NPA, Hirshfeld, and CM5 partial charge scheme of nirmatrelvir indicate a reasonable correlation with MK ESP charge assignments in B3LYP and M06L calculations. The above correlations were not improved by the inclusion of implicit solvation model. The MK ESP and CM5 partial charges show a strong correlation between the results of MP2 and two DFT methods. The three optimized structures present a certain degree of differences from the crystal bioactive conformation of nirmatrelvir, suggesting the nirmatrelvir-enzyme complex is formed in the induced-fit model. The Reactivity of warhead electrophilic nitrile is justified by the relatively weaker strength of π bonds in the MP2 calculations. The nirmatrelvir hydrogen bond acceptors consistently show strong delocalization of lone pair electrons in three calculations, whereas hydrogen bond donors are found to have high polarization on the heavy nitrogen atoms in MP2 computations. This work helps to parametrize the force field of nirmatrelvir and improve accuracy of molecular docking and rational inhibitor design.