Real-world data on long-acting intramuscular maintenance therapy with cabotegravir and rilpivirine mirror Phase 3 results.

INTRODUCTION: Cabotegravir, an integrase strand transfer inhibitor, and rilpivirine, an NNRTI, constitute the first long-acting (LA), injectable, two-drug ART regimen approved for the maintenance of virological suppression in persons living with HIV-1 (PLHIV). The aim of this study was to assess clinical effectiveness and tolerability of LA cabotegravir/rilpivirine in a real-world setting. PATIENTS AND METHODS: We conducted a retrospective, single centre study, including all PLHIV receiving LA cabotegravir/rilpivirine as standard-of-care in our tertiary centre even if initiated in clinical trials. RESULTS: Between 2014 and 2022, 126 PLHIV initiated LA cabotegravir/rilpivirine. All were ART-experienced, and 98.4% had a viral load (VL) of <50 copies/mL before LA cabotegravir/rilpivirine initiation. Median BMI at cabotegravir/rilpivirine initiation was 24 IQR (23-28). During a median follow-up of 9 months IQR (7-24), 27 patients discontinued cabotegravir/rilpivirine because of virological failure, 6 for adverse events, 11 for personal reasons unrelated to treatment tolerance and 5 for other reasons. Virological failure was not associated with a higher BMI, nor with weight gain during LA intramuscular (IM) cabotegravir/rilpivirine treatment, inadequate cabotegravir and rilpivirine concentrations, VL blips or the use of oral lead-in (OLI) or not. No drug resistance-associated mutation emerged. Adverse events leading to treatment interruption were injection-site pain (n = 3) and neuropsychological side effects (n = 3). A correlation between BMI and both cabotegravir and rilpivirine concentrations at 1 month post-initiation of LA-IM cabotegravir/rilpivirine was observed, with no impact of OLI. CONCLUSIONS: Data from this real-world cohort of PLHIV who received cabotegravir/rilpivirine LA injections suggest that this regimen is effective and well tolerated. Virological failures were not associated with the acquisition of resistance mutations.

Immuno-virological and Clinical Follow-up of Persons Living With HIV-2 (PWHIV-2) Receiving Bictegravir/Emtricitabine/Tenofovir Alafenamide Fumarate (BIC/FTC/TAF): A Retrospective Study.

This retrospective study evaluated Bictegravir/FTC/TAF in 24 PWHIV, 5 naive and 19 pretreated. After a median follow-up of 37.5 months, all PWHIV-2 had a plasma viral load < 40 copies/mL. Median CD4 count increased significantly from 580 to 625 cells/mm3, suggesting the effectiveness of Bictegravir/FTC/TAF to treat HIV-2 infection.

Preclinical in vivo assessment of the activity of AZD7442 anti-SARS-CoV-2 monoclonal antibodies against Omicron sublineages.

Therapeutic monoclonal antibodies have been successful in protecting vulnerable populations against SARS-CoV-2. However, their effectiveness has been hampered by the emergence of new variants. To adapt the therapeutic landscape, health authorities have based their recommendations mostly on in vitro neutralization tests. However, these do not provide a reliable understanding of the changes in the dose-effect relationship and how they may translate into clinical efficacy. Taking the example of EvusheldTM (AZD7442), we aimed to investigate how in vivo data can provide critical quantitative results and project clinical effectiveness. We used the Golden Syrian hamster model to estimate 90 % effective concentrations (EC90) of AZD7442 in vivo against SARS-CoV-2 Omicron BA.1, BA.2 and BA.5 variants. While our in vivo results confirmed the partial loss of AZD7442 activity for BA.1 and BA.2, they showed a much greater loss of efficacy against BA.5 than that obtained in vitro. We analyzed in vivo EC90s in perspective with antibody levels measured in a cohort of immunocompromised patients who received 300 mg of AZD7442. We found that a substantial proportion of patients had serum levels of anti-SARS-CoV-2 spike protein IgG above the estimated in vivo EC90 for BA.1 and BA.2 (21 % and 92 % after 1 month, respectively), but not for BA.5. These findings suggest that AZD7442 is likely to retain clinical efficacy against BA.2 and BA.1, but not against BA.5. Overall, the present study illustrates the importance of complementing in vitro investigations by preclinical studies in animal models to help predict the efficacy of monoclonal antibodies in humans.

Clinical characteristics and outcomes of respiratory syncytial virus-associated ARF in immunocompetent patients: A seven-year experience at a tertiary hospital in France.

BACKGROUND: Respiratory syncytial virus (RSV) is widely recognized as a cause of acute respiratory failure in infants and immunocompromised patients. However, RSV can also contribute to acute respiratory failure in adults, particularly among the elderly population. The objective of this study was to analyze the clinical characteristics and outcomes of immunocompetent adults hospitalized for RSV infection. METHODS: This retrospective study included all immunocompetent adult patients consecutively admitted to a tertiary care hospital with RSV-related acute respiratory failure over a seven-year period (2016-2023). Diagnosis of RSV infection was made through nasal swabs or pulmonary samples, with multiplex reverse transcription polymerase chain reaction (RT-PCR). Patients were eligible for inclusion if they required supplemental oxygen therapy for at least 48 h. RESULTS: One hundred and four patients met the inclusion criteria. Median age [IQR] was 77 years [67-85]. Ninety-seven patients had at least one comorbidity (97/104, 93%). At the time of RSV diagnosis, 67 patients (67/104, 64%) experienced acute decompensation of a pre-existing chronic comorbidity. Antibiotics were started in 80% (77/104) of patients; however, only 16 patients had a confirmed diagnosis of bacterial superinfection. Twenty-six patients needed ventilatory support (26/104, 25%) and 21 were admitted to the intensive care unit (21/104, 20%). The median duration of oxygen therapy [IQR] was 6 days [3-9], while the median hospital length of stay [IQR] was 11 days [6-15]. The overall mortality rate within 1 month of hospital admission was 13% (14/104). The sole variables associated with one-month mortality were age and maximum oxygen flow during hospitalization. CONCLUSION: RSV-associated acute respiratory failure affected elderly individuals with multiple comorbidities and was associated with prolonged hospitalization and a high mortality rate.

Salvage Therapy Including Foscarnet and Ibalizumab for Multidrug-Resistant Human Immunodeficiency Virus Type 2 Infection.

We evaluated Ibalizumab (IBA)-containing standardized optimized salvage regimen (with or without a 4-week foscarnet induction) in individuals harboring multidrug-resistant human immunodeficiency virus type 2 (HIV-2). Nine were included; 2 achieved virological suppression after foscarnet induction with a sustained suppression at Week 24 after IBA initiation, and an additional individual at Week 24 after Ibalizumab initiation.

Cardiac Adverse Events and Remdesivir in Hospitalized Patients With COVID-19: A Post Hoc Safety Analysis of the Randomized DisCoVeRy Trial.

BACKGROUND: We aimed to evaluate the cardiac adverse events (AEs) in hospitalized patients with coronavirus disease 2019 (COVID-19) who received remdesivir plus standard of care (SoC) compared with SoC alone (control), as an association was noted in some cohort studies and disproportionality analyses of safety databases. METHODS: This post hoc safety analysis is based on data from the multicenter, randomized, open-label, controlled DisCoVeRy trial in hospitalized patients with COVID-19. Any first AE that occurred between randomization and day 29 in the modified intention-to-treat (mITT) population randomized to either remdesivir or control group was considered. Analysis was performed using Kaplan-Meier survival curves, and Kaplan-Meier estimates were calculated for event rates. RESULTS: Cardiac AEs were reported in 46 (11.2%) of 410 and 48 (11.3%) of 423 patients in the mITT population (n = 833) enrolled in the remdesivir and control groups, respectively. The difference between both groups was not significant (hazard ratio [HR], 1.0; 95% confidence interval [CI], .7-1.5; P = .98), even when serious and nonserious cardiac AEs were evaluated separately. The majority of reports in both groups were of arrhythmic nature (remdesivir, 84.8%; control, 83.3%) and were associated with a favorable outcome. There was no significant difference between the two groups in the occurrence of cardiac AE subclasses, including arrhythmic events (HR, 1.1; 95% CI, .7-1.7; P = .68). CONCLUSIONS: Remdesivir treatment was not associated with an increased risk of cardiac AEs compared with control in patients hospitalized with moderate or severe COVID-19. These results are consistent with other randomized, controlled trials and meta-analyses. Clinical Trials Registration. NCT04315948; EudraCT 2020-000936-23.

Enterococcal endocarditis management and relapses.

Introduction: Enterococcus faecalis is the third micro-organism causing endocarditis and is associated with a significant relapse rate. The objective of this study was to describe the management of patients with Enterococcus faecalis endocarditis (EE) and its implication for relapses. Methods: We conducted a monocentric, retrospective analysis of all patients hospitalized for EE including endocarditis or infection of cardiac implantable electronic device defined by the modified ESC 2015 Duke criteria in a referral centre in Paris, France. Results: Between October 2016, and September 2022, 54 patients with EE were included, mostly men (n = 40, 74%) with a median age of 75 [68-80] years. A high risk for infective endocarditis (IE) was found in 42 patients (78%), including 14 (26%) previous histories of IE, and 32 (59%) histories of valvular cardiac surgery. The aortic valve was the most frequently affected (n = 36, 67%). Combination therapy was mainly amoxicillin-ceftriaxone during all the curative antibiotic therapy duration (n = 31, 57%). Surgery was indicated for 40 patients (74%), but only 27 (50%) were operated on, mainly due to their frailty. Among the 17 deaths (32%), six (11%) happened during the first hospitalization for EE. A suppressive antibiotic treatment was initiated in 15 (29%) patients, mostly because of not performing surgery. During the 6-year study period an EE relapse occurred in three (6%) patients. Conclusions: EE is a worrying disease associated with a high risk of relapse and significant mortality. Suppressive antibiotic therapy could be a key treatment to limit the occurrence of relapses.

[Updates in HIV infection therapeutics]. / Actualités thérapeutiques dans l'infection par le VIH.

UPDATES IN HIV INFECTION THERAPEUTICS. Human immunodeficiency virus (HIV) is still a world public health challenge, with constant therapeutic innovations involved. Very efficient treatments, with a high impact on HIV morbimortality, are now used in routine. Therefore, the new challenges focus on transmission prevention, side effects reduction and quality-of-life improvement. Therapeutic news in the management of patients living with HIV is varied: new molecules, changes in treatment modalities, prevention….

ACTUALITÉS THÉRAPEUTIQUES DANS L'INFECTION PAR LE VIH. L'infection par le virus de l'immunodéficience humaine (VIH) reste en France et dans le monde un problème de santé publique et fait l'objet d'innovations thérapeutiques constantes. Après la réussite des traitements qui ont fait la preuve de leur efficacité en matière de morbi-mortalité liée au VIH, les nouveaux défis sont aujourd'hui tournés vers la prévention de la transmission, la réduction des effets indésirables et l'amélioration de la qualité de vie des patients. Les actualités thérapeutiques dans la prise en charge des patients vivant avec le VIH sont variées : nouvelles molécules, évolution des modalités de traitement, prévention….

Switch to bictegravir/emtricitabine/tenofovir alafenamide from dolutegravir-based therapy.

OBJECTIVE: To evaluate the efficacy and safety of 96 weeks of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) treatment in participants switching from dolutegravir (DTG)-based therapy. DESIGN: Studies 1489 (NCT02607930) and 1490 (NCT02607956) were phase 3 randomized, double-blind, active-controlled, first-line therapy trials in people with HIV-1. After 144 weeks of DTG-based or B/F/TAF treatment, participants could enter a 96-week open-label extension (OLE) of B/F/TAF. METHODS: A pooled analysis evaluated viral suppression (HIV-1 RNA <50 copies/ml) and changes in CD4 + cell count at OLE Weeks 48 and 96, treatment-emergent resistance, safety, and tolerability after switch from a DTG-based regimen to B/F/TAF. Outcomes by prior treatment were summarized using descriptive statistics and compared by two-sided Wilcoxon rank sum test. RESULTS: At OLE Week 96, participants who switched to B/F/TAF ( N  = 519) maintained high levels of virologic suppression (99.5 and 99.1% in those switching from DTG/abacavir/lamivudine and DTG+F/TAF, respectively) and CD4 + cell count, with no treatment-emergent resistance to B/F/TAF. Twenty-one participants experienced drug-related adverse events after switching, with diarrhea, weight gain, and headache occurring most commonly. There were no cases of proximal renal tubulopathy, drug-related Grade 4 adverse events, or serious adverse events. Two participants discontinued B/F/TAF due to treatment-related adverse events. Participants who switched from DTG/abacavir/lamivudine experienced statistically significant greater weight gain than those who switched from DTG+F/TAF; however, median weight change from the blinded phase baseline to OLE Week 96 was numerically similar across treatment groups. CONCLUSION: This medium-term analysis demonstrates the safety and efficacy of switching to B/F/TAF from a DTG-containing regimen in people with HIV-1.

Experiences and challenges with the new European Clinical Trials Regulation.

BACKGROUND: The new European Medicines Agency (EMA) Clinical Trials Information System (CTIS), based on the Clinical Trials Regulation (CTR EU 536/2014), came into full effect on 31 January 2022 and was intended to provide an easier, more streamlined approach to the registration of clinical trials taking place in Europe. Using the experience gained on the new regulatory framework from three multi-national European clinical research studies of outbreak-prone infectious diseases, this article describes the advantages and shortcomings of the new clinical trial submission procedure. METHODS: We report the time to approval, size of the application dossier, and number of requests for information (RFIs) for each study. We also explore the experience of each study within the regulatory framework and its use of CTIS to document the real-world, practical consequences of the system on individual studies. The study assesses the experience of three multi-country studies conducted in Europe working within the EU and non-EU regulatory environments. RESULTS: While the time to regulatory and ethical approval has improved since the implementation of the new regulation, the timelines for approvals are still unacceptably slow, particularly for studies being conducted in the context of an evolving outbreak. Within the new regulatory approval procedure, there is evidence of conflicting application requirements, increased document burden, barriers to submitting important modifications, and debilitating technical hurdles. CONCLUSIONS: CTIS promised to lower the administrative bar, but unfortunately this has not been achieved. There are challenges that need to be urgently confronted and addressed for international research collaborators to effectively manage health crises in the future. While the value of multi-national outbreak research is clear, the limitations and delays imposed by the system, which raise challenging ethical questions about the regulation, are prejudicial to all clinical research, especially publicly funded academic studies. This report is relevant to both regulators and clinical researchers. It is hoped that these findings can help improve pan-European clinical trials, especially for the purpose of epidemic preparedness and response. TRIAL REGISTRATION: This paper references experiences gained during management of three pan-European trials: EU-SolidAct's Bari-SolidAct (CT No. 2022-500385-99-00 - 15 March 2022) and AXL-SolidAct (CT No. 2022-500363-12-00 - 19 April 2022), and MOSAIC (CT No. 2022-501132-42-00 - 22 June 2022).

MOSAIC: A cohort study of human mpox virus disease.

Background: Human mpox is a viral disease caused by an Orthopoxvirus, human mpox virus (hMPXV), typically causing fever and a rash. Mpox has historically been endemic to parts of Central and West Africa, with small numbers of imported cases reported elsewhere, but starting May 2022 an unprecedented global outbreak caused by clade IIb hMPXV was reported outside traditionally endemic countries. This prompted the initiation of MOSAIC, a cohort study implemented in Europe and Asia that aims to describe clinical and virologic outcomes of PCR-confirmed hMPXV disease, including those who receive antiviral therapy. The focus of this article, however, is on describing the study protocol itself with implementation process and operational challenges. Methods: MOSAIC recruits participants of any age with laboratory-confirmed mpox disease who provide informed consent. Participants enrol in the cohort for a total of six months. Blood, lesion and throat samples are collected at several timepoints from the day of diagnosis or the first day of treatment (Day 1) until Day 28 for PCR detection of hMPXV. Clinical data are collected by clinicians and participants (via a self-completion questionnaire) for six months to characterize the signs and symptoms associated with the illness, as well as short- and more long-term outcomes. Discussion: The design and prompt implementation of clinical research response is key in addressing emerging outbreaks. MOSAIC began enrolment within two months of the start of the international mpox epidemic. Enrolment has been stopped and the last follow-up visits are expected in January 2024. ICTRP registration: EU CT number: 2022-501132-42-00 (22/06/2022).

Proportion of APOBEC3-induced defective HIV DNA after 1†year of dolutegravir + lamivudine simplification in the ANRS 167 LAMIDOL trial.

BACKGROUND: Hypermutated viruses induced by APOBEC3 (apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3) proteins comprise some of the defective viruses in the HIV reservoir. Here, we assessed the proportion of APOBEC3-induced defective proviruses in HIV-positive patients before and after receiving dolutegravir + lamivudine dual therapy. METHODS: PBMCs of virologically suppressed patients enrolled in the ANRS 167 LAMIDOL trial, evaluating a switch from triple therapy to dolutegravir + lamivudine, were collected 8 weeks before (W-8) and 48 weeks after (W48) dual-therapy initiation. The Vif and RT regions were subject to next-generation sequencing. Bioinformatic algorithms were developed to identify APOBEC3-defective sequences and APOBEC3-related drug resistance mutations (APOMuts). All hypermutated sequences and those containing at least one stop codon were considered as defective. RESULTS: One hundred and four patients were enrolled (median virological suppression duration: 4.2 years; IQR: 2.0-9.1). Proviral defective reads at W-8 and W48 were detected in Vif in 22% and 29% of patients, respectively, and in RT in 38% and 42% of patients, respectively. At least one APOMut was present in proviruses of 27% and 38% of patients at W-8 and W48, respectively. The ratio of APOMuts/number of potential APOMut sites was significantly higher at W48 (16.5%) than at W-8 (9.8%, P = 0.007). The presence of APOBEC3-defective viruses at W-8 was not associated with HIV total DNA level, nor with the third drug class received prior to switching to dolutegravir + lamivudine, nor with the duration of virological suppression. CONCLUSIONS: Whereas no significant change in the proportion of patients with APOBEC3-defective proviruses was evidenced after 1 year of dolutegravir + lamivudine maintenance, enrichment in APOMuts was observed. Further longer-term studies are needed to assess the other forms of defective viruses with dual-therapy.

Investigating infectious outcomes in adult patients undergoing solid organ transplantation: A retrospective single-center experience, Paris, France.

OBJECTIVES: This study described the demographic characteristics, clinical presentation, treatment, and outcomes of solid organ transplant recipients who were admitted to our center for infection. It also determined factors associated with a poor outcome, and compares early and late period infections. METHODS: In this retrospective observational study, conducted at a tertiary care center in France between October 2017 and March 2019, infectious outcomes of patients with solid organ transplant where studied. RESULTS: A total of 104 patients were included with 158 hospitalizations for infection. Among these 104 patients, 71 (68%) were men. The median age was 59 years old. The most common symptoms on admission were fever (66%) and chills (31%). Lower respiratory tract infections were the most common diagnosis (71/158 hospitalizations). Urinary tract infections were frequently seen in kidney transplant recipients (25/60 hospitalizations). One or more infectious agents were isolated for 113 hospitalizations (72%): 70 bacteria, 36 viruses and 10 fungi, with predominance of gram-negative bacilli (53 cases) of which 13 were multidrug-resistant. The most frequently used antibiotics were third generation cephalosporins (40 cases), followed by piperacillin-tazobactam (26 cases). We note that 25 infections (16%) occurred during the first 6 months (early post-transplant period). Patients admitted during the early post-transplant period were more often on immunosuppressive treatment with prednisone (25/25 VS 106/133) (p = 0.01), mycophenolic acid (22/25 VS 86/133) (p = 0.03), presented for an urinary tract infection (10/25 VS 25/133) (p = 0.04) or a bacterial infection (17/25 VS 53/133) (p = 0.01). Patients with later infection had more comorbidities (57/83 VS 9/21) (p = 0.03), cancer (19/83 VS 0/21) (p = 0.04) or were on treatment with everolimus (46/133 VS 0/25) (p = 0.001). During 31 hospitalizations (20%), patients presented with a serious infection requiring intensive care (n = 26; 16%) or leading to death (n = 7; 4%). Bacteremia, pulmonary and cardiac complications were the main risk factors associated with poor outcome. CONCLUSION: Infections pose a significant challenge in the care of solid organ transplant patients, particularly those with comorbidities and intensive immunosuppression. This underscores the crucial importance of continuous surveillance and epidemiologic monitoring within this patient population.

Association between SARS-CoV-2 viral kinetics and clinical score evolution in hospitalized patients.

The role of antiviral treatment in coronavirus disease 2019 hospitalized patients is controversial. To address this question, we analyzed simultaneously nasopharyngeal viral load and the National Early Warning Score 2 (NEWS-2) using an effect compartment model to relate viral dynamics and the evolution of clinical severity. The model is applied to 664 hospitalized patients included in the DisCoVeRy trial (NCT04315948; EudraCT 2020-000936-23) randomly assigned to either standard of care (SoC) or SoC + remdesivir. Then we use the model to simulate the impact of antiviral treatments on the time to clinical improvement, defined by a NEWS-2 score lower than 3 (in patients with NEWS-2 <7 at hospitalization) or 5 (in patients with NEWS-2 ≥7 at hospitalization), distinguishing between patients with low or high viral load at hospitalization. The model can fit well the different observed patients trajectories, showing that clinical evolution is associated with viral dynamics, albeit with large interindividual variability. Remdesivir antiviral activity was 22% and 78% in patients with low or high viral loads, respectively, which is not sufficient to generate a meaningful effect on NEWS-2. However, simulations predicted that antiviral activity greater than 99% could reduce by 2 days the time to clinical improvement in patients with high viral load, irrespective of the NEWS-2 score at hospitalization, whereas no meaningful effect was predicted in patients with low viral loads. Our results demonstrate that time to clinical improvement is associated with time to viral clearance and that highly effective antiviral drugs could hasten clinical improvement in hospitalized patients with high viral loads.

Assessing complex interventions: a systematic review of outcomes used in randomised controlled trials on STI partner notification in high-income countries.

BACKGROUND: Partner notification interventions are complex and assessing their effectiveness is challenging. By reviewing the literature on the effectiveness of partner notification interventions, our aim was to evaluate the choice, collection, and interpretation of outcomes and their impact on study findings. METHODS: We conducted a systematic review of individual-level randomised controlled trials evaluating the effectiveness of partner notification interventions for bacterial STIs, HIV or sexually transmitted HCV in high-income countries since 2000. Partner notification interventions included assisted patient referral interventions and expedited treatment. The content analysis was carried out through a narrative review. RESULTS: In the 9 studies that met the inclusion criteria, 16 different outcomes were found. In most studies, one or two outcomes assessing partner notification practices were associated with an outcome reflecting STI circulation through index case reinfections. These outcomes assessed the main expected effects of partner notification interventions. However, partner notification is composed of a succession of actions between the intervention on the index case and the testing and/or treatment of the notified partners. Intermediate outcomes were missing so as to better understand levers and barriers throughout the process. Potential changes in participants' sexual behaviour after partner notification, e.g. condom use, were outcomes reported in only two studies assessing interventions including counselling. Most outcomes were collected through interviews, some weeks after the intervention, which might lead to desirability and attrition biases, respectively. Assessment of the effectiveness of partner notification interventions on partner testing/treatment was limited by the collection of data from index cases. Few data describing index cases and their partners were provided in the studies. Additional data on the number and type of exposed partners and the proportion of partners already aware of their infection before being notified would help to interpret the results. CONCLUSIONS: These insights would help to understand why and under what conditions the intervention is considered effective and therefore can be replicated or adapted to other populations and contexts.

Efficacy and safety of the novel capsid inhibitor lenacapavir to treat multidrug-resistant HIV: week 52 results of a phase 2/3 trial.

BACKGROUND: Lenacapavir, a first-in-class HIV-1 capsid inhibitor, is in development as a long-acting agent for treating and preventing HIV-1. We aimed to evaluate the efficacy and safety of lenacapavir with an optimised background regimen in adults living with multidrug-resistant HIV-1 up to 52 weeks. METHODS: This ongoing, international, phase 2/3 trial at 42 sites included adults living with multidrug-resistant HIV-1. In cohort 1, 36 participants were randomly assigned (2:1) to add oral lenacapavir (600 mg, days 1 and 2; 300 mg, day 8) or placebo to an existing failing regimen. At day 15, those on oral lenacapavir received subcutaneous lenacapavir 927 mg every 26 weeks; those on placebo started lenacapavir (2-week oral lead-in then subcutaneous). Cohort 1 started an optimised background regimen on day 15. In cohort 2 (non-randomised), 36 participants started an optimised background regimen concurrent with lenacapavir (oral to subcutaneous). Here we report the secondary endpoints of plasma HIV-1 RNA of less than 50 copies per mL or less than 200 copies per mL at week 52 (US Food and Drug Administration snapshot algorithm) in cohort 1 along with results for cohorts 1 and 2 combined. This trial is registered with ClinicalTrials.gov, NCT04150068, and clinicaltrialregister.eu, EudraCT 2019-003814-16 and is ongoing. FINDINGS: Of 72 participants, 46 (64%) had CD4 counts of less than 200 cells per µL and 38 (53%) had no more than one fully active antiretroviral drug at baseline. In cohort 1, 30 of 36 participants (83%, 95% CI 67-94) had less than 50 HIV-1 RNA copies per mL and 31 of 36 participants (86%, 71-95) had less than 200 HIV RNA copies per mL, at week 52. In all, nine participants (four in cohort 1, five in cohort 2) had emergent lenacapavir resistance; four resuppressed (HIV-1 RNA <50 copies per mL) while maintaining lenacapavir use. One participant discontinued study drug owing to injection site reaction. INTERPRETATION: In participants with multidrug-resistant HIV-1, subcutaneous lenacapavir in combination with an optimised background regimen resulted in a high rate of virological suppression up to 52 weeks. FUNDING: Gilead Sciences.