CCR5 inhibition in critical COVID-19 patients decreases inflammatory cytokines, increases CD8 T-cells, and decreases SARS-CoV2 RNA in plasma by day 14

OBJECTIVE

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is now a global pandemic. Emerging results indicate a dysregulated immune response. Given the role of CCR5 in immune cell migration and inflammation, we investigated the impact of CCR5 blockade via the CCR5-specific antibody leronlimab on clinical, immunological, and virological parameters in severe COVID-19 patients.

METHODS

In March 2020, 10 terminally ill, critical COVID-19 patients received two doses of leronlimab via individual emergency use indication. We analyzed changes in clinical presentation, immune cell populations, inflammation, as well as SARS-CoV-2 plasma viremia before and 14 days after treatment.

RESULTS

Over the 14-day study period, six patients survived, two were extubated, and one discharged. We observed complete CCR5 receptor occupancy in all donors by day 7. Compared with the baseline, we observed a concomitant statistically significant reduction in plasma IL-6, restoration of the CD4/CD8 ratio, and resolution of SARS-CoV2 plasma viremia (pVL). Furthermore, the increase in the CD8 percentage was inversely correlated with the reduction in pVL (r = -0.77, p = 0.0013).

CONCLUSIONS

Our study design precludes clinical efficacy inferences but the results implicate CCR5 as a therapeutic target for COVID-19 and they form the basis for ongoing randomized clinical trials.

Disruption of the CCL5/RANTES-CCR5 Pathway Restores Immune Homeostasis and Reduces Plasma Viral Load in Critical COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is now pandemic with nearly three million cases reported to date. Although the majority of COVID-19 patients experience only mild or moderate symptoms, a subset will progress to severe disease with pneumonia and acute respiratory distress syndrome (ARDS) requiring mechanical ventilation. Emerging results indicate a dysregulated immune response characterized by runaway inflammation, including cytokine release syndrome (CRS), as the major driver of pathology in severe COVID-19. With no treatments currently approved for COVID-19, therapeutics to prevent or treat the excessive inflammation in severe disease caused by SARS-CoV-2 infection are urgently needed. Here, in 10 terminally-ill, critical COVID-19 patients we report profound elevation of plasma IL-6 and CCL5 (RANTES), decreased CD8+ T cell levels, and SARS-CoV-2 plasma viremia. Following compassionate care treatment with the CCR5 blocking antibody leronlimab, we observed complete CCR5 receptor occupancy on macrophage and T cells, rapid reduction of plasma IL-6, restoration of the CD4/CD8 ratio, and a significant decrease in SARS-CoV-2 plasma viremia. Consistent with reduction of plasma IL-6, single-cell RNA-sequencing revealed declines in transcriptomic myeloid cell clusters expressing IL-6 and interferon-related genes. These results demonstrate a novel approach to resolving unchecked inflammation, restoring immunologic deficiencies, and reducing SARS-CoV-2 plasma viral load via disruption of the CCL5-CCR5 axis, and support randomized clinical trials to assess clinical efficacy of leronlimab-mediated inhibition of CCR5 for COVID-19.

Disruption of CCR5 signaling to treat COVID-19-associated cytokine storm: Case series of four critically ill patients treated with leronlimab

Coronavirus disease 2019 (COVID-19) is associated with considerable morbidity and mortality. The number of confirmed cases of infection with SARS-CoV-2, the virus causing COVID-19 continues to escalate with over 70 million confirmed cases and over 1.6 million confirmed deaths. Severe-to-critical COVID-19 is associated with a dysregulated host immune response to the virus, which is thought to lead to pathogenic immune dysregulation and end-organ damage. Presently few effective treatment options are available to treat COVID-19. Leronlimab is a humanized IgG4, kappa monoclonal antibody that blocks C–C chemokine receptor type 5 (CCR5). It has been shown that in patients with severe COVID-19 treatment with leronlimab reduces elevated plasma IL-6 and chemokine ligand 5 (CCL5), and normalized CD4/CD8 ratios. We administered leronlimab to 4 critically ill COVID-19 patients in intensive care. All 4 of these patients improved clinically as measured by vasopressor support, and discontinuation of hemodialysis and mechanical ventilation. Following administration of leronlimab there was a statistically significant decrease in IL-6 observed in patient A (p=0.034) from day 0–7 and patient D (p=0.027) from day 0–14. This corresponds to restoration of the immune function as measured by CD4+/CD8+ T cell ratio. Although two of the patients went on to survive the other two subsequently died of surgical complications after an initial recovery from SARS-CoV-2 infection.

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Leronlimab is a monoclonal antibody in clinical trials to treat the cytokine storm.

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Critically ill patients received leronlimab through compassionate use and had remarkable recoveries measured objectively.

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The CCR5 receptor is important in recruiting inflammatory cells mainly T cells and macrophages.

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Leronlimab disrupted this signal and may have been responsible for restoration of the immune system, improved survival and decrease in IL-6.

PRO 140, a monoclonal antibody targeting CCR5, as a long-acting, single-agent maintenance therapy for HIV-1 infection

Background PRO 140 is a humanized monoclonal antibody targeting CCR5 with potent antiviral activity in patients with CCR5-tropic HIV-1 infection. In phase 2b studies, we evaluated the long-term efficacy, safety, and tolerability of PRO 140 monotherapy in maintaining viral suppression for over 24 months in patients who were stable on combination antiretroviral therapy on entry into the trials. Methods and Results Forty-one adult patients, infected exclusively with CCR5-tropic HIV-1 with viral loads <50 copies/mL, were switched from daily oral combination ART regimens to weekly PRO 140 monotherapy for 12 weeks. Participants who completed 12 weeks of treatment without experiencing virologic rebound were allowed to self-administer PRO 140 as a 350 mg subcutaneous injection weekly, for up to an additional 160 weeks. Participants were monitored bi-weekly for one year, and every four weeks thereafter for virologic rebound. PRO 140 provided virologic suppression in 23/41 (56.1%) participants for 12 weeks and was well tolerated. Ten (10) participants are currently ongoing, of which nine participants have completed more than two years of monotherapy treatment (47-129 weeks). Participants experiencing virologic rebound achieved full viral suppression upon re-initiation of oral combination ART regimen. Anti-PRO 140 antibodies were not detected in any patient, and no drug-related major adverse events or treatment discontinuations were reported. Conclusions PRO 140 has a potential to address an unmet need for a long-acting, single-agent, maintenance regimen for HIV infection in selected patients. Studies are underway to determine host and/or virologic factors that may predict treatment success on PRO 140 monotherapy. Moreover, it has sufficient potency for a prolonged period of monotherapy that it would be an excellent component of a multi long-acting drug combination.

Clinical Characteristics and Outcomes of Coronavirus Disease 2019 Patients Who Received Compassionate-Use Leronlimab

BACKGROUND

Leronlimab, a monoclonal antibody blocker of C-C chemokine receptor type 5 originally developed to treat human immunodeficiency virus infection, was administered as an open-label compassionate-use therapeutic for coronavirus disease 2019 (COVID-19).

METHODS

Twenty-three hospitalized severe/critical COVID-19 patients received 700 mg leronlimab subcutaneously, repeated after 7 days in 17 of 23 patients still hospitalized. Eighteen of 23 received other experimental treatments, including convalescent plasma, hydroxychloroquine, steroids, and/or tocilizumab. Five of 23 received leronlimab after blinded, placebo-controlled trials of remdesivir, sarilumab, selinexor, or tocilizumab. Outcomes and results were extracted from medical records.

RESULTS

Mean age was 69.5 ± 14.9 years; 20 had significant comorbidities. At baseline, 22 were receiving supplemental oxygen (3 high flow, 7 mechanical ventilation). Blood showed markedly elevated inflammatory markers (ferritin, D-dimer, C-reactive protein) and an elevated neutrophil-to-lymphocyte ratio. By day 30 after initial dosing, 17 were recovered, 2 were still hospitalized, and 4 had died. Of the 7 intubated at baseline, 4 were fully recovered off oxygen, 2 were still hospitalized, and 1 had died.

CONCLUSIONS

Leronlimab appeared safe and well tolerated. The high recovery rate suggested benefit, and those with lower inflammatory markers had better outcomes. Some, but not all, patients appeared to have dramatic clinical responses, indicating that unknown factors may determine responsiveness to leronlimab. Routine inflammatory and cell prognostic markers did not markedly change immediately after treatment, although interleukin-6 tended to fall. In some persons, C-reactive protein clearly dropped only after the second leronlimab dose, suggesting that a higher loading dose might be more effective. Future controlled trials will be informative.

Safety and efficacy of a novel silver-impregnated urinary catheter system for preventing catheter-associated bacteriuria: a pilot randomized clinical trial

BACKGROUND

The purpose of this study was to evaluate the safety of a novel silver-impregnated Foley catheter system designed to prevent catheter-associated bacteriuria and funguria, assess recruitment feasibility for a future pivotal trial, and preliminarily assess efficacy.

METHODS

This single-center, randomized controlled trial at a university hospital involved adult neurosurgical patients expected to have a urinary catheter for ≥24 hours. Subjects were randomized to a novel silver-impregnated (test) Foley catheter system or a control system. They were followed for 30 days (or until discharge) while catheterized and for up to 48 hours after catheter removal, with daily bacteriuria testing and assessment for symptoms of infection and catheter intolerance.

RESULTS

Ninety-five subjects were randomized (intention-to-treat [ITT] population). Of these, 61 subjects (64%) had a catheter for ≥24 hours without perioperative antibiotics beyond 24 hours (evaluable population). In the ITT population, 11 of 95 (12%) subjects had an asymptomatic bacteriuria (ABU) event. Compared with controls, test system recipients had a trend toward longer time to ABU in the ITT population (P = .08, log-rank test) and a longer time to ABU in the evaluable population (P = .03). All 6 ABU events caused by gram-negative bacilli occurred in the control group.

CONCLUSION

In this pilot randomized trial the test system was well tolerated and seemingly effective in preventing catheter-associated bacteriuria, especially with gram-negative bacilli. A pivotal study is warranted.

Antibody-based CCR5 blockade protects Macaques from mucosal SHIV transmission

In the absence of a prophylactic vaccine, the use of antiretroviral therapy (ART) as pre-exposure prophylaxis (PrEP) to prevent HIV acquisition by uninfected individuals is a promising approach to slowing the epidemic, but its efficacy is hampered by incomplete patient adherence and ART-resistant variants. Here, we report that competitive inhibition of HIV Env-CCR5 binding via the CCR5-specific antibody Leronlimab protects rhesus macaques against infection following repeated intrarectal challenges of CCR5-tropic SHIVSF162P3. Injection of Leronlimab weekly at 10 mg/kg provides significant but partial protection, while biweekly 50 mg/kg provides complete protection from SHIV acquisition. Tissue biopsies from protected macaques post challenge show complete CCR5 receptor occupancy and an absence of viral nucleic acids. After Leronlimab washout, protected macaques remain aviremic, and adoptive transfer of hematologic cells into naïve macaques does not transmit viral infection. These data identify CCR5 blockade with Leronlimab as a promising approach to HIV prophylaxis and support initiation of clinical trials.

Abstract CT233: Phase Ib/II study of leronlimab (PRO 140) combined with carboplatin in CCR5+ mTNBC patients

Introduction: Triple Negative Breast Cancer (TNBC) represents the most deadly form of invasive disease. It is associated with clinical and pathological features of highly proliferative and rapidly spreading cancer demonstrating higher incidence in younger women, particularly of African-American ethnicity and accounting for a disproportionately high percentage of early development of metastatic disease and breast-cancer-related death. While chemotherapy remains the main treatment option for both primary and metastatic TNBC (mTNBC) there is no optimized therapy for its management due to tumor heterogeneity, leaving the condition with an unmet medical need. Recent preclinical research demonstrated an important role for chemokine receptor type 5 (CCR5) in modulating cell migration and immune microenvironment suggesting a potential new therapeutic target in mTNBC [Jiao X et al, Can Res 2018;78:1657-71]. Leronlimab (PRO 140) is a humanized IgG4,к monoclonal antibody (mAb) to the C-C chemokine receptor type 5 (CCR5). Leronlimab has been administered and generally well tolerated in more than 750 healthy and HIV-1 infected individuals in Phase I/II/III studies. An ongoing Phase Ib/II study is being conducted to assess the safety and clinical outcomes of leronlimab combined with carboplatin in patients with untreated CCR5+ metastatic Triple Negative Breast Cancer (mTNBC). Methods: Eligible patients are required to have confirmed HER2 negative, ER &lt;1%, PR&lt;1% and demonstrate CCR5+ by immunohistochemistry assay (IHC) (&gt;10% of primary or metastatic cancer cells shows membranous staining and/or high predominance of CCR5+ tumor-infiltrating leukocytes (see representative IHC staining images below) Phase Ib of the CD07_TNBC study is a multicenter, single arm, dose escalation phase with 3 dose levels of leronlimab administered in combination with a fixed dose of carboplatin at AUC 5. The starting dose is 350 mg with escalation to 525 mg and 700 mg in the absence of dose-limiting toxicities. Leronlimab is administered as subcutaneous injection in the abdomen weekly and can be self-administered by subjects at home after proper training by a healthcare professional. Carboplatin is administered at AUC 5 every 3 weeks. The maximum tolerated dose (MTD) of leronlimab determined during the Phase Ib portion will be administered to 30 patients during the Phase II portion of the study. Correlative Data: Blood samples are collected at Day 1 of each treatment cycle (every 21 days) to assess changes in circulating tumor cells (CTCs) and cancer associated macrophage-like cells (CAMLs) after treatment and to perform correlative analysis with CCR5 expression. Conclusions: Leronlimab (PRO 140), a CCR5 antagonist mAb, in combination with carboplatin is currently enrolling newly diagnosed mTNBC. The preliminary analysis shows safety and tolerability of the combination and continue to enroll patients with initial promising clinical activity, potentially suggesting the future availability of a new effective agent in the management of this serious condition.

Citation Format: Massimo Cristofanilli, Milana Dolezal, Jay Lalezari, Hallgeir Rui, Bruce Patterson, Cha-Mei Tang, Daniel Adams, Qiang Zhang, Kazem Kazempour, Nader Pourhassan, Natalie Rabb, Kush Dhody. Phase Ib/II study of leronlimab (PRO 140) combined with carboplatin in CCR5+ mTNBC patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT233.

Suppression of human and simian immunodeficiency virus replication with the CCR5-specific antibody Leronlimab in two species

The CCR5-specific antibody Leronlimab is being investigated as a novel immunotherapy that can suppress HIV replication with minimal side effects. Here we studied the virological and immunological consequences of Leronlimab in chronically CCR5-tropic HIV-1 infected humans (n = 5) on suppressive antiretroviral therapy (ART) and in ART-naïve acutely CCR5-tropic SHIV infected rhesus macaques (n = 4). All five human participants transitioned from daily combination ART to self-administered weekly subcutaneous (SC) injections of 350 mg or 700 mg Leronlimab and to date all participants have sustained virologic suppression for over seven years. In all participants, Leronlimab fully occupied CCR5 receptors on peripheral blood CD4+ T cells and monocytes. In ART-naïve rhesus macaques acutely infected with CCR5-tropic SHIV, weekly SC injections of 50 mg/kg Leronlimab fully suppressed plasma viremia in half of the macaques. CCR5 receptor occupancy by Leronlimab occurred concomitant with rebound of CD4+ CCR5+ T-cells in peripheral blood, and full CCR5 receptor occupancy was found in multiple anatomical compartments. Our results demonstrate that weekly, self-administered Leronlimab was safe, well-tolerated, and efficacious for long-term virologic suppression and should be included in the arsenal of safe, easily administered, longer-acting antiretroviral treatments for people living with HIV-1. Trial Registration: ClinicalTrials.gov Identifiers: NCT02175680 and NCT02355184.