Optimal Combination Therapy Research Articles

Proof-of-concept for incorporating mechanistic insights from multi-omics analyses of polymyxin B in combination with chloramphenicol against Klebsiella pneumoniae.

Carbapenemase-resistant Klebsiella pneumoniae (KP) resistant to multiple antibiotic classes necessitates optimized combination therapy. Our objective is to build a workflow leveraging omics and bacterial count data to identify antibiotic mechanisms that can be used to design and optimize combination regimens. For pharmacodynamic (PD) analysis, previously published static time-kill studies (J Antimicrob Chemother 70, 2015, 2589) were used with polymyxin B (PMB) and chloramphenicol (CHL) mono and combination therapy against three KP clinical isolates over 24 h. A mechanism-based model (MBM) was developed using time-kill data in S-ADAPT describing PMB-CHL PD activity against each isolate. Previously published results of PMB (1mg/L continuous infusion) and CHL (Cmax : 8mg/L; bolus q6h) mono and combination regimens were evaluated using an in vitro one-compartment dynamic infection model against a KP clinical isolate (108 CFU/ml inoculum) over 24 h to obtain bacterial samples for multi-omics analyses. The differentially expressed genes and metabolites in these bacterial samples served as input to develop a partial least squares regression (PLSR) in R that links PD responses with the multi-omics responses via a multi-omics pathway analysis. PMB efficacy was increased when combined with CHL, and the MBM described the observed PD well for all strains. The PLSR consisted of 29 omics inputs and predicted MBM PD response (R2 =0.946). Our analysis found that CHL downregulated metabolites and genes pertinent to lipid A, hence limiting the emergence of PMB resistance. Our workflow linked insights from analysis of multi-omics data with MBM to identify biological mechanisms explaining observed PD activity in combination therapy.

Adjuvant immunotherapy in early-stage resectable non-small cell lung cancer: A new milestone.

Currently, chemotherapy is the standard adjuvant treatment for early-stage non-small cell lung cancer (NSCLC). However, adjuvant cisplatin-based chemotherapy after surgery has been shown to improve 5-year survival rates by only 4-5%. Immunotherapy using immune checkpoint inhibitors (ICIs) has revolutionized the treatment of advanced NSCLC, there is a growing interest in the role of immunotherapy in early-stage NSCLC. Here, we summarize the rationale for adjuvant immunotherapy, including the postoperative immunosuppressive environment and immunological effects of platinum chemotherapy. Many ongoing clinical trials and the related progress in adjuvant immunotherapy in early-stage resectable NSCLC are discussed. Furthermore, we highlight several unresolved challenges, including markers predictive of treatment benefit, the efficacy of treatment for some oncogene-addicted tumors, the optimal combination therapy, the duration of adjuvant immunotherapy, and optimal selection between neoadjuvant and adjuvant immunotherapy. Early findings in some clinical trials are promising, and updated overall survival results will be useful for validating the current role of adjuvant immunotherapy, particularly in the context of perioperative strategy.

The nature of changes in cell renewal and apoptosis of gingival epithelium in postmenopausal patients with chronic generalized periodontitis

Objective: to identify the nature of proliferation and apoptosis process disorders in the gingival epithelium in postmenopausal women with varying degrees of bone mineralization for early diagnosis and optimization of combination therapy. Materials and Methods. We examined 80 women aged 55–60 years with chronic generalized periodontitis (CGP) and reduced bone mineral density (BMD). All patients underwent a standard dental examination, including an index assessment of periodontal tissues. BMD was quantified via a densitometric analysis of the bone tissue condition. The investigation of periodontal epithelial cell renewal was performed using immunohistochemical studies. Results. We discovered that in postmenopausal patients with CGP and BMD disorders, there was a reduction in the proliferation of gingival epithelial cells with activation of their apoptosis (Iapt=0.73±0.03%, Iki-67=11.77±0.27%) vs. the patients with intact periodontium (Iapt 0.29±0.04%, Iki-67=9.88±0.09%), p=0.04. Conclusion. We discovered that CGP in postmenopausal women occurs with enlarged activity of apoptosis of gingival epithelial cells against the background of their reduced proliferation. The activity of inflammatory destructive processes in periodontal tissues is higher in patients with osteopenia vs. those without BMD impairment.

Advances in Innate Immunity to Overcome Immune Rejection during Xenotransplantation

Transplantation is an effective approach for treating end-stage organ failure. There has been a long-standing interest in xenotransplantation as a means of increasing the number of available organs. In the past decade, there has been tremendous progress in xenotransplantation accelerated by the development of rapid gene-editing tools and immunosuppressive therapy. Recently, the heart and kidney from pigs were transplanted into the recipients, which suggests that xenotransplantation has entered a new era. The genetic discrepancy and molecular incompatibility between pigs and primates results in barriers to xenotransplantation. An increasing body of evidence suggests that innate immune responses play an important role in all aspects of the xenogeneic rejection. Simultaneously, the role of important cellular components like macrophages, natural killer (NK) cells, and neutrophils, suggests that the innate immune response in the xenogeneic rejection should not be underestimated. Here, we summarize the current knowledge about the innate immune system in xenotransplantation and highlight the key issues for future investigations. A better understanding of the innate immune responses in xenotransplantation may help to control the xenograft rejection and design optimal combination therapies.

Preclinical Studies and Phase II Trial of Venetoclax in Combination with Chidamide and Azacitidine in Relapsed/Refractory Acute Myeloid Leukemia

Background: The treatment for relapsed and refractory acute myeloid leukemia (R/R AML) remains challenging and leukemia stem cells (LSCs) play a causal role in R/R AML. Recent progress in genomics and molecular biology has uncovered a spectrum of mutations in AML suggesting that translational research combined with targeted therapy for LSCs has greater guiding significance to improve outcome in R/R AML. Therefore, we used a high-throughput screening platform to identify a novel and effective therapeutic combination, which is venetoclax, chidamide, and azacitidine (VCA). Next, to assess the efficacy of VCA, we performed preclinical studies on LSCs-like cell lines and patient-derived xenograft (PDX) mouse model. In addition, a subsequent phase II study was conducted to test the safety and preliminary efficacy of this combination. Methods:Preclinical: We performed an automated drug screen to evaluate the drug sensitivity in CD34+CD38- KG-1α and Kasumi-1 cells simultaneously. Ultimately select the optimal combination therapy of venetoclax, chidamide, and azacitidine (VCA) by using a high-throughput platform. To validate the efficacy of the combination in vivo, we used primary CD34+ AML PDX model. Mice were treated with single, dual, or triple of venetoclax (VEN, 30 mg/kg, oral gavage), chidamide (CS055, 7.5 mg/kg, oral gavage), and azacitidine (5-AZA, 2 mg/kg, intraperitoneal injection) every 3 days for 12 days consecutively. Phase II: In a multi-center, single-arm, open-labeled phase II study, patients aged ≥18 years with R/R AML were treated with VEN at 200 mg orally daily for 14 days, CS055 at 30 mg orally twice per week for 14 days, and 5-AZA at 100 mg by continuous hypodermic injection (IH) daily for 7 days for up to two 28-day cycles. The primary objective was to assess the safety and efficacy of VCA. The primary efficacy measurement was overall response rate (ORR), which was the combined complete remission (CR), CR with incomplete hematologic recovery (CRi) and partial remission (PR). ResultsPreclinical: VCA exhibited synergistic effects on attenuating cell viability and inducing apoptosis in CD34+CD38- KG-1α and Kasumi-1 cells. Importantly, triple therapy intensively reduced leukemia burden and improved prognosis in a primary CD34+ AML derived PDX model without significant adverse effects versus single or double combination. Mechanistically, co-exposure to three agents led to the inhibition of anti-apoptotic BCL-2 family proteins (including BCL2, BCL-XL and MCL-1), associating with enhanced ubiquitination. Moreover, CS055-mediated HDAC inhibition increased F-box and WD repeat domain-containing protein 7 (FBW7) acetylation, thus resulting in FBW7 stabilization, which further enhanced the MCL-1 protein degradation. Phase II: As of July 30th, 2022, 29 patients were enrolled in the study. Patients had a median age of 51 years (range: 35-64). The median time on study was 31 (range: 4-not reached [NR]) days. 25 patients (86.2%) had confirmed responses. The ORR was 75% (12/16: 2 CR, 7 CRi and 3PR) with one complete and 88.9% (8/9: 5 CR, 2 CRi and 1 PR) with two completes. The most common non-hematologic adverse events (AE) were nausea (75%) and vomiting (25%), and no grade III or IV non-hematologic AE was observed. There was no tumor lysis syndrome (TLS) or treatment-discontinuation due to therapy. Conclusions: This novel combination strategy of VEN, CS055 and 5-AZA has shown synergy in AML LSCs-like cells and PDX model. The phase II data suggests that VCA as a chemo-free therapy exhibits promising efficacy and is safe and well-tolerated in patients with R/R AML.

Expert clinical framework report: Management of adverse events related to novel therapies for relapsed/refractory multiple myeloma (RRMM)

Multiple Myeloma (MM) is a malignancy of the plasma cells accumulating in the bone marrow. MM develops stepwise from the premalignant conditions, monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). The Canadian Cancer Society estimates that in 2022 4,000 Canadians will be diagnosed, and 1,650 will die from MM. Survival rates have improved over the years with the development of novel treatment strategies, including proteasome inhibitors (PI), immunomodulatory drugs (IMiDs), targeted antibody and cellular therapies, and a selective inhibitor of nuclear export (SINE), as well as with the use of combinations of drugs. Although a number of patients will have a durable response following high-dose chemotherapy and autologous stem cell transplant (ASCT), MM remains an incurable malignancy with the majority of patients relapsing and eventually developing refractory disease (RRMM). Collaborative environments, in which pharmacists work with hematologists/oncologists, nurse practitioners, and supportive care teams, have been shown to improve adherence to the treatment plan. Prescription of appropriate prophylaxis in combination with various treatment strategies may reduce the number and duration of treatment delays. Intensified clinical and pharmaceutical care, including medication management and structured patient counseling for patients on oral anticancer drugs, has been shown to reduce the number of medication errors and severe side effects while improving the patient’s treatment experience. Nurses play a vital role in the management of toxicities as they educate, support, and advocate for patients. This report discusses the management of adverse events (AEs) related to both established agents and novel therapies for the optimal management of patients with RRMM. Established and novel therapies are often used in combination, which presents the potential for overlapping toxicities. The optimal combination therapies including the sequencing of various regimens are yet to be determined. Basic research and clinical trials with investigational agents are ongoing in an effort to improve both the depth and duration of response in newly diagnosed patients and those with RRMM with the aim of finding the best treatment options for every patient.

A systematic review and network meta-analysis of first-line immune checkpoint inhibitor combination therapies in patients with advanced non-squamous non-small cell lung cancer.

Clinical evidence suggests that first-line immune checkpoint inhibitor (ICI) combination therapies can improve survival in patients with advanced non-squamous non-small cell lung cancer (nsq-NSCLC). However, the optimal strategy remains unknown without a systematic comparison of their long-term effects. We performed a systematic review and network meta-analysis by retrieving up-to-date literature from PubMed® (National Library of Medicine, Bethesda, MD, USA), Embase® (Elsevier, Amsterdam, Netherlands), MEDLINE® (National Library of Medicine), ClinicalTrials.gov (National Library of Medicine), and major international conference publications. Published studies and abstracts comparing first-line ICI combination therapies with other treatments for patients with advanced nsq-NSCLC were included. Restricted mean survival time (RMST) was measured over 12 months for progression-free survival (PFS) and 18 months for overall survival (OS), and the Royston-Parmar model was used to extrapolate and compare data for the long-term outcomes. We included a total of 11 trials involving 12 therapies and 6,130 patients. Pembrolizumab plus chemotherapy exhibited the best overall survival (OS) benefit at both 18 and 60 months [RMST = 2.95, 95% confidence interval (CI) 1.96 to 3.97; life-years gained over a 5-year period = 2.18 years]. Nivolumab plus bevacizumab plus chemotherapy was found to present the best progression-free survival (PFS) benefit at 12 months (RMST 3.02, 95% CI 2.11 to 3.91), whereas atezolizumab plus bevacizumab plus chemotherapy showed the best PFS benefit at 36 months (life-years gained over 3 years = 1.22 years). Subgroup analyses showed that among patients with programmed death-ligand 1 (PD-L1) expression ≥ 50%, atezolizumab plus chemotherapy and nivolumab plus ipilimumab resulted in superior OS benefits at 18 and 60 months, respectively. Among patients with PD-L1 expression< 1%, pembrolizumab plus chemotherapy was associated with OS benefits at both 18 and 60 months. Sintilimab plus chemotherapy was associated with relatively fewer grade ≥ 3 adverse events than other ICI combination therapies. Our results show that ICI combination therapies showed better survival benefits than chemotherapy. Pembrolizumab plus chemotherapy could provide the best OS benefits to patients with advanced nsq-NSCLC, whereas atezolizumab plus bevacizumab plus chemotherapy could bring the best PFS benefits. The optimal ICI combination therapy varies depending on PD-L1 expression level. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=325005, identifier CRD42022325005.

A quantitative systems pharmacology model for simulating OFF-Time in augmentation trials for Parkinson's disease: application to preladenant.

The clinical impact of therapeutic interventions in Parkinson's disease is often measured as a reduction in OFF-time when the beneficial effects of the standard-of-care L-DOPA formulations wanes off. We investigated the pharmacodynamic interactions of augmentation therapy to standard-of-care using a quantitative systems pharmacology (QSP) model of the basal ganglia motor circuit, essentially a computer model of neuronal firing in the different subregions with anatomically informed connectivity, cell-specific expression of 17 different G-protein coupled receptors and corresponding coupling to voltage-gated ion channel effector proteins based on experimentally observed intracellular signaling. The calculated beta/gamma (b/g) power spectrum of the local field potentials in the subthalamic nucleus was previously calibrated on the clinically relevant Unified Parkinson's Disease Rating Scale (UPDRS). When combining this QSP model with PK modeling of different formulations of L-DOPA, we calculated the b/g fluctuations over a 16h awake period and used a weighted distance from a specific threshold to determine the cumulative liability of OFF-Time. Prediction of OFF-time with clinical observations of different L-DOPA formulations showed a significant correlation. Simulations show that augmentation with the adenosine A2A antagonist preladenant reduces OFF-time with 6min for carbidopa/levodopa 950mg 5-times daily to 37min for 100mg L-DOPA - 3 or 5 times daily. Exploring delays between preladenant and L-DOPA intake did not improve the outcome. Hypothetical A2A antagonists with an ideal PK and pharmacology profile can achieve OFF-Time reductions ranging from 9.5min with DuoDopa to 55min with low dose L-DOPA formulations. Combination of the QSP model with PK modeling can predict the anticipated OFF-Time reduction of novel A2A antagonists with standard of care. With the large number of GPCR in the model, this combination can support both the design of clinical trials with new therapeutic agents and the optimization of combination therapy in clinical practice.

Current Molecular Combination Therapies Used for the Treatment of Breast Cancer.

Breast cancer is the second leading cause of death for women worldwide. While monotherapy (single agent) treatments have been used for many years, they are not always effective, and many patients relapse after initial treatment. Moreover, in some patients the response to therapy becomes weaker, or resistance to monotherapy develops over time. This is especially problematic for metastatic breast cancer or triple-negative breast cancer. Recently, combination therapies (in which two or more drugs are used to target two or more pathways) have emerged as promising new treatment options. Combination therapies are often more effective than monotherapies and demonstrate lower levels of toxicity during long-term treatment. In this review, we provide a comprehensive overview of current combination therapies, including molecular-targeted therapy, hormone therapy, immunotherapy, and chemotherapy. We also describe the molecular basis of breast cancer and the various treatment options for different breast cancer subtypes. While combination therapies are promising, we also discuss some of the challenges. Despite these challenges, the use of innovative combination therapy holds great promise compared with traditional monotherapies. In addition, the use of multidisciplinary technologies (such as nanotechnology and computer technology) has the potential to optimize combination therapies even further.

JS04.5.A Enhancing the activity of anti-CD47 antibody therapy with radiotherapy in preclinical models of medulloblastoma

Abstract Background Brain cancers are the most common solid cancer in children and the leading cause of cancer-related deaths in children. Medulloblastoma is the most common paediatric brain tumour. Treatment for medulloblastoma involves surgery, craniospinal irradiation (CSI) and chemotherapy. These therapies are extremely damaging to the developing brain and have not changed in decades, resulting in stagnation in the survival outcomes for children with medulloblastoma, and poor quality of life for children who survive their treatment. Immunotherapy has become a focus of novel treatment development. While there are multiple clinical trials aiming to increase immune recognition of medulloblastoma, none have been successful to date. Anti-CD47 is an immune-modulating therapeutic antibody which blocks the anti-phagocytic signal, CD47, expressed by brain cancer cells. Anti-CD47 has shown promising preliminary efficacy in brain cancer models. Material and Methods Using a small animal radiotherapy platform, we have developed a preclinical CSI protocol which mimics clinical radiotherapy. Using an orthotopic xenograft model of medulloblastoma, mice were treated with either anti-CD47 antibody therapy, CSI, or the combination of both anti-CD47 and CSI. Results CSI was found to deplete adaptive immune cells in the brain, while myeloid cells remained the dominant populations. Anti-CD47 antibody therapy was ineffective as a single agent against a patient derived xenograft model of Group 3 medulloblastoma, and CSI as a monotherapy resulted in temporary tumour regression. We found that the combination of anti-CD47 with CSI resulted in marked and persistent tumour regression. Conclusion This preclinical work has shown promising efficacy of anti-CD47 in combination with CSI, which we are currently testing in additional models. Our work is currently employing a range of techniques such as high dimensional flow cytometry and single cell sequencing to elucidate the mechanisms by which radiotherapy enhances the anti-tumour activity of myeloid cells. This work will enable the rational design and translation of optimal combination therapies for medulloblastoma clinical trials.

HER2 in Non-Small Cell Lung Cancer: A Review of Emerging Therapies.

Simple SummaryThere are growing data on targeting HER2 alterations, which include gene mutations, gene amplifications, and protein overexpression, for non-small cell lung cancer (NSCLC). Currently, there are limited targeted therapies approved for NSCLC patients with HER2 alterations, and this remains an unmet clinical need. There has been an influx of research on antibody–drug conjugates, monoclonal antibodies, and tyrosine kinase inhibitors. This review discusses the diagnostic challenges of HER2 alterations in NSCLC and summarizes recent progress in HER2 targeted drugs for both clinicians and researchers treating this patient population.Human epidermal growth factor receptor 2 (HER2), a member of the ERBB family of tyrosine kinase receptors, has emerged as a therapeutic target of interest for non-small cell lung cancer (NSCLC) in recent years. Activating HER2 alterations in NSCLC include gene mutations, gene amplifications, and protein overexpression. In particular, the HER2 exon 20 mutation is now a well clinically validated biomarker. Currently, there are limited targeted therapies approved for NSCLC patients with HER2 alterations. This remains an unmet clinical need, as HER2 alterations are present in 7–27% of de novo NSCLC and may serve as a resistance mechanism in up to 10% of EGFR mutated NSCLC. There has been an influx of research on antibody–drug conjugates (ADCs), monoclonal antibodies, and tyrosine kinase inhibitors (TKIs) with mixed results. The most promising therapies are ADCs (trastuzumab-deruxtecan) and novel TKIs targeting exon 20 mutations (poziotinib, mobocertinib and pyrotinib); both have resulted in meaningful anti-tumor efficacy in HER2 mutated NSCLC. Future studies on HER2 targeted therapy will need to define the specific HER2 alteration to better select patients who will benefit, particularly for HER2 amplification and overexpression. Given the variety of HER2 targeted drugs, sequencing of these agents and optimizing combination therapies will depend on more mature efficacy data from clinical trials and toxicity profiles. This review highlights the challenges of diagnosing HER2 alterations, summarizes recent progress in novel HER2-targeted agents, and projects next steps in advancing treatment for the thousands of patients with HER2 altered NSCLC.

Patterns of Presentation of Drug-Resistant Tuberculosis in Nigeria: A Retrospective File Review

Background: An understanding of the patterns of drug-resistant tuberculosis (DR-TB) is needed to develop the best diagnostic tools and decide on optimal treatment combination therapies for the management of DR-TB in Nigeria. Objective: We aimed to investigate patterns of DR-TB for the five first-line anti-TB drugs over a period of seven years (2010–2016) and the associated clinical and socio-demographic factors. Methods: A retrospective study recruited 2555 DR-TB patients between 2010 and 2016 across the six geopolitical treatment zones in Nigeria. We determined DR-TB patterns based on standard case definition and their association with demographic and clinical information. Data were analyzed using Statistical Package for Social Sciences (SPSS) software. Independent predictors of DR-TB patterns/types were determined using bivariate and multivariate analyses with a statistical significance of p &lt; 0.05 and a 95% confidence interval. Results: The majority of the participants were males, 66.93% (1710), 31–40 years old, 35.19% (899), previously treated, 77.10% (1909), had received at least two treatments, 411 (49.94%) and were multi-drug resistant, 61.41% (1165). The Southwest zone had the highest number of DR-TB cases, 36.92%. We found an upward trend in the prevalence of DR-TB from 2010 to 2016. Participants who had received one previous treatment showed statistically significant higher rifampicin resistance (59.68%), those with two previous treatments reported a statistically significant higher polydrug resistance (78.57%), and those with three or more previous treatments had a statistically significant higher multidrug resistance (19.83%) (χ2 = 36.39; p = 0.001). Mono-drug resistance and rifampicin resistance were statistically significantly higher in the southwest zone (29.48% and 34.12% respectively), polydrug resistance in the northcentral (20.69%) and south-south zones (20.69%), and multidrug resistance in the southwest (30.03%) and northcentral zones (19.18%) (χ2 = 98.26; p = 0.001). Conclusions: We present patterns of DR-TB across the six geopolitical zones in Nigeria. Clinicians should weigh in on these patterns while deciding on the best first-line drug combinations to optimize treatment outcomes for DR-TB patients. A national scale-up plan for DST services should focus on patients with previous multiple exposures to anti-TB treatments and on those in the Northeastern zone of the country.

Optimizing combination therapy in a murine model of HER2+ breast cancer

Human epidermal growth factor receptor 2 positive (HER2+) breast cancer is frequently treated with drugs that target the HER2 receptor, such as trastuzumab, in combination with chemotherapy, such as doxorubicin. However, an open problem in treatment design is to determine the therapeutic regimen that optimally combines these two treatments to yield optimal tumor control. Working with data quantifying temporal changes in tumor volume due to different trastuzumab and doxorubicin treatment protocols in a murine model of human HER2+ breast cancer, we propose a complete framework for model development, calibration, selection, and treatment optimization to find the optimal treatment protocol. Through different assumptions for the drug–tumor interactions, we propose ten different models to characterize the dynamic relationship between tumor volume and drug availability, as well as the drug–drug interaction. Using a Bayesian framework, each of these models are calibrated to the dataset and the model with the highest Bayesian information criterion weight is selected to represent the biological system. The selected model captures the inhibition of trastuzumab due to pre-treatment with doxorubicin, as well as the increase in doxorubicin efficacy due to pre-treatment with trastuzumab. We then apply optimal control theory (OCT) to this model to identify two optimal treatment protocols. In the first optimized protocol, we fix the maximum dosage for doxorubicin and trastuzumab to be the same as the maximum dose delivered experimentally, while trying to minimize tumor burden. Within this constraint, optimal control theory indicates the optimal regimen is to first deliver two doses of trastuzumab on days 35 and 36, followed by two doses of doxorubicin on days 37 and 38. This protocol predicts an additional 45% reduction in tumor burden compared to that achieved with the experimentally delivered regimen. In the second optimized protocol we fix the tumor control to be the same as that obtained experimentally, and attempt to reduce the doxorubicin dose. Within this constraint, the optimal regimen is the same as the first optimized protocol but uses only 43% of the doxorubicin dose used experimentally. This protocol predicts tumor control equivalent to that achieved experimentally. These results strongly suggest the utility of mathematical modeling and optimal control theory for identifying therapeutic regimens maximizing efficacy and minimizing toxicity.

Polymyxin B in Combination with Glycerol Monolaurate Exerts Synergistic Killing against Gram-Negative Pathogens.

The rapid emergence and spread of multidrug-resistant (MDR) bacterial pathogens pose a serious danger to worldwide human health, and resistance to last-resort drugs, such as polymyxins, is being increasingly detected in MDR Gram-negative pathogens. There is an urgent need to find and optimize combination therapies as an alternative therapeutic strategy, with a dry pipeline in novel antibiotic research and development. We found a monoester formed from the combination of lauric acid and glycerol, glycerol monolaurate (GML), possessing prominent antibacterial and anti-inflammatory activity. However, it is still unclear whether GML in combination could increase antimicrobial activity. Here, we reported that polymyxin B (PMNB) combined with GML exhibited a synergistic antimicrobial impact on Gram-negative strains in vitro, including clinical MDR isolates. This synergistic antimicrobial activity correlated with the destruction of bacterial cell structures, eradication of preformed biofilms, and increased reactive oxygen species (ROS) accumulation. We also showed that PMNB synergized with GML effectively eliminated pathogens from bacterial pneumonia caused by Klebsiella pneumoniae to rescue mice. Our research demonstrated that the PMNB and GML combination induced synergistic antimicrobial activity for Gram-negative pathogens in vitro and in vivo. These findings are of great importance for treating bacterial infections and managing the spread of infectious diseases.

Design of an optimal combination therapy with broadly neutralizing antibodies to suppress HIV-1.

Infusion of broadly neutralizing antibodies (bNAbs) has shown promise as an alternative to anti-retroviral therapy against HIV. A key challenge is to suppress viral escape, which is more effectively achieved with a combination of bNAbs. Here, we propose a computational approach to predict the efficacy of a bNAb therapy based on the population genetics of HIV escape, which we parametrize using high-throughput HIV sequence data from bNAb-naive patients. By quantifying the mutational target size and the fitness cost of HIV-1 escape from bNAbs, we predict the distribution of rebound times in three clinical trials. We show that a cocktail of three bNAbs is necessary to effectively suppress viral escape, and predict the optimal composition of such bNAb cocktail. Our results offer a rational therapy design for HIV, and show how genetic data can be used to predict treatment outcomes and design new approaches to pathogenic control.

The IDentif.AI-x pandemic readiness platform: Rapid prioritization of optimized COVID-19 combination therapy regimens

IDentif.AI-x, a clinically actionable artificial intelligence platform, was used to rapidly pinpoint and prioritize optimal combination therapies against COVID-19 by pairing a prospective, experimental validation of multi-drug efficacy on a SARS-CoV-2 live virus and Vero E6 assay with a quadratic optimization workflow. A starting pool of 12 candidate drugs developed in collaboration with a community of infectious disease clinicians was first narrowed down to a six-drug pool and then interrogated in 50 combination regimens at three dosing levels per drug, representing 729 possible combinations. IDentif.AI-x revealed EIDD-1931 to be a strong candidate upon which multiple drug combinations can be derived, and pinpointed a number of clinically actionable drug interactions, which were further reconfirmed in SARS-CoV-2 variants B.1.351 (Beta) and B.1.617.2 (Delta). IDentif.AI-x prioritized promising drug combinations for clinical translation and can be immediately adjusted and re-executed with a new pool of promising therapies in an actionable path towards rapidly optimizing combination therapy following pandemic emergence.

The addition of oral iron improves chemotherapy-induced anemia in patients receiving erythropoiesis-stimulating agents.

Although many studies have shown that supplementation with iron and erythropoiesis-stimulating agents (ESA) is frequently used for managing chemotherapy-induced anemia (CIA), optimal combination therapy using these agents together to ameliorate anemia is not well characterized. To assess the effects of ESA combined with oral or intravenous (IV) iron on relieving CIA, PubMed, Cochrane Library, Embase and China National Knowledge Infrastructure (CNKI) were searched for articles. Data collected in the articles were meta-analyzed using RevMan 5.3 software with a random-effects model. Our comprehensive search yielded 1666 potentially relevant trials. A total of 41 trials randomizing 4200 patients with CIA fulfilled inclusion criteria, including 34 Chinese articles and 7 English articles. Meta-analysis showed that treatment with both ESA and iron more effectively improved CIA relative to iron supplementation alone, with increased hemoglobin, hematocrit, red blood cell count and hematopoietic response rate. Subgroup analyses revealed iron administration, both oral and IV iron, improved anemia in ESA-treated cancer patients with CIA. Our analysis demonstrates that iron supplementation combined with ESA more effectively ameliorates CIA relative to iron supplementation alone, without regard to whether IV or oral iron was used. Together, our findings may contribute to the clinical treatment of CIA using iron therapy with or without ESA.

Abstract 2732: A mathematical model for optimization of combination therapy involving targeted radionuclide and CAR-T cell therapy

Abstract Background: Immunotherapy with chimeric antigen receptor - T (CAR-T) cells and targeted radionuclide therapy (TRT) are two highly promising therapies in cancer treatment. Often, these therapies show limited efficacy in complete eradication of cancer cells making the combination of these two therapies an attractive cancer treatment option. The complications involved in dosing and scheduling of these therapies make mathematical modeling an appropriate method for analyzing and predicting disease response to these therapies. Here we propose a mathematical model evaluating disease response to the combination of these two therapies and explore the optimization of their dosing and scheduling. Methods: An ordinary differential equation-based formalism is proposed for simulation of tumor response to CAR-T cell therapy as well as TRT. CAR-T cell dose and injected radioactivity was input to the model. Among others, key model parameters included tumor proliferation rate, tumor cell and CAR-T cell radiosensitivity, CAR-T cell killing rate, CAR-T cell decay rate indicating persistence. Preclinical experiments involving CS1- CAR-T cell therapy and 225Ac-DOTA-Daratumumab TRT in a multiple myeloma mice model were used to parameterize the model. Sensitivity study of the model parameters using overall survival (OS) and progression-free survival (PFS) as evaluation metrics, was performed to elucidate the parameters with highest impact. Results: OS and PFS were 97 and 55 days when CAR-T cell therapy was given prior to TRT as compared to OS of 43 days for untreated control mice. Sensitivity study of model parameters showed that tumor proliferation has the highest impact on survival metrics. For a ±50% change in tumor proliferation rate, OS changed by -41%/+111% and PFS changed by -62%/+147%. Similar changes in TRT injected activity and CAR-T cell dose changed OS by ± 15% and ±21% respectively. Accordingly, PFS changed by roughly ±32% and ±45% respectively. A variation of the interval between the therapies showed that faster growing tumors required a shorter interval between the two therapies. The sequence of therapies was also changed and TRT prior to CAR-T cell therapy demonstrated shorter PFS (43 days) due to the adverse effects of radiation on CAR-T cells. Conclusion: For a fixed dose of TRT and CAR-T cells, tumor proliferation rate was found to be the prime factor impacting therapy interval. The presented work shows the key parameters required for planning and optimizing preclinical experiments and clinical trials. Using disease, CAR-T cell and radionuclide-specific parameters as shown in this work as well as incorporating immune stimulating effects of radiation would make it an extremely potent tool for optimizing combination therapies. Citation Format: Vikram Adhikarla, Dennis Awuah, Alexander B. Brummer, Enrico Caserta, Amrita Krishnan, Flavia Pichiorri, Megan M. Minnix, John E. Shively, Jeffrey Y.C. Wong, Xiuli Wang, Russell C. Rockne. A mathematical model for optimization of combination therapy involving targeted radionuclide and CAR-T cell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2732.

The Treatment of Painful Diabetic Neuropathy.

Painful diabetic peripheral neuropathy (painful-DPN) is a highly prevalent and disabling condition, affecting up to one-third of patients with diabetes. This condition can have a profound impact resulting in a poor quality of life, disruption of employment, impaired sleep, and poor mental health with an excess of depression and anxiety. The management of painful-DPN poses a great challenge. Unfortunately, currently there are no Food and Drug Administration (USA) approved disease-modifying treatments for diabetic peripheral neuropathy (DPN) as trials of putative pathogenetic treatments have failed at phase 3 clinical trial stage. Therefore, the focus of managing painful- DPN other than improving glycaemic control and cardiovascular risk factor modification is treating symptoms. The recommended treatments based on expert international consensus for painful- DPN have remained essentially unchanged for the last decade. Both the serotonin re-uptake inhibitor (SNRI) duloxetine and α2δ ligand pregabalin have the most robust evidence for treating painful-DPN. The weak opioids (e.g. tapentadol and tramadol, both of which have an SNRI effect), tricyclic antidepressants such as amitriptyline and α2δ ligand gabapentin are also widely recommended and prescribed agents. Opioids (except tramadol and tapentadol), should be prescribed with caution in view of the lack of definitive data surrounding efficacy, concerns surrounding addiction and adverse events. Recently, emerging therapies have gained local licenses, including the α2δ ligand mirogabalin (Japan) and the high dose 8% capsaicin patch (FDA and Europe). The management of refractory painful-DPN is difficult; specialist pain services may offer off-label therapies (e.g. botulinum toxin, intravenous lidocaine and spinal cord stimulation), although there is limited clinical trial evidence supporting their use. Additionally, despite combination therapy being commonly used clinically, there is little evidence supporting this practise. There is a need for further clinical trials to assess novel therapeutic agents, optimal combination therapy and existing agents to determine which are the most effective for the treatment of painful-DPN. This article reviews the evidence for the treatment of painful-DPN, including emerging treatment strategies such as novel compounds and stratification of patients according to individual characteristics (e.g. pain phenotype, neuroimaging and genotype) to improve treatment responses.

Tislelizumab, a PD-1 inhibitor for relapsed/refractory mature T/NK-cell neoplasms: Results from a phase 2 study.

7552 Background: Effective treatment choices for patients (pts) with relapsed/refractory (R/R) mature T/NK-cell neoplasms after failure of standard therapies are limited. Tislelizumab (TIS), a humanized anti-PD-1 mAb, demonstrated outstanding efficacy and favorable safety in pts with R/R classical Hodgkin lymphoma or solid tumors. We present safety and efficacy of the phase 2 study of TIS in pts with R/R mature T/NK-cell neoplasms. Methods: Pts were enrolled into 3 cohorts stratified by the type of T/NK-cell neoplasm to receive TIS 200 mg intravenously every 3 weeks until disease progression or intolerable toxicity. Eligible pts had ≥1 prior systemic therapy, disease progression during/after most recent therapy completion or refractory disease, ECOG ≤2, and life expectancy ≥6 mo. Primary endpoint was investigator-assessed overall response rate (ORR). Secondary endpoints included duration of response (DoR), complete response (CR) rate, progression-free survival (PFS), overall survival (OS) in cohorts 1 and 2, and safety. Results: 77 pts were treated. Cohort 1: R/R extranodal NK/T-cell lymphoma (n = 22); cohort 2: R/R mature T-cell neoplasms (n = 44; 21 peripheral T-cell lymphoma not otherwise specified; 11 angioimmunoblastic T-cell lymphoma; 12 anaplastic large cell lymphoma); cohort 3: R/R cutaneous T-cell lymphomas (CTCL; stage ≥1B; n = 11; 8 mycosis fungoides and 3 Sézary syndrome). Of all pts, 76.6% had advanced-stage disease, 51.9% had refractory disease, and 49.4% had ≥3 prior systemic regimens. Median treatment cycles for cohorts 1, 2, and 3 were 5 (range, 1-37), 4.5 (range, 1-38), and 17 (range, 3-25), respectively. Cohort 3 had promising efficacy (median follow-up [FU] 16.6 mo): ORR 45.5%; CR 9.1%; median DoR 11.3 mo (95% CI: 2.76-11.30); median PFS 16.8 mo; median OS not reached (NR). Modest efficacy was reported in cohort 1 (median FU 8.4 mo): ORR 31.8%; CR 18.2%; median DoR NR (95% CI: 2.66-not estimable [NE]); median PFS 2.7 mo; median OS 8.8 mo and also in cohort 2 (median FU 9.3 mo): ORR 20.5%; CR 9.1%; median DoR 8.2 mo (95% CI: 2.50-NE); median PFS 2.7 mo; median OS 13.3 mo. Most frequent adverse events (AEs) were pyrexia (32.5%), anemia (18.2%), arthralgia (18.2%), and diarrhea (15.6%); most frequent grade ≥3 AEs were anemia (7.8%), pneumonia (6.5%), and neutropenia (5.2%). Any grade immune-mediated AEs occurred in 22 (28.6%) pts, most frequently hypothyroidism (10.4%), hyperglycemia (5.2%), and rash (5.2%); and grade ≥3 in 4 (5.2%) pts (blood creatine phosphokinase increased, hepatitis, hypothyroidism, rash, and urticaria [1 pt each]). No treatment-related AEs led to death. Conclusions: TIS was well tolerated, achieving modest efficacy in R/R mature T/NK-cell neoplasms, with some long-lasting remissions particularly in CTCL. Further studies are warranted to determine the biologic features associated with response and explore optimal combination therapies. Clinical trial information: NCT03493451.