Importance The etiology of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, is unknown. However, neuroinflammation and complement activation may play a role in disease progression. Objective To determine the effects of zilucoplan, an inhibitor of complement C5, in individuals with ALS. Design, Setting, and Participants Zilucoplan was tested as regimen A of the HEALEY ALS Platform Trial, a phase 2 to 3 multicenter, randomized, double-blind, placebo-controlled perpetual platform clinical trial with sharing of trial infrastructure and placebo data across multiple regimens. Regimen A was conducted from August 17, 2020, to May 4, 2022. A total of 162 participants were randomized to receive zilucoplan (122 [75.3%]) or regimen-specific placebo (40 [24.7%]). An additional 124 concurrently randomized participants were randomized to receive placebo in other regimens. Interventions Eligible participants were randomized in a 3:1 ratio to receive zilucoplan or matching placebo within strata of edaravone and/or riluzole use for a planned duration of 24 weeks. Active drug (zilucoplan, 0.3 mg/kg) and placebo were provided for daily subcutaneous dosing. Main Outcomes and Measures The primary end point was change in disease severity from baseline through 24 weeks as measured by the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ALSFRS-R) total score and survival, analyzed using a bayesian shared-parameter model and reported as disease rate ratio (DRR; <1 indicating treatment benefit). The study included prespecified rules for early stopping for futility. Outcome analyses were performed in the full analysis set comparing the zilucoplan group with the total shared placebo group (n = 164). Results Among the 162 participants who were randomized (mean [SD] age, 59.6 [11.3]; 99 [61.1%] male), 115 (71.0%) completed the trial. The estimated DRR common to ALSFRS-R and survival was 1.08 (95% credible interval, 0.87-1.31; posterior probability of superiority, 0.24). The trial was stopped early for futility. No unexpected treatment-related risks were identified. Conclusions and Relevance In this randomized clinical trial of zilucoplan in ALS, treatment did not alter disease progression. The adaptive platform design of the HEALEY ALS Platform Trial made it possible to test a new investigational product with efficient use of time and resources. Trial Registration ClinicalTrials.gov Identifier: NCT04297683
Importance Bioenergetic failure has been proposed as a driver of amyotrophic lateral sclerosis (ALS). CNM-Au8 is a suspension of gold nanocrystals that catalyzes the conversion of nicotinamide adenine dinucleotide hydride into NAD + , resulting in an increase of cellular adenosine triphosphate production. Objective To determine the effects of CNM-Au8 on ALS disease progression. Design, Setting, and Participants CNM-Au8 was tested as a regimen of the HEALEY ALS Platform Trial, a phase 2/3, multicenter, randomized, double-blind platform trial. The study was conducted at 54 sites in the US from July 2020 to March 2022 (final follow-up, March 17, 2022). A total of 161 participants with ALS were randomized to receive CNM-Au8 (n = 120) or regimen-specific placebo (n = 41). Data from 123 concurrently randomized placebo participants in other regimens were combined for analyses. Interventions Eligible participants were randomized in a 3:3:2 ratio to receive CNM-Au8 60 mg daily (n = 61), CNM-Au8 30 mg daily (n = 59), or matching placebo (n = 41) for 24 weeks. Main Outcomes and Measures The primary efficacy outcome was change from baseline through week 24 in ALS disease severity measured by a bayesian shared parameter model of function (based on the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale) and survival, which provided an estimate of the rate of disease progression measured by the disease rate ratio (DRR), with a DRR of less than 1 indicating treatment benefit. Secondary end points included a Combined Assessment of Function and Survival using a joint-rank test, rate of decline in slow vital capacity (percent predicted), and survival free of permanent assisted ventilation. Results Among 161 participants who were randomized within the CNM-Au8 regimen (mean age, 58.4 years; 61 [37.9%] female), 145 (90%) completed the trial. In the primary analysis comparing the combined CNM-Au8 dosage groups vs the combined placebo groups, the primary end point (DRR, 0.97 [95% credible interval, 0.783-1.175]; posterior probability of DRR <1, 0.65) and the 3 secondary end points suggested no benefit or harm of CNM-Au8. In the active (n = 120) vs placebo (n = 163) groups, the most common adverse events were diarrhea (23 [19%] vs 12 [7%]), nausea (17 [14.2%] vs 14 [8.6%]), fatigue (12 [10.8%] vs 30 [18.4%]), and muscular weakness (24 [20%] vs 45 [27.6%]). Conclusions and Relevance No benefit of CNM-Au8 on ALS disease progression was observed at 24 weeks. Trial Registration ClinicalTrials.gov Identifiers: NCT04297683 , NCT04414345
P-1650. Clinical Outcomes among Patients Prescribed Suboptimal Antibiotic Therapy on Discharge to Nursing Homes
Abstract Background Little is known regarding outcomes for patients prescribed antibiotics on discharge from the hospital to nursing homes (NHs). We quantified the association between suboptimal antibiotic prescribing and clinical outcomes at discharge to NHs. Methods This was a multicenter, retrospective cohort study of adult (age >18 years) patients prescribed systemic antibiotics on discharge from 9 acute care hospitals in Oregon, Washington, and Wisconsin to a NH from 2016 – 2018. Study data were electronically extracted from hospital and NH electronic health records and supplemented with chart review. Suboptimal antibiotic therapy was determined by an infectious disease pharmacist or physician using clinical information (e.g., antibiotic regimen, indication, and culture results) available at discharge. Outcomes included emergency department (ED) visits, hospital readmissions, or Clostridioides difficile infection (CDI) within 30 days of hospital discharge. Comparison of outcomes between patients with suboptimal and non-suboptimal antibiotic therapy were tested by chi-squared tests. Results Among 280 included patients, mean (SD) age was 76.0 (11.5) years, 35.7% (n=100) were male, and median (IQR) inpatient length of stay was 6 (4-9) days. The most prevalent antibiotic indications were urinary tract infections (n =109, 38.9%), lung indications (n=60, 21.4%), and prophylaxis (n=29, 10.4%). Among 317 antibiotic prescriptions, the most frequently prescribed antibiotic classes were cephalosporins (n=83, 29.6%), fluoroquinolones (n=57, 20.4%), and beta-lactam/beta-lactamase-inhibitors (n=40, 14.3%). Fifty-eight patients (20.7%) were prescribed suboptimal antibiotic therapy on hospital discharge. There were no significant differences in the frequency of 30-day ED visits (14% vs 11%, p=0.76) or hospital readmission (19% vs 18%, p=0.94) between patients prescribed and not prescribed suboptimal antibiotics; however, suboptimal antibiotics were significantly associated with CDI within 30 days of discharge (10% vs 2%, p=0.01). Conclusion Suboptimal antibiotic prescribing on discharge to NHs was associated with increased risk of CDI within 30 days of discharge. This finding may inform interventions to improve antibiotic prescribing on discharge to NHs. Disclosures YoungYoon Ham, PharmD, Gilead: Honoraria Jon P. Furuno, PhD, Merck & Co., Inc: Grant/Research Support
Prospective Patient Preference Study for Bruton Tyrosine Kinase Inhibitor (BTKi) Treatment Attributes and Factors Affecting Patient Shared Decision-Making in Chronic Lymphocytic Leukemia (CLL) and Small Lymphocytic Lymphoma (SLL) in the United States (USA)
Introduction: The prognosis for CLL/SLL has improved with the advent of novel therapeutic classes, including BTKis. While comparative data for several BTKis have been published, there are limited data on patient preferences in BTKi treatment selection. Understanding and integrating patient perspective in the BTKi treatment selection process is crucial to shared decision-making and attaining optimal treatment outcomes. To understand patients' priorities for different treatment attributes that impact their treatment decisions, a comprehensive quantitative analysis of patient preferences on BTKi treatment attributes was conducted. Methods: A patient survey with a discrete-choice experiment (DCE) design was conducted from March to June 2024 among USA adults (≥18 years) with confirmed diagnosis of CLL/SLL, recruited through online patient panels, physician referrals, and support groups. BTKi treatment attributes were selected based on results of a targeted literature review and clinical inputs. Patients responded to DCE questions on attributes related to efficacy, safety (eg, impacts of diarrhea, headache, atrial fibrillation, and hypertension on quality of life [QoL]), formulation type, and dosing frequency. The impact of adverse events (AEs) on QoL was defined as the extent to which AEs caused interruptions in patients' ability to engage in their usual day-to-day activities. A conditional logistic regression model was used to calculate the relative importance of each attribute, as well as patient willingness to trade off specified BTKi treatment attributes. Results: A total of 200 patients with CLL/SLL completed the survey (median age: 61 years; 78% White; 55% female; 60% commercially insured; 82% suburban/urban residence). Less than half (43%) were diagnosed ≥5 years ago, and 61% received ≥3 lines of therapy. Almost all (89%) patients reported having experienced ≥1 AE from treatment previously, with the most common AEs being fatigue (76%), diarrhea (51%), headache (51%), and nausea and/or vomiting (51%). When considering the importance of efficacy measures, most patients prioritized CLL/SLL treatments that extended life expectancy (93%), followed by those that increased the likelihood of remission or cure (84%) and those that paused the progression of disease (67%). Patients preferred treatments with higher efficacy, less impact of AEs on QoL, and lower dosing frequency (P<.001). The top 3 treatment attributes with the highest relative importance to patients were impact of atrial fibrillation on QoL (24%), progression-free survival (PFS; 19%), and impact of headache on QoL (18%), followed by impact of diarrhea (14%) and hypertension (14%) on QoL, dosing frequency (9%), and formulation type (3%). On average, patients were willing to accept a reduction of 2.6, 1.9, 1.4, and 1.4 years of PFS to receive a treatment with less (none or mild vs significant) impact of atrial fibrillation, headache, diarrhea, and hypertension on QoL, respectively. Patients were willing to accept a reduction of 1.0 year of PFS to receive once-daily vs twice-daily treatment. Conclusions: Findings from this patient preference survey suggested that impact of atrial fibrillation on QoL, PFS, and impact of headache on QoL were the most important attributes of BTKi treatment for patients with CLL/SLL in the USA. Shared decision-making in CLL/SLL treatment selection should include an informed discussion about AEs, as besides efficacy comparisons, patients may prefer treatments with less impact of AEs on their QoL. Future prospective studies evaluating the effects of shared treatment decision-making on treatment adherence and outcomes are needed to better understand their impact on CLL/SLL patient care and inform clinical practice.
Caspase-1 Inhibition Ameliorates CAR T-Cell Apoptosis and Tumor Cell Pyroptosis to Enhance the Efficacy and Safety of CAR T-Cell Therapy
Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematological malignancies. However, CAR T-cell therapy still has low durable response rates and common associated toxicities such as cytokine release syndrome (CRS). We recently reported that sequential therapy with the CD19 monoclonal antibody tafasitamab and CD19-directed CAR T (CART19, 41BBζ costimulated) cells significantly ameliorated CAR T-cell apoptosis and tumor cell pyroptosis, improving CAR T safety and efficacy (PMID: 37879074). Building on these findings, we hypothesized that controlling massive initial CAR T-cell stimulation by diminishing extensive tumor cell pyroptosis is critical to improve CAR T safety and durability. To test this hypothesis, we evaluated several caspase (Casp) inhibitors, including Casp1, Casp3, Casp7, and Casp11, in combination with CAR T cells. We found that the Casp1 inhibitor VX765 did not inhibit CAR T antigen-specific cytotoxicity and thus focused on VX765 in subsequent assays. We first assessed CAR T proliferation upon stimulation with the CD19+ JeKo-1 mantle cell lymphoma cell line in the presence of VX765. CAR T with vehicle control showed greater proliferation at day 3, but CAR T with VX765 showed higher proliferation at day 5 (p=0.03, absolute CD3+ counts by flow cytometry). We then co-cultured CAR T and JeKo-1 for 24 hours and observed a significant reduction in apoptotic CAR T (Annexin V+ and 7-AAD- via flow cytometry) in VX765-treated conditions (p=0.05). Additionally, there was significantly reduced pyroptosis (Annexin V+ 7-AAD+) (p=0.02) but higher apoptosis (Annexin V+ 7-AAD-) in JeKo-1 in VX765-treated conditions (p=0.04). VX765-treated CAR T showed higher Bcl2 expression via flow cytometry (p=0.03). We also studied tumor cell pyroptosis by measuring the level of HMGB-1. CART19, JeKo-1, and VX765 or vehicle control were co-cultured for 24 hours, and the level of HMGB-1 was found to be significantly reduced in VX765-treated conditions, indicating reduced tumor pyroptosis (p=0.006). We then assessed the impact of Casp1 inhibition in our in vitro model of CAR T exhaustion. We stimulated CAR T with CD19+ JeKo-1 every other day for 2 weeks and then assessed CCR7 and CD45RA expression on CAR T. VX765-treated CAR T showed higher central memory (p=0.08) and naïve (p=0.02) and lower terminally differentiated effector memory phenotypes (p=0.03). We next studied the effect of Casp1 inhibition with VX765 in vivo. To recapitulate CAR T-cell toxicities, including CRS, we utilized an immunocompetent mouse model. First, we generated murine CART19 (mCART19, CD28ζ costimulated) cells. Recipient mice were then engrafted with luciferase+ murine CD19+ TBL12 cells, a murine lymphoma cell line. Mice were treated 12 days later with cyclophosphamide (300 mg/kg, ip) and 24 hours after mice were imaged and randomized to receive 1 x 107, 1) untransduced T cell control (UTD), 2) mCART19 + vehicle control, or 3) mCART19 + VX765 (25 mg/kg). VX765 was given immediately before the CART19 injection and on day 2 post-CAR T injection. Mice were serially monitored and weighed to assess CAR T-cell toxicity. Tumor burden was assessed via weekly bioluminescent imaging. Mice treated with vehicle control showed a significant reduction in weight compared to the UTD control (p=0.02), while mice treated with VX765 maintained their weight and remained active without signs of CRS, including motor weakness and hunched body. UTD mice reached humane endpoints within 3 weeks after T-cell injection. Three satellite mice from each group were euthanized and spleens were harvested. Flow cytometric analysis showed a significant reduction in apoptotic CAR T (p=) and pyroptotic tumor cells in mice treated with VX765 (p=0.03). Western blot showed lower cleaved GSDME and GSDMD in mice treated with VX765. VX765-treated mice demonstrated prolonged CAR T persistence with durable anti-tumor activity. In summary, Casp1 inhibition with VX765 significantly reduced CAR T apoptosis, improved memory phenotype, and increased delayed CAR T proliferation. VX765 also reduced tumor cell pyroptosis and CRS incidence without impacting CAR T anti-tumor activity in vivo. Given the favorable preclinical outcomes and existing clinical data on VX765, this approach holds substantial translational potential for enhancing the safety and efficacy of CAR T-cell therapy in patients with large B-cell lymphoma.
Distinct Functional Impacts of Cytokine Receptor Blockade on CART Cells
CD19-targeted chimeric antigen receptor T (CART19) cell therapy has shown outstanding clinical success. However, patients can develop CART-induced toxicities, including cytokine release syndrome (CRS) and neurotoxicity. Studies have found that activation of myeloid cells by granulocyte monocyte-colony stimulating factor (GM-CSF) can contribute to toxicity development. GM-CSF depletion leads to reduced myeloid activation, prevention of CART-induced toxicities, and improved CART efficacy. CART cells upregulate cytokine receptors upon activation, and our results indicate that CART19 cells significantly upregulate GMCSFR upon antigen-specific stimulation (<10% vs >30%, p<0.01). This led us to hypothesize that GMCSFR signaling contributes to CART cell activity. To understand the role of GM-CSFR upregulation on CART cell functions, we compared the impacts of neutralizing GM-CSF or blocking GM-CSF receptor alpha (GM-CSFRα) on CART19. First, 4-1BB-costimulated CART19 cells generated from healthy donors were stimulated with CD3/CD28 beads at a 1:3 ratio for 6 days. CART cells were maintained at 1 x 106/mL throughout the culture and supplemented with IgG isotype control, GM-CSF neutralizing antibody, or GM-CSFRα blockade at 10 μg/mL, 20 μg/mL, or 100 μg/mL. On day 6, cells were debeaded and rested for 2 days. Then, CART cells were cocultured with NALM6, a CD19+ acute lymphoblastic leukemia cell line, at a ratio of 1:1 for 3 days. The cocultures were supplemented with the same doses of antibodies listed above. Antigen-specific proliferation of CART cells was measured by flow cytometry. Our data suggested that CART19 proliferated is not impacted by GM-CSF neutralization but is inhibited by GM-CSFRα blockade (IgG isotype vs 10 μg/mL GM-CSFRα blockade, p<0.0001; IgG isotype vs 20 μg/mL GM-CSFRα blockade, p<0.0001; IgG isotype vs 100 μg/mL GM-CSFRα blockade, p=0.009). CART cells were assessed in a cytotoxicity assay with NALM6 luciferase+ cells as well, which did not show significant impacts from GM-CSF neutralization or GM-CSFRα blockade. To evaluate the impacts of GM-CSF neutralization and GM-CSFRα blockade in a mouse model, we engrafted NSG mice with 1 million NALM6 luciferase+ cells intravenously. Mice were then treated with 1.4 million CART19 plus 10 mg/kg IgG isotype control, GM-CSF neutralizing antibody, or GM-CSFRα blockade intraperitoneally. GM-CSFRα blockade drastically suppressed antitumor activities of CART (CART19+GM-CSFRα blockade vs CART19+IgG isotype control, p<0.0001; CART19+GM-CSFRα blockade vs CART19+GM-CSF neutralizing antibody, p<0.0001; CART19+ GM-CSFRα blockade vs untransduced T cell, n.s.). Serum cytokines were analyzed 2 days after CART treatment, showing that mice with GM-CSFRα blockade had significantly lower levels of human IFNγ (p=0.0189) and IL-2 (p=0.0121) compared to IgG isotype control group, while GM-CSF neutralization did not show significant impacts. Mice treated with CART plus IgG isotype control or GM-CSF neutralizing antibody showed prolonged survival compared to mice treated with GM-CSFRα blockade or untransduced T cells (p=0.0285). To unravel the mechanisms behind functional differences between GM-CSFRα blockade and GM-CSF neutralization, CART cells (n = 3 biological replicates) were cocultured with NALM6 at a 1:1 ratio supplemented with 10 μg/mL GM-CSF neutralizing antibody, GM-CSFRα blockade, or IgG isotype control overnight, followed by T cell isolation, bulk RNA isolation, and RNA sequencing (RNAseq) analysis. Our RNAseq data indicated significant upregulation (Log2FC>0.5, padj. <0.05) of T cell exhaustion- and dysfunction-associated genes (RGS16, PDCD1, CTLA4, NR4A3, CD101, LAG3) as well as negative regulators of T cell functions (G0S2, PIK3IP1, LGALS3) in the GM-CSFRα blockade group compared to GM-CSF neutralizing antibody or IgG isotype control groups. T cell activation-associated pathways were enriched in the GM-CSFRα blockade group. Overall, our data show that GM-CSFRα blockade impacts CART functions differently from GM-CSF neutralization. Specifically, GM-CSFRα blockade inhibits CART proliferation in vitro and antitumor activity in vivo. Interestingly, GM-CSFRα blockade leads to enrichment of T cell exhaustion- and dysfunction-associated genes in CART19, which is worth further investigation. These findings may be applicable to other cytokine receptors upregulated on activated CART cells.
Impact of frailty in hospitalized patients undergoing catheter ablation for atrial fibrillation
Abstract Background Catheter Ablation (CA) is an effective treatment for atrial fibrillation (AF). However, frail elderly patients have been understudied due to their exclusion from landmark trials. Objectives Our study aims to evaluate outcomes in this population. Methods The national readmission database (2016–2020) was queried, and frailty categories were defined based on hospital risk frailty scores ≦5 as low while >5 as intermediate/high frailty (IHF). We used multivariate regression and propensity‐matched analysis to compare outcomes in patients undergoing CA for atrial fibrillation based on frailty index. Results Among 55 936 CAs for AF, 33,248 patients had low frailty, while 22 688 had intermediate/high frailty (IHF). After propensity matching (N 12 448), IHF patients were found to have higher adverse events, including mortality (3% vs. 0.3%, p < .001), stroke (1.9% vs. 0.2%, p < .001), acute heart failure (53.8% vs. 42.2%, p < .001), AKI (42.5% vs. 6.8%, p < .001), pericardial complications (2.8 vs. 1.6%, p < .001), respiratory complications (27.8 vs. 7.2%, p < .001), major adverse cardiovascular events (21.2 vs. 9.4%, p < .001) and net adverse events (76.7 vs. 55%, p < .001). IHF patients had higher readmissions at 30 (15.5 vs. 12.6%, p < .001), 90 (31.9 vs. 25.1%, p < .001), and 180‐day (41 vs. 34.7%, p < .001) intervals. A higher median length of stay (LOS) (7 vs. 3 days, p < .001) and cost ($44 287 vs. $27 517, p < .001) at index admission and subsequent readmissions were also observed ( p < .001). Conclusion Intermediate/high frailty patients undergoing catheter ablation had worse clinical outcomes, higher healthcare burden, and readmission rates. LOS has decreased in both groups from 2016 to 2020; however, total cost has increased.
Vigorous Exercise in Patients With Congenital Long QT Syndrome: Results of the Prospective, Observational, Multinational LIVE-LQTS Study
BACKGROUND: Whether vigorous exercise increases risk of ventricular arrhythmias for individuals diagnosed and treated for congenital long QT syndrome (LQTS) remains unknown. METHODS: The National Institutes of Health–funded LIVE-LQTS study (Lifestyle and Exercise in the Long QT Syndrome) prospectively enrolled individuals 8 to 60 years of age with phenotypic and/or genotypic LQTS from 37 sites in 5 countries from May 2015 to February 2019. Participants (or parents) answered physical activity and clinical events surveys every 6 months for 3 years with follow-up completed in February 2022. Vigorous exercise was defined as ≥6 metabolic equivalents for >60 hours per year. A blinded Clinical Events Committee adjudicated the composite end point of sudden death, sudden cardiac arrest, ventricular arrhythmia treated by an implantable cardioverter defibrillator, and likely arrhythmic syncope. A National Death Index search ascertained vital status for those with incomplete follow-up. A noninferiority hypothesis (boundary of 1.5) between vigorous exercisers and others was tested with multivariable Cox regression analysis. RESULTS: Among the 1413 participants (13% <18 years of age, 35% 18–25 years of age, 67% female, 25% with implantable cardioverter defibrillators, 90% genotype positive, 49% with LQT1, 91% were treated with beta-blockers, left cardiac sympathetic denervation, and/or implantable cardioverter defibrillator), 52% participated in vigorous exercise (55% of these competitively). Thirty-seven individuals experienced the composite end point (including one sudden cardiac arrest and one sudden death in the nonvigorous group, one sudden cardiac arrest in the vigorous group) with overall event rates at 3 years of 2.6% in the vigorous and 2.7% in the nonvigorous exercise groups. The unadjusted hazard ratio for experience of events for the vigorous group compared with the nonvigorous group was 0.97 (90% CI, 0.57–1.67), with an adjusted hazard ratio of 1.17 (90% CI, 0.67–2.04). The upper 95% one-sided confidence level extended beyond the 1.5 boundary. Neither vigorous or nonvigorous exercise was found to be superior in any group or subgroup. CONCLUSIONS: Among individuals diagnosed with phenotypic and/or genotypic LQTS who were risk assessed and treated in experienced centers, LQTS-associated cardiac event rates were low and similar between those exercising vigorously and those not exercising vigorously. Consistent with the low event rate, CIs are wide, and noninferiority was not demonstrated. These data further inform shared decision-making discussions between patient and physician about exercise and competitive sports participation. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02549664.
A Glycemic Status Classification Model Using a Radiofrequency Noninvasive Blood Glucose Monitor
Despite significant efforts in the development of noninvasive blood glucose (BG) monitoring solutions, delivering an accurate, real-time BG measurement remains challenging. We sought to address this by using a novel radiofrequency (RF) glucose sensor to noninvasively classify glycemic status. The study included 31 participants aged 18–65 with prediabetes or type 2 diabetes and no other significant medical history. During control sessions and oral glucose tolerance test sessions, data were collected from both a RF sensor that rapidly scans thousands of frequencies and concurrently from a venous blood draw measured with an US Food and Drug Administration (FDA)-cleared glucose hospital meter system to create paired observations. We trained a time series forest machine learning model on 80% of the paired observations and reported results from applying the model to the remaining 20%. Our findings show that the model correctly classified glycemic status 93.37% of the time as high, normal, or low.
Non-invasive Blood Glucose Monitoring Using a Radiofrequency Sensor and a Machine Learning Model
Diabetes Mellitus (DM) affects over 530 million people globally and is a condition characterized by high blood glucose (BG) that can result in severe long-term health consequences if poorly managed. To mitigate the risks associated with DM, it is crucial to regulate BG levels through regular monitoring. Current methods of monitoring BG come with drawbacks in the form of pain and expense. With the rapid increase in prevalence of DM, there is an increasing need for economical, accurate, and non-invasive continuous measures of BG. Here we present a validation for a novel sensor that rapidly scans through a wide range of radio frequencies (RF) and uses machine learning (ML) techniques for the purpose of non-invasive BG measurement. After model training, the RF sensor and ML techniques employed in this study can predict BG at a level significantly better than chance, as shown below. Data were collected from 13 healthy participants over a series of tests lasting 2 – 3 hours. During each test, participants placed their forearm on an RF sensor that measured their BG levels using sweeps across the 500 MHz – 1500 MHz range at 0.1 MHz intervals. Participants ingested 37.5 grams of glucose solution to generate BG readings across normoglycemic and hyperglycemic ranges. Each sweep took approximately 22 seconds, including a one second pause between sweeps. Across 110 tests, we collected 3,311 BG observations. Concurrent measurements from a Continuous Glucose Monitor (CGM) were taken as reference. Data were divided using a 60-20-20 (training-validation-test) split and trained on a Light Gradient-Boosting Machine (lightGBM) model to predict BG values. A ‘blind’ evaluation of model performance was determined using the held-out test dataset. We predicted BG values in the held-out test dataset with a Mean Absolute Relative Difference (MARD) of 10.8% in the normoglycemic range and 15.9% in the hyperglycemic range (11.27% overall MARD). These results were significantly better than a chance model (two-sample t-test, p <0.01). In a Surveillance Error Grid analysis of model accuracy, 89.0% of predictions fell in Risk Level 0, 10.1% in Risk Level 1, and 0.9% in Risk Level 2. These results demonstrate that the novel RF sensor and ML techniques described can predict a reference BG value in the population under study. More research is underway to refine and expand these methods using a gold-standard blood glucose reference device and among a broader participant population with an expanded glucose range. DK and VS are consultants for and own stock in Know Labs. JA and KC are employed by and have stock options in Know Labs. CW and KP are consultants for Know Labs. NA. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.