Neutralizing Antibody Sample Testing and Report Harmonization

Immunogenicity testing and characterization is an important part of understanding the immune response to administration of a protein therapeutic. Neutralizing antibody (NAb) assays are used to characterize a positive anti-drug antibody (ADA) response. Harmonization of reporting of NAb assay performance and results enables efficient communication and expedient review by industry and health authorities. Herein, a cross-industry group of NAb assay experts have harmonized NAb assay reporting recommendations and provided a bioanalytical report (BAR) submission editable template developed to facilitate agency filings. This document addresses key bioanalytical reporting gaps and provides a report structure for documenting clinical NAb assay performance and results. This publication focuses on the content and presentation of the NAb sample analysis report including essential elements such as the method, critical reagents and equipment, data analysis, study samples, and results. The interpretation of immunogenicity data, including the evaluation of the impact of NAb on safety, exposure, and efficacy, is out of scope of this publication.

16th GCC Closed Forum: ICH M10 implementation; NGS, qPCR/dPCR, flow cytometry validation; tissue biomarkers; IS response; immunogenicity harmonization; bioanalytical industry status

The 16th GCC Closed Forum was held in Orlando, FL, USA, on 23 June 2023. Representatives from international bioanalytical Contract Research Organizations were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at the meeting included: IS response, flow cytometry, changes to the bioanalytical industry, NGS assays, biomarker assay for tissues, dPCR validation, immunogenicity harmonization and ICH M10 implementation. Conclusions and consensus from discussions of these topics are included in this article.

Recommendations for Method Development and Validation of qPCR and dPCR Assays in Support of Cell and Gene Therapy Drug Development

The emerging use of qPCR and dPCR in regulated bioanalysis and absence of regulatory guidance on assay validations for these platforms has resulted in discussions on lack of harmonization on assay design and appropriate acceptance criteria for these assays. Both qPCR and dPCR are extensively used to answer bioanalytical questions for novel modalities such as cell and gene therapies. Following cross-industry conversations on the lack of information and guidelines for these assays, an American Association of Pharmaceutical Scientists working group was formed to address these gaps by bringing together 37 industry experts from 24 organizations to discuss best practices to gain a better understanding in the industry and facilitate filings to health authorities. Herein, this team provides considerations on assay design, development, and validation testing for PCR assays that are used in cell and gene therapies including (1) biodistribution; (2) transgene expression; (3) viral shedding; (4) and persistence or cellular kinetics of cell therapies.

Validation of Anti-Adeno Associated Virus Serotype rh10 (AAVrh.10) Total and Neutralizing Antibody Immunogenicity Assays

Immunogenicity assessment of Adeno-Associated Virus (AAV) vectors is a critical part of gene therapy drug development. Whether the assays are used for inclusion/exclusion criteria or to monitor the safety and efficacy of the gene therapy, they are critical bioanalytical assessments. While total anti-AAV assays are perceived as easier to develop and implement than neutralizing anti-AAV assays, the gene therapy field is still nascent, and it is not yet clear which of the assays should be implemented at what stage of drug development. Recently AAVrh.10 has gained interest for use in gene therapies targeting cardiac, neurological, and other diseases due to its enhanced transduction efficiency. There is limited information on anti-AAVrh.10 antibodies and their clinical impact; thus, the information presented herein documents the validation of both a total antibody assay (TAb) and a neutralizing antibody (NAb) assay for anti-AAVrh.10 antibodies. In this manuscript, the validation was performed in accordance with the 2019 FDA immunogenicity guidance with additional evaluations to comply with CLIA where applicable. The AAVrh.10 TAb and NAb assays were compared in terms of sensitivity, drug tolerance, and precision, along with a concordance analysis using the same individual serum samples. This comparison gave insight into the utility of each format as a screening assay for inclusion into clinical studies.

Utilization of a technology-assisted workflow to prepare controlled substance oral syringes

PURPOSE

Utilization of technology-assisted workflow (TAWF) systems has gained popularity in the sterile compounding setting. This study was designed to evaluate whether safety and efficiency could be seen when preparing oral controlled substance doses gravimetrically vs volumetrically.

METHODS

This 2-phase observational study combined manual data collection with automated logs generated by a single TAWF. During phase I, oral controlled substance solutions were prepared volumetrically. In phase II, the same subset of medications was to be prepared gravimetrically via the same TAWF. Findings from phases I and II were compared against each another to determine safety, efficiency, and documentation differences between the volumetric and gravimetric workflows.

RESULTS

Thirteen different medications were evaluated during phase I (1,495 preparations) and phase II (1,781 preparations) of this study. Mean compounding time (min:sec) increased in phase II when compared to phase I (1:49 vs 1:28; P < 0.01), with the deviation detection rate also increasing (7.9% vs 4.7%; P < 0.01). Despite a target in phase II of utilizing gravimetric analysis for more than 80% of preparations, only 45.5% (811 preparations) were prepared with this workflow, as adoption challenges and dose size limitations prevented compliance. Doses that were prepared gravimetrically had a mean accuracy rate of 100.6% (the mean achieved dose was 0.6% higher than the mean prescribed dose) and a rejection rate of 0.99% (compared to the phase I rejection rate of 1.07%; P = 0.67).

CONCLUSION

The gravimetric workflow provided accuracy and additional safety checks when compared to the volumetric alternative, all while providing users with greater access to data. Health systems should consider staffing, product sourcing, patient populations, and medication safety when determining the balance between volumetric and gravimetric workflows.

Neutralizing Antibody Validation Testing and Reporting Harmonization

Evolving immunogenicity assay performance expectations and a lack of harmonized neutralizing antibody validation testing and reporting tools have resulted in significant time spent by health authorities and sponsors on resolving filing queries. A team of experts within the American Association of Pharmaceutical Scientists' Therapeutic Product Immunogenicity Community across industry and the Food and Drug Administration addressed challenges unique to cell-based and non-cell-based neutralizing antibody assays. Harmonization of validation expectations and data reporting will facilitate filings to health authorities and are described in this manuscript. This team provides validation testing and reporting strategies and tools for the following assessments: (1) format selection; (2) cut point; (3) assay acceptance criteria; (4) control precision; (5) sensitivity including positive control selection and performance tracking; (6) negative control selection; (7) selectivity/specificity including matrix interference, hemolysis, lipemia, bilirubin, concomitant medications, and structurally similar analytes; (8) drug tolerance; (9) target tolerance; (10) sample stability; and (11) assay robustness.

Bioanalytical Assay Strategies and Considerations for Measuring Cellular Kinetics

A vast evolution of drug modalities has occurred over the last several decades. Novel modalities such as cell and gene therapies have proven to be efficacious for numerous clinical indications-primarily in rare disease and immune oncology. Because of this success, drug developers are heavily investing in these novel modalities. Given the complexity of these therapeutics, a variety of bioanalytical techniques are employed to fully characterize the pharmacokinetics of these therapies in clinical studies. Industry trends indicate that quantitative PCR (qPCR) and multiparameter flow cytometry are both valuable in determining the pharmacokinetics, i.e. cellular kinetics, of cell therapies. This manuscript will evaluate the pros and cons of both techniques and highlight regulatory guidance on assays for measuring cellular kinetics. Moreover, common considerations when developing these assays will be addressed.

Anti-drug Antibody Sample Testing and Reporting Harmonization

A clear scientific and operational need exists for harmonized bioanalytical immunogenicity study reporting to facilitate communication of immunogenicity findings and expedient review by industry and health authorities. To address these key bioanalytical reporting gaps and provide a report structure for documenting immunogenicity results, this cross-industry group was formed to establish harmonized recommendations and a develop a submission template to facilitate agency filings. Provided here are recommendations for reporting clinical anti-drug antibody (ADA) assay results using ligand-binding assay technologies. This publication describes the essential bioanalytical report (BAR) elements such as the method, critical reagents and equipment, study samples, results, and data analysis, and provides a template for a suggested structure for the ADA BAR. This publication focuses on the content and presentation of the bioanalytical ADA sample analysis report. The interpretation of immunogenicity data, including the evaluation of the impact of ADA on safety, exposure, and efficacy, is out of scope of this publication.

Natriuretic Peptide Levels and Clinical Outcomes among Patients Hospitalized with COVID-19 Infection

Purpose

There is increasing evidence of adverse cardiovascular morbidity associated with SARS-CoV-2 (COVID-19). Pro-B-type natriuretic peptide (proBNP) is a biomarker of myocardial stress associated with outcomes in various respiratory and cardiac diseases. We hypothesized that proBNP level would be associated with mortality and clinical outcomes in hospitalized COVID-19 patients.

Methods

We performed a retrospective analysis of hospitalized COVID-19 patients (n=1232) using adjusted logistic and linear regression to assess the association of admission proBNP (analyzed by both categorical cutoff >125 pg/mL and continuous log transformed proBNP) with clinical outcomes. Covariates included age, sex, race, body mass index (BMI), hypertension, coronary artery disease (CAD), diabetes, smoking history, and chronic kidney disease stage (Model 1), with Troponin I added in Model 2. We performed survival analysis by a multivariate Cox proportional hazard model, incorporating log transformed proBNP. We additionally treated BMI, a strong potential confounder of both proBNP levels and COVID-19 outcomes, as an ordinal variable ordered across tertiles.

Results

Patients were mean age 62.9±17.6, 53.8% male, and 35.9% Black. Preadmission comorbidities were hypertension (57.1%), diabetes (31.6%), CAD (9.0%) and heart failure (HF, 10.6%). In Model 1 and 2, higher proBNP level was significantly associated with death, new HF, length of stay, ICU duration and need for ventilation among hospitalized COVID-19 patients. This significance persisted after ordinal compression of BMI across tertiles. The adjusted hazard ratio of death for log[proBNP] was 1.56 (95% CI: 1.23-1.97; P<0.0001).

Conclusion

Using a relatively large and racially diverse hospitalized COVID-19 patient cohort, we find that proBNP is associated with adverse clinical outcomes, including mortality and new HF in COVID-19. Further prospective investigation is warranted on the utility of proBNP for clinical prognostication in COVID-19.

AAPS Perspective on the EURL Recommendation on the use of Non-Animal-Derived Antibodies

In May 2020, the EU Reference Laboratory for alternatives to animal testing (EURL ECVAM) published a recommendation report entitled "Recommendation on nonanimal-derived antibodies". In this report, the EURL ECVAM specifically states: "Therefore, taking into consideration the ESAC Opinion on the scientific validity of replacements for animal-derived antibodies, EURL ECVAM recommends that animals should no longer be used for the development and production of antibodies for research, regulatory, diagnostic and therapeutic applications. The provisions of Directive 2010/63/EU should be respected, and EU countries should no longer authorise the development and production of antibodies through animal immunisation, where robust, legitimate scientific justification is lacking." (1). Here, we are providing the American Association of Pharmaceutical Scientists (AAPS) opinion on the EURL ECVAM recommendation report. In brief, there has been a clear and strong progress in reduction of animal use in the drug discovery and development process, including significant reduction of animal use in production of antibody reagents. Yet, it is proposed that more data need to be generated, shared and discussed within the scientific community before a decision to implement the change to non-animal derived antibodies is made.

4313Evolocumab rapidly reverses impaired coronary endothelial function in six weeks in people living with HIV and in patients with dyslipidemia

Background/Introduction

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is well recognized for its importance in cholesterol metabolism. Elevated levels are associated with increased cardiovascular risk and inhibition with PCSK9 antibodies lowers cardiovascular events in patients with known coronary disease. PCSK9 levels are also elevated in people living with HIV (PLWH), and we previously reported that increased PCSK9 in PLWH is associated with impaired coronary endothelial function (CEF), a major driver for the development, progression, and clinical manifestations of coronary artery disease.

Purpose

Here we investigate the hypothesis that PCSK9 inhibition improves impaired CEF in PLWH and in patients with dyslipidemia (DL).

Methods

Cine 3T MRI was used to noninvasively measure CEF, assessed as the change in coronary cross-sectional area (CSA) from rest to isometric handgrip exercise (IHE), a known endothelial-dependent vasodilator. Eight HIV+ subjects on stable highly active antiretroviral therapy and with undetectable HIV RNA (mean age 53±9 yrs, LDLC 98±18 mg/dL, 38% on statins) and ten patients with dyslipidemia (DL) without HIV receiving evolocumab for clinical reasons (mean age 56±10 yrs, LDLC 130±28 mg/dL, 50% on statins) underwent MRI studies before and six weeks following the initiation of evolocumab 420 mg. MRI readers were blinded to group and timepoint. MRI data are presented as mean±SD for % change rest vs IHE.

Results

Prior to evolucumab, resting CSA in the two groups did not differ and IHE did not induce normal coronary vasodilation in either group; mean stress-induced CSA changes were −2.1±6.4% in HIV (p=0.27) and −0.6±4.1% in DL (p=0.46). Notably, CEF significantly improved following six weeks of evolocumab with IHE-induced CSA changes of 7.6±5.7% (p=0.006) and 5.0±3.6% (p=0.002) in the HIV and DL groups, respectively. The %-LDLC reduction with evolocumab was profound and comparable in the HIV and DL groups, 73±5% and 60±6% (p=0.19 HIV vs. DL). There was no significant correlation between the extents of LDLC reduction and of CEF improvement in either of these modest sized groups.

Conclusion

PCSK9 inhibition with evolocumab significantly improves abnormal coronary endothelial function after only six weeks in HIV+ people with normal LDLC and in HIV- people with DL. To our knowledge, these data represent the earliest (6 weeks) evidence for improvement in human coronary artery health by PCSK9 inhibition.

Acknowledgement/Funding

Amgen provided the PCSK9 monoclonal antibody (evolocumab) for this study.

Abstract P4-16-09: Effect of simvastatin on cardiac strain in breast cancer patients receiving anthracycline therapy

Background: Cardiac toxicity (CT) is a rare late effect of anthracycline therapy for breast cancer (BC). Statins may attenuate the CT of anthracyclines. Myocardial strain can detect subclinical CT before ejection fraction (EF) declines. Global longitudinal strain (GLS) ≥-19% and relative change (RelΔ) in GLS≥11% predict future decline in EF. We conducted a pilot study to evaluate the effect of simvastatin on GLS in BC patients receiving anthracyclines. Methods: We enrolled women with stage I-III BC planning doxorubicin/cyclophosphamide (AC) x 4. Women with heart disease or taking a statin were excluded. Participants were randomized 1:1 to simvastatin 40 mg daily x 24 weeks (wk) + AC or to AC alone. We performed echo with strain 5 times: baseline (BL), pre-AC#2, 1-3 wk after AC#4, 24 wk after AC #1 and 52 wk after AC#1. The primary endpoint was the mean absolute change (|Δ|) in GLS from BL to 1-3 wk after AC#4. Secondary endpoints included RelΔ in GLS, feasibility and safety. We used two-sample t-tests to compare mean changes in GLS and Fisher's exact test to compare dichotomized GLS values. The study closed early due to loss of staff. Results: Of 31 patients, 15 (48%) received simvastatin+AC. Mean age was 46 years; 71% pre-menopausal, 61% white and 32% black. There were no significant differences in BL cardiovascular risk factors between the arms. After AC, 3 HER2+ patients received trastuzumab. There were no grade 3-4 AEs with simvastatin. Common grade 1-2 AEs included myalgia (20%), elevated AST (27%) and elevated ALT (53%). One patient in the AC arm died from heart failure with low EF 2 months after having a normal echo 1-3 wk after AC#4. The rate of missing echos was 14%. Of 133 completed echos, 124 (93%) were evaluable for GLS. Mean GLS was &lt;-19% at all times in the simvastatin+AC arm. Mean GLS was &lt;-19% at BL and pre-AC#2 in the AC arm, but ≥-19% at post-AC times in the AC arm. Mean EF was &gt;60% at all times in both arms. Among 27 patients evaluable for the primary endpoint, there was no significant difference in mean |Δ| in GLS from BL to 1-3 wk after AC#4 between the arms (Simvastatin+AC: 0.42%; AC: 1.11%, p=0.57). In addition, there were no differences in the mean|Δ| in GLS from BL to any other time between the arms (all p&gt;0.1). The proportion of patients with GLS&lt;-19% was higher in the simvastatin+AC arm than in the AC arm pre-AC#2 (73% vs 44%), 1-3 wk after AC#4 (67% vs 38%), 24 wk after AC #1 (53% vs 25%) and 52 wk after AC#1 (53% vs 25%) (all p&gt;0.05). The proportion of patients with RelΔ in GLS≥11% from BL was lower in the simvastatin+AC arm than in the AC arm pre-AC#2 (13% vs 19%), 1-3 wk after AC#4 (20% vs 44%) and 24 wk after AC#1(27% vs 31%) (all p&gt;0.05). Conclusion: Simvastatin did not result in a statistically significant difference in the mean |Δ| in GLS from BL to 1-3 wk after AC#4. However, the study was underpowered due to small sample size and there was a suggestion of reduced CT with simvastatin. Co-administration of simvastatin and AC was safe and serial echocardiographic strain monitoring was feasible. Further studies are needed to evaluate the cardioprotective effect of statins on strain in BC patients receiving anthracyclines.

Citation Format: Smith KL, Griffin JM, Tsai H-L, Leathers M, Hays A, Lu D-Y, Zhang Z, Rosner GL, Russell SD, Connolly RM, Jelovac D, Visvanathan K, Wolff AC, Stearns V, Abraham T. Effect of simvastatin on cardiac strain in breast cancer patients receiving anthracycline therapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-16-09.

Improving Antimicrobial Use by Implementing the CDC Antimicrobial Stewardship Core Elements Across a Diverse Healthcare System

Background

With increasing national focus on reducing inappropriate antimicrobial use, state and national regulatory mandates require hospitals to develop robust antimicrobial stewardship programs (ASP).

Methods

BJC HealthCare is a 13 hospital healthcare system serving the St. Louis, mid-Missouri, and Southern Illinois region and includes adult and pediatric academic medical centers, as well as community and critical access hospitals. In 2015, BJC system leaders engaged relevant clinical and executive stakeholders at each hospital to champion formation of a multidisciplinary system ASP Council. A comprehensive gap analysis was performed to assess current stewardship resources and activities. BJC system clinical leads facilitated the development of hospital specific leadership support statements, identification of hospital pharmacy and medical leaders, and all mandated educational components. To facilitate tracking, reporting and improvement activities, a robust antimicrobial use data dashboard was created. Each hospital has a dedicated ASP team that is supported by the system clinical leads. Hospital learnings are shared at monthly system ASP meetings allowing for broad dissemination.

Results

By leveraging system resources, all 13 BJC HealthCare hospitals met all Joint Commission requirements by January 2017. BJC’s model of ASP allows for the development of broad-based stewardship activities including development of education modules for patients and providers, and clinical decision support tools while allowing individual hospitals to implement activities based on local needs and resource availability. Local hospital teams have developed treatment guidelines, targeted antibiotic pharmacy review, “handshake” stewardship models, and allergy testing protocols. Central support of local hospital ASP has resulted in a 7.6% system decrease in tracked antimicrobial use, including a 16.5% reduction in quinolone usage. Additionally, the C. difficilestandardized infection ratio decreased from 1.08 to 0.622 since program initiation.

Conclusion

Despite significant differences in hospital resources, a system-supported ASP model focused on implementing the CDC core elements can result in significant reductions in antimicrobial use.

Disclosures

J. Newland, Merck: Grant Investigator, Research grant; Allergan: Grant Investigator, Research grant

Cysteine scanning mutagenesis of transmembrane domain 10 in organic anion transporting polypeptide 1B1

Organic anion transporting polypeptide (OATP) 1B1 is an important drug transporter expressed in human hepatocytes. Previous studies have indicated that transmembrane (TM) domain 2, 6, 8, 9, and in particular 10 might be part of the substrate binding site/translocation pathway. To explore which amino acids in TM10 are important for substrate transport, we mutated 34 amino acids individually to cysteines, expressed them in HEK293 cells, and determined their surface expression. Transport activity of the two model substrates estrone-3-sulfate and estradiol-17β-glucuronide as well as of the drug substrate valsartan for selected mutants was measured. Except for F534C and F537C, all mutants were expressed at the plasma membrane of HEK293 cells. Mutants Q541C and A549C did not transport estradiol-17β-glucuronide and showed negligible estrone-3-sulfate transport. However, A549C showed normal valsartan transport. Pretreatment with the anionic and cell impermeable sodium (2-sulfonatoethyl)methanethiosulfonate (MTSES) affected the transport of each substrate differently. Pretreatment of L545C abolished estrone-3-sulfate uptake almost completely, while it stimulated estradiol-17β-glucuronide uptake. Further analyses revealed that mutant L545C in the absence of MTSES showed biphasic kinetics for estrone-3-sulfate that was converted to monophasic kinetics with a decreased apparent affinity, explaining the previously seen inhibition. In contrast, the apparent affinity for estradiol-17β-glucuronide was not changed by MTSES treatment, but the V_max value was increased about 4-fold, explaining the previously seen stimulation. Maleimide labeling of L545C was affected by preincubation with estrone-3-sulfate but not with estradiol-17β-glucuronide. These results strongly suggest that L545C is part of the estrone-3-sulfate binding site/translocation pathway but is not directly involved in binding/translocation of estradiol-17β-glucuronide.

Transport by OATP1B1 and OATP1B3 enhances the cytotoxicity of epigallocatechin 3-O-gallate and several quercetin derivatives

Organic anion transporting polypeptides (OATPs) 1B1 and 1B3 are transporters that are expressed selectively in human hepatocytes under normal conditions. OATP1B3 is also expressed in certain cancers. Flavonoids such as green tea catechins and quercetin glycosides have been shown to modulate the function of some OATPs. In the present study, the extent to which six substituted quercetin derivatives (1-6) affected the function of OATP1B1 and OATP1B3 was investigated. Uptake of the radiolabeled model substrates estradiol 17β-glucuronide, estrone 3-sulfate, and dehydroepiandrosterone sulfate (DHEAS) was determined in the absence and presence of compounds 1-6 using Chinese hamster ovary (CHO) cells stably expressing either OATP1B1 or OATP1B3. Several of compounds 1-6 inhibited OATP-mediated uptake of all three model substrates, suggesting that they could also be potential substrates. Compound 6 stimulated OATP1B3-mediated estradiol 17β-glucuronide uptake by increasing the apparent affinity of OATP1B3 for its substrate. Cytotoxicity assays demonstrated that epigallocatechin 3-O-gallate (EGCG) and most of compounds 1-6 killed preferentially OATP-expressing CHO cells. EGCG, 1, and 3 were the most potent cytotoxic compounds, with EGCG and 3 selectively killing OATP1B3-expressing cells. Given that OATP1B3 is expressed in several cancers, EGCG and some of the quercetin derivatives studied might be promising lead compounds for the development of novel anticancer drugs.

Organic anion transporting polypeptides expressed in pancreatic cancer may serve as potential diagnostic markers and therapeutic targets for early stage adenocarcinomas

PURPOSE

Organic Anion Transporting Polypeptides (OATPs) are expressed in various epithelial tissues in the body. Because they can be expressed in cancers and because they can transport anticancer drugs, OATPs could be potential targets for cancer therapy. Therefore we examined their expression in human pancreatic ductal adenocarcinomas.

METHODS

Expression of all 11 human OATPs was measured at the mRNA level and OATPs with highest expression were characterized at the protein level.

RESULTS

Transcripts of SLCO1B3, SLCO2A1, SLCO3A1 and SLCO4A1 were detected in all the tested pancreatic tissues. OATP1B3, OATP2A1, OATP3A1 and OATP4A1 protein expression was confirmed in these tissues and expression of all four transporters increased in pancreatic adenocarcinoma compared to normal pancreas. OATP1B3 expression was highest in pancreatic hyperplasia and stage one adenocarcinomas compared to stage two and three adenocarcinomas.

CONCLUSION

OATP1B3, OATP2A1, OATP3A1 and OATP4A1 are up-regulated in pancreatic adenocarcinoma and could potentially be used to target anticancer drugs to pancreatic cancer. Additionally, because expression of OATP1B3 is highest in pancreatitis and stage one adenocarcinoma, which leads to pancreatic cancer, OATP1B3 is a potential marker to diagnose patients with early stage pancreatic adenocarcinomas.

A 160-femtosecond optical image processor based on a conjugated polymer

Degenerate ground-state conjugated polymers exhibit large third-order nonlinear optical susceptibilities, including substantial two-photon absorption. With the use of a machine architecture suited to these material properties, ultrafast optical processors are possible. A four-wave mixing optical correlator was built with an air-stable, processable, degenerate ground-state conjugated polymer, poly(1,6-heptadiester). The continuously updatable processor correlates two 5000-pixel images in less than 160 femtoseconds, achieving peak processing rates of 3 x 10(16) operations per second.