Evaluation of a novel 177Lu-labelled therapeutic Affibody molecule with a deimmunized ABD domain and improved biodistribution profile.

PURPOSE: Fusion of Affibody molecules with an albumin-binding domain (ABD) provides targeting agents, which are suitable for radionuclide therapy. To facilitate clinical translation, the low immunogenic potential of such constructs with targeting properties conserved is required. METHODS: The HER2-targeting Affibody molecule ZHER2:2891 was fused with a deimmunized ABD variant and DOTA was conjugated to a unique C-terminal cysteine. The novel construct, PEP49989, was labelled with 177Lu. Affinity, specificity, and in vivo targeting properties of [177Lu]Lu-PEP49989 were characterised. Experimental therapy in mice with human HER2-expressing xenografts was evaluated. RESULTS: The maximum molar activity of 52 GBq/µmol [177Lu]Lu-PEP49989 was obtained. [177Lu]Lu-PEP49989 bound specifically to HER2-expressing cells in vitro and in vivo. The HER2 binding affinity of [177Lu]Lu-PEP49989 was similar to the affinity of [177Lu]Lu-ABY-027 containing the parental ABD035 variant. The renal uptake of [177Lu]Lu-PEP49989 was 1.4-fold higher, but hepatic and splenic uptake was 1.7-2-fold lower than the uptake of [177Lu]Lu-ABY-027. The median survival of xenograft-bearing mice treated with 21 MBq [177Lu]Lu-PEP49989 (> 90 days) was significantly longer than the survival of mice treated with vehicle (38 days) or trastuzumab (45 days). Treatment using a combination of [177Lu]Lu-PEP49989 and trastuzumab increased the number of complete tumour remissions. The renal and hepatic toxicity was minimal to mild. CONCLUSION: In preclinical studies, [177Lu]Lu-PEP49989 demonstrated favourable biodistribution and a strong antitumour effect, which was further enhanced by co-treatment with trastuzumab.

Knowing the Patient: Understanding Readmission Reasons in Complex Heart Failure.

BACKGROUND: Heart failure (HF) is a complex problem characterized by frequent hospitalizations and high 30-day readmission rates. Researchers studying HF readmission report that patients and clinicians have different perspectives on readmission and preventability when unadjusted for disease severity. OBJECTIVE: The aim of this study was to gather patient, caregiver, nurse, and physician subjective reason(s) for 30-day HF readmission and perceptions of preventability with contextual factors to evaluate differences. METHODS: A convergent, parallel, mixed-methods design was used with interviews and chart reviews to evaluate contextual factors from the current and index hospital stay. Adults readmitted within 30 days of a previous inpatient stay with a coded HF diagnosis were enrolled and interviewed, followed by interviews with associated caregivers, attending physicians, and assigned nurses. RESULTS: Interviews were conducted with patients (n = 44), caregivers (n = 6), physicians (n = 24), and nurses (n = 44). Readmissions were emergent/urgent (95%) and occurred within 14.9 days (SD, 8.1; 2-28 days) on average after discharge. Index stay coding revealed that most patients (73%) had a high severity of illness (73%) and risk of mortality (68%). Heart failure stage was inconsistently documented. Patients reported acute symptomatic reasons, with only 32% describing readmission as preventable. Physicians reported diagnostic reasons, 38% of which were preventable. Nurses reported behavioral reasons, with 59% being preventable. Patient/clinician agreement on readmission reason was low (30%). CONCLUSIONS: Patient/clinician perspectives on readmission varied among the patients with complex HF. Care planning based on HF stage and other contextual factors is needed to ensure a shared understanding of disease severity and a tailored symptom management approach to prevent readmission.

Using the health belief model to assess racial/ethnic disparities in cancer-related behaviors in an NCI-designated comprehensive cancer center catchment area.

BACKGROUND: Racial and ethnic minorities experience well-documented disparities across the cancer trajectory. However, factors underlying these disparities may vary regionally. The Health Belief Model (HBM) was developed to explain and predict health-related prevention and early detection behaviors, particularly uptake of health services. Our goal was to use the HBM to guide an exploration of factors that contribute to racial/ethnic health disparities in the catchment area of a large National Cancer Institute-designated Comprehensive Cancer Center in the Southeastern United States. METHODS: We conducted a secondary analysis of data collected by the cancer center for its triennial Community Health Needs Assessment, which sampled adults from the center's 15-county catchment area. White non-Hispanics (WNHs; n = 887), Black non-Hispanics (BNHs; n = 78), Hispanics/Latinxs (H/Ls; n = 185), and those identifying as another race/ethnicity ("Others"; n = 39) were compared across key HBM variables, including demographic/psychosocial information, perceived benefits and barriers to preventive health behaviors, risk perception, and health behavior outcomes. RESULTS: Controlling for annual household income, relationship status, and age (for certain screening behaviors), significant differences were seen in information-seeking behaviors, risk perception, community attributes, discrimination, and distress. Non-WNH groups reported worse community attributes, higher everyday discrimination, lower health literacy, less confidence in their ability to get health information, and lower perceived risk of cancer. CONCLUSION: This analysis presents a better understanding of how HBM factors may influence health disparities in the cancer center's catchment area. Results describe the needs of community members from racial and ethnic minority groups, which will inform future research, education, outreach, and service activities.

Surveillance on the endemic of Zika virus infection by meteorological factors in Colombia: a population-based spatial and temporal study.

BACKGROUND: Zika virus (ZIKV) infection is a pandemic and a public health emergency. It is transmitted by mosquitoes, primarily the Aedes genus. In light of no treatment currently, it is crucial to develop effective vector control programs to prevent the spread of ZIKV infection earlier when observing possible risk factors, such as weather conditions enhancing mosquito breeding and surviving. METHODS: This study collected daily meteorological measurements and weekly ZIKV infectious cases among 32 departments of Colombia from January 2015-December 2016. This study applied the distributed lag nonlinear model to estimate the association between the number of ZIKA virus infection and meteorological measurements, controlling for spatial and temporal variations. We examined at most three meteorological factors with 20 lags in weeks in the model. RESULTS: Average humidity, total rainfall, and maximum temperature were more predictable of ZIKV infection outbreaks than other meteorological factors. Our models can detect significantly lagged effects of average humidity, total rainfall, and maximum temperature on outbreaks up to 15, 14, and 20 weeks, respectively. The spatial analysis identified 12 departments with a significant threat of ZIKV, and eight of those high-risk departments were located between the Equator and 6°N. The outbreak prediction also performed well in identified high-risk departments. CONCLUSION: Our results demonstrate that meteorological factors could be used for predicting ZIKV epidemics. Building an early warning surveillance system is important for preventing ZIKV infection, particularly in endemic areas.

Half-life extension via ABD-fusion leads to higher tumor uptake of an affibody-drug conjugate compared to PAS- and XTENylation.

A critical parameter during the development of protein therapeutics is to endow them with suitable pharmacokinetic and pharmacodynamic properties. Small protein drugs are quickly eliminated by kidney filtration, and in vivo half-life extension is therefore often desired. Here, different half-life extension technologies were studied where PAS polypeptides (PAS300, PAS600), XTEN polypeptides (XTEN288, XTEN576), and an albumin binding domain (ABD) were compared for half-life extension of an anti-human epidermal growth factor receptor 2 (HER2) affibody-drug conjugate. The results showed that extension with the PAS or XTEN polypeptides or the addition of the ABD lowered the affinity for HER2 to some extent but did not negatively affect the cytotoxic potential. The half-lives in mice ranged from 7.3 h for the construct including PAS300 to 11.6 h for the construct including PAS600. The highest absolute tumor uptake was found for the construct including the ABD, which was 60 to 160% higher than the PASylated or XTENylated constructs, even though it did not have the longest half-life (9.0 h). A comparison of the tumor-to-normal-organ ratios showed the best overall performance of the ABD-fused construct. In conclusion, PASylation, XTENylation, and the addition of an ABD are viable strategies for half-life extension of affibody-drug conjugates, with the best performance observed for the construct including the ABD.

Characteristics of patients with hematologic malignancies without seroconversion post-COVID-19 third vaccine dosing.

Objectives: The objective of this study is to explore the characteristics of the subset of patients with hematologic malignancies (HMs) who had little to no change in SARS-CoV-2 spike antibody index value levels after a third mRNA vaccine dose (3V) and to compare the cohort of patients who did and did not seroconvert post-3V to get a better understanding of the demographics and potential drivers of serostatus. Study design: This retrospective cohort study analyzed SARS-CoV-2 spike IgG antibody index values pre and post the 3V data on 625 patients diagnosed with HM across a large Midwestern United States healthcare system between 31 October 2019 and 31 January 2022. Methods: To assess the association between individual characteristics and seroconversion status, patients were placed into two groups based on IgG antibody status pre and post the 3V dose, (-/+) and (-/-). Odds ratios were used as measures of association for all categorical variables. Logistic regressions were used to measure the association between HM condition and seroconversion. Results: HM diagnosis was significantly associated with seroconversion status (P = 0.0003) with patients non-Hodgkin lymphoma six times the odds of not seroconverting compared with multiple myeloma patients (P = 0.0010). Among the participants who were seronegative prior to 3V, 149 (55.6%) seroconverted after the 3V dose and 119 (44.4%) did not. Conclusion: This study focuses on an important subset of patients with HM who are not seroconverting after the COVID mRNA 3V. This gain in scientific knowledge is needed for clinicians to target and counsel these vulnerable patients.

Real-World Third COVID-19 Vaccine Dosing and Antibody Response in Patients With Hematologic Malignancies.

Purpose: This study sought to describe the changes in immune response to a third dose of either Pfizer's or Moderna's COVID-19 mRNA vaccine (3V) among patients with hematologic malignancies, as well as associated characteristics. Methods: This retrospective cohort study analyzed pre-3V and post-3V data on 493 patients diagnosed with hematologic malignancies across a large Midwestern health system between August 28, 2021, and November 1, 2021. For antibody testing, S1 spike antigen of the SARS-CoV-2 virus titer was used to determine serostatus. Results: Among 493 participants, 274 (55.6%) were seropositive both pre- and post-3V (+/+) while 115 (23.3%) seroconverted to positive from prior negative following the third dose (-/+). The remaining 104 (21.1%) were seronegative both before and after 3V (-/-). No participant was seropositive pre-3V and seronegative post-3V (+/-). Results showed a statistically significant increase in the proportion of seropositivity after receiving a third COVID-19 vaccine (P<0.00001). Response to 3V was significantly associated with the 3V vaccine type (P=0.0006), previous COVID-19 infection (P=0.0453), and malignancy diagnosis (P<0.0001). Likelihood of seroconversion (-/+) after 3V was higher in the group of patients with multiple myeloma or related disorders compared to patients with lymphoid leukemias (odds ratio: 8.22, 95% CI: 2.12-31.79; P=0.0008). Conclusions: A third COVID-19 vaccination is effective in producing measurable seroconversion in many patients with hematologic malignancies. Oncologists should actively encourage all their patients, especially those with multiple myeloma, to receive a 3V, given the high likelihood of seroconversion.

Biologic Evaluation of a Heterodimeric HER2-Albumin Targeted Affibody Molecule Produced by Chemo-Enzymatic Peptide Synthesis.

Targeted molecular radiation therapy is a promising emerging treatment modality in oncology, and peptide synthesis may shorten the time to reach the clinical stage. In this study, we have explored Chemo-Enzymatic Peptide Synthesis, or CEPS, as a new means of producing a therapeutic HER2 targeted Affibody® molecule, comprising a C-terminal albumin binding domain (ABD) for half-life extension and a total length of 108 amino acids. In addition, a DOTA moiety could be incorporated at N-terminus directly during the synthesis step and subsequently utilized for site-specific radiolabeling with the therapeutic radionuclide 177Lu. Retained thermodynamic stability as well as retained binding to both HER2 and albumin was verified. Furthermore, HER2 binding specificity of the radiolabeled Affibody molecule was confirmed by an in vitro saturation assay showing a significantly higher cell-bound activity of SKOV-3 (high HER2 expression) compared with BxPC3 (low HER2 expression), both in the presence and absence of HSA. In vivo evaluation in mice bearing HER2 expressing xenografts also showed specific tumor targeting as well as extended time in circulation and reduced kidney uptake compared with a HER2 targeted Affibody molecule without the ABD moiety. To conclude, we have demonstrated that CEPS can be used for production of Affibody-fusion molecules with retained in vitro and in vivo functionality.