64Cu production via the 68Zn(p,nα)64Cu nuclear reaction: An untapped, cost-effective and high energy production route.

INTRODUCTION: Copper-64 (64Cu, t1/2 = 12.7 h) is a positron emitter well suited for theranostic applications with beta-emitting 67Cu for targeted molecular imaging and radionuclide therapy. The present work aims to evaluate the radionuclidic purity and radiochemistry of 64Cu produced via the 68Zn(p,nα)64Cu nuclear reaction. Macrocyclic chelators DOTA, NOTA, TETA, and prostate-specific membrane antigen ligand PSMA I&T were radiolabeled with purified 64Cu and tested for in vitro stability. [64Cu]Cu-PSMA I&T was used to demonstrate in vivo PET imaging using 64Cu synthesized via the 68Zn(p,nα)64Cu production route and its suitability as a theranostic imaging partner alongside 67Cu therapy. METHODS: 64Cu was produced on a 24 MeV TR-24 cyclotron at a beam energy of 23.5 MeV and currents up to 70 µA using 200 mg 68Zn encapsulated within an aluminum­indium-graphite sealed solid target assembly. 64Cu semi-automated purification was performed using a NEPTIS Mosaic-LC synthesis unit employing CU, TBP, and TK201 (TrisKem) resins. Radionuclidic purity was measured by HPGe gamma spectroscopy, while ICP-OES assessed elemental purity. Radiolabeling was performed with NOTA at room temperature and DOTA, TETA, and PSMA I&T at 95 °C. 64Cu incorporation was studied by radio-TLC. 64Cu in vitro stability of [64Cu]Cu-NOTA, [64Cu]Cu-DOTA, [64Cu]Cu-TETA, and [64Cu]Cu-PSMA I&T was assessed at 37 °C from 0 to 72 h in human blood serum. Preclinical PET imaging was performed at 1, 24, and 48 h post-injection with [64Cu]Cu-PSMA I&T in LNCaP tumor-bearing mice and compared with [68Ga]Ga-PSMA I&T. RESULTS: Maximum purified activity of 4.9 GBq [64Cu]CuCl2 was obtained in 5 mL of pH 2-3 solution, with 2.9 GBq 64Cu concentrated in 0.5 mL. HPGe gamma spectroscopy of purified 64Cu detected <0.3 % co-produced 67Cu at EOB with no other radionuclidic impurities. ICP-OES elemental analysis determined <1 ppm Al, Zn, In, Fe, and Cu in the [64Cu]CuCl2 product. NOTA, DOTA, TETA, and PSMA I&T were radiolabeled with 64Cu, resulting in maximum molar activities of 164 ± 6 GBq/µmol, 155 ± 31 GBq/µmol, 266 ± 34 GBq/µmol, and 117 ± 2 GBq/µmol, respectively. PET imaging in PSMA-expressing LNCaP xenografts resulted in high tumor uptake (SUVmean = 1.65 ± 0.1) using [64Cu]Cu-PSMA I&T, while [68Ga]Ga-PSMA I&T yielded an SUVmean of 0.76 ± 0.14 after 60 min post-injection. CONCLUSIONS: 64Cu was purified in a small volume amenable for radiolabeling, with yields suitable for preclinical and clinical application. The 64Cu production and purification process and the favourable PET imaging properties confirm the 68Zn(p,nα)64Cu nuclear reaction as a viable 64Cu production route for facilities with access to a higher energy proton cyclotron, compared to using expensive 64Ni target material and the 64Ni(p,n)64Cu nuclear reaction. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: Our 64Cu production technique provides an alternative production route with the potential to improve 64Cu availability for preclinical and clinical studies alongside 67Cu therapy.

Theranostic Imaging Surrogates for Targeted Alpha Therapy: Progress in Production, Purification, and Applications.

This article highlights recent developments of SPECT and PET diagnostic imaging surrogates for targeted alpha particle therapy (TAT) radiopharmaceuticals. It outlines the rationale for using imaging surrogates to improve diagnostic-scan accuracy and facilitate research, and the properties an imaging-surrogate candidate should possess. It evaluates the strengths and limitations of each potential imaging surrogate. Thirteen surrogates for TAT are explored: 133La, 132La, 134Ce/134La, and 226Ac for 225Ac TAT; 203Pb for 212Pb TAT; 131Ba for 223Ra and 224Ra TAT; 123I, 124I, 131I and 209At for 211At TAT; 134Ce/134La for 227Th TAT; and 155Tb and 152Tb for 149Tb TAT.

A Theranostic Approach to Imaging and Treating Melanoma with 203Pb/212Pb-Labeled Antibody Targeting Melanin.

Metastatic melanoma is a deadly disease that claims thousands of lives each year despite the introduction of several immunotherapeutic agents into the clinic over the past decade, inspiring the development of novel therapeutics and the exploration of combination therapies. Our investigations target melanin pigment with melanin-specific radiolabeled antibodies as a strategy to treat metastatic melanoma. In this study, a theranostic approach was applied by first labeling a chimeric antibody targeting melanin, c8C3, with the SPECT radionuclide 203Pb for microSPECT/CT imaging of C57Bl6 mice bearing B16-F10 melanoma tumors. Imaging was followed by radioimmunotherapy (RIT), whereby the c8C3 antibody is radiolabeled with a 212Pb/212Bi "in vivo generator", which emits cytotoxic alpha particles. Using microSPECT/CT, we collected sequential images of B16-F10 murine tumors to investigate antibody biodistribution. Treatment with the 212Pb/212Bi-labeled c8C3 antibody demonstrated a dose-response in tumor growth rate in the 5-10 µCi dose range when compared to the untreated and radiolabeled control antibody and a significant prolongation in survival. No hematologic or systemic toxicity of the treatment was observed. However, administration of higher doses resulted in a biphasic tumor dose response, with the efficacy of treatment decreasing when the administered doses exceeded 10 µCi. These results underline the need for more pre-clinical investigation of targeting melanin with 212Pb-labeled antibodies before the clinical utility of such an approach can be assessed.

High-yield cyclotron production of 203Pb using a sealed 205Tl solid target.

INTRODUCTION: 203Pb (t1/2 = 51.9 h, 279 keV (81 %)) is a diagnostic SPECT imaging radionuclide ideally suited for theranostic applications in combination with 212Pb for targeted alpha particle therapy. Our objectives were to develop a high-yield solid target 203Pb cyclotron production route using isotopically enriched 205Tl target material and the 205Tl(p,3n)203Pb reaction as an alternative to lower energy production via the 203Tl(p,n)203Pb reaction. METHODS: 250 mg 205Tl metal (99.9 % isotopic enrichment) was pressed using a hardened stainless steel die. Aluminum target discs were machined with a central depression and annulus groove. The flattened 205Tl pellet was placed into the central depression of the Al disc and a circle of indium wire was laid in the machined annulus surrounding the pellet. An aluminum foil cover was then pressed onto the target disc to create an airtight bond. Targets were irradiated at 23.3 MeV for up to 516 min on a TR-24 cyclotron at currents up to 60 µA to produce 203Pb via the 205Tl(p,3n)203Pb nuclear reaction. Following a cool-down period of >12 h, the target was removed and 205Tl dissolved in 4 M HNO3. A NEPTIS Mosaic-LC synthesis unit performed automated separation using Eichrom Pb resin, and 203Pb was eluted using 8 M HCl or 1 M NH4OAc. 205Tl was diverted to a vial for recovery in an electrolytic cell. 203Pb product radionuclidic purity was assessed by HPGe gamma spectroscopy, while elemental purity was assessed by ICP-OES. Radiolabeling and stability studies were performed with PSC, TCMC, and DOTA chelators, and 203Pb incorporation was verified by radio-TLC analysis. RESULTS: Cyclotron irradiations performed at 60 µA proton beam current and 23.3 MeV (205Tl incident energy) had a 203Pb saturated yield of 4658 ± 62 MBq/µA (n = 3). Automated NEPTIS separation took <4 h from the start of target dissolution to product elution, yielding >85 % decay-corrected [203Pb]PbCl2 with a radionuclidic purity of >99.9 %. Purified [203Pb]PbCl2 yields of up to 12 GBq 203Pb were attained (15.8 GBq at EOB). The [203Pb]PbCl2 and [203Pb]Pb(OAc)2 products contained no detectable radionuclidic impurities besides 201Pb (<0.1 %), and <0.4 ppm stable Pb. 205Tl metal was recovered with a 92 % batch yield. Aliquots of 100 µL [203Pb]Pb(OAc)2 were used for radiolabeling PSC-Bn-NCS, TCMC-NCS, and DOTA-NCS chelators at pH 4.5 and 22 °C for 30 min, with maximum respective molar activities of 461 ± 30 GBq/µmol, 195 ± 37 GBq/µmol, and 83 ± 12 GBq/µmol. PSC, TCMC, and DOTA chelators exhibited >99.9 % incorporation after a 120-hour incubation in human serum at 37 °C. CONCLUSIONS: Nuclear medicine centers with access to higher energy cyclotrons can produce large 203Pb activities sufficient for clinical applications, with a convenient separation technique producing highly pure [203Pb]PbCl2 or [203Pb]Pb(OAc)2 for direct radiolabeling. This represents an attractive route to produce 203Pb for diagnostic SPECT imaging alongside 212Pb targeted alpha particle therapy. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: Our high-yield 203Pb production technique significantly enhances 203Pb production capabilities to meet the growing preclinical and clinical demand for 203Pb radiopharmaceuticals alongside 212Pb target alpha particle therapy.

Good practices for 68Ga radiopharmaceutical production.

BACKGROUND: The radiometal gallium-68 (68Ga) is increasingly used in diagnostic positron emission tomography (PET), with 68Ga-labeled radiopharmaceuticals developed as potential higher-resolution imaging alternatives to traditional 99mTc agents. In precision medicine, PET applications of 68Ga are widespread, with 68Ga radiolabeled to a variety of radiotracers that evaluate perfusion and organ function, and target specific biomarkers found on tumor lesions such as prostate-specific membrane antigen, somatostatin, fibroblast activation protein, bombesin, and melanocortin. MAIN BODY: These 68Ga radiopharmaceuticals include agents such as [68Ga]Ga-macroaggregated albumin for myocardial perfusion evaluation, [68Ga]Ga-PLED for assessing renal function, [68Ga]Ga-t-butyl-HBED for assessing liver function, and [68Ga]Ga-PSMA for tumor imaging. The short half-life, favourable nuclear decay properties, ease of radiolabeling, and convenient availability through germanium-68 (68Ge) generators and cyclotron production routes strongly positions 68Ga for continued growth in clinical deployment. This progress motivates the development of a set of common guidelines and standards for the 68Ga radiopharmaceutical community, and recommendations for centers interested in establishing 68Ga radiopharmaceutical production. CONCLUSION: This review outlines important aspects of 68Ga radiopharmacy, including 68Ga production routes using a 68Ge/68Ga generator or medical cyclotron, standardized 68Ga radiolabeling methods, quality control procedures for clinical 68Ga radiopharmaceuticals, and suggested best practices for centers with established or upcoming 68Ga radiopharmaceutical production. Finally, an outlook on 68Ga radiopharmaceuticals is presented to highlight potential challenges and opportunities facing the community.

Radiolanthanum: Promising theranostic radionuclides for PET, alpha, and Auger-Meitner therapy.

Lanthanum radiometals are well positioned to serve as theranostic PET radiometals for targeted radionuclide therapy. The positron emitters 132La and 133La show promise to serve as unique PET imaging agents for 225Ac targeted alpha-particle therapy, the 134Ce/134La pair has PET imaging potential with both 225Ac and 227Th, and 135La has potential in targeted Auger-Meitner electron therapy. With easily accessible cyclotron production routes, effective and efficient chemical separations, and robust chelation chemistry, these radionuclides are well poised for additional preclinical and clinical PET and targeted radionuclide therapy studies. This review summarizes recent advances in radiolanthanum production and preclinical applications that demonstrate the strong potential of these radionuclides in PET and targeted radionuclide therapy.

Endothelial Unc5B controls blood-brain barrier integrity.

Blood-brain barrier (BBB) integrity is critical for proper function of the central nervous system (CNS). Here, we show that the endothelial Unc5B receptor controls BBB integrity by maintaining Wnt/ß-catenin signaling. Inducible endothelial-specific deletion of Unc5B in adult mice leads to BBB leak from brain capillaries that convert to a barrier-incompetent state with reduced Claudin-5 and increased PLVAP expression. Loss of Unc5B decreases BBB Wnt/ß-catenin signaling, and ß-catenin overexpression rescues Unc5B mutant BBB defects. Mechanistically, the Unc5B ligand Netrin-1 enhances Unc5B interaction with the Wnt co-receptor LRP6, induces its phosphorylation and activates Wnt/ß-catenin downstream signaling. Intravenous delivery of antibodies blocking Netrin-1 binding to Unc5B causes a transient BBB breakdown and disruption of Wnt signaling, followed by neurovascular barrier resealing. These data identify Netrin-1-Unc5B signaling as a ligand-receptor pathway that regulates BBB integrity, with implications for CNS diseases.

Monospecific and bispecific monoclonal SARS-CoV-2 neutralizing antibodies that maintain potency against B.1.617.

COVID-19 pathogen SARS-CoV-2 has infected hundreds of millions and caused over 5 million deaths to date. Although multiple vaccines are available, breakthrough infections occur especially by emerging variants. Effective therapeutic options such as monoclonal antibodies (mAbs) are still critical. Here, we report the development, cryo-EM structures, and functional analyses of mAbs that potently neutralize SARS-CoV-2 variants of concern. By high-throughput single cell sequencing of B cells from spike receptor binding domain (RBD) immunized animals, we identify two highly potent SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity, and generate a bispecific antibody. Lead antibodies show strong inhibitory activity against historical SARS-CoV-2 and several emerging variants of concern. We solve several cryo-EM structures at ~3 Å resolution of these neutralizing antibodies in complex with prefusion spike trimer ectodomain, and reveal distinct epitopes, binding patterns, and conformations. The lead clones also show potent efficacy in vivo against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We also generate and characterize a humanized antibody to facilitate translation and drug development. The humanized clone also has strong potency against both the original virus and the B.1.617.2 Delta variant. These mAbs expand the repertoire of therapeutics against SARS-CoV-2 and emerging variants.

Symptomatic diabetic autonomic neuropathy in type 1 diabetes (T1D): Findings from the T1D exchange.

AIMS: We aimed to evaluate the contemporary prevalence of and risk factors for symptomatic diabetic autonomic neuropathy (DAN) in participants with type 1 diabetes (T1D) enrolled in the T1D Exchange Clinic Registry. METHODS: DAN symptoms and severity were assessed with the Survey of Autonomic Symptoms (SAS) in adults with ≥5 years of T1D participating in the T1D Exchange from years 2010-2017. Associations of demographic, clinical, and laboratory factors with symptomatic DAN were assessed. RESULTS: Of the 4919 eligible T1D participants, 965 (20%) individuals completed the SAS questionnaire [mean age 40 ± 17 years, median diabetes duration 20 years (IQR: 13,34), 64% female, 90% non-Hispanic White, and 82% with private insurance]. DAN symptoms were present in 166 (17%) of responders with 72% experiencing moderate severity symptoms or worse. Symptomatic DAN participants had higher hemoglobin A1c (p = 0.03), longer duration (p = 0.004), were more likely to be female (p = 0.03), and more likely to have lower income (p = 0.03) versus no DAN symptoms. Symptomatic DAN was associated with diabetic peripheral neuropathy (p < 0.0001), smoking (p = 0.002), cardiovascular disease (p = 0.02), depression (p < 0.001), and opioid use (p = 0.004). CONCLUSIONS: DAN symptoms are common in T1D. Socioeconomic factors and psychological comorbidities may contribute to DAN symptoms and should be explored further.

Inhibition of renalase drives tumour rejection by promoting T cell activation.

BACKGROUND: Although programmed cell death protein 1 (PD-1) inhibitors have revolutionised treatment for advanced melanoma, not all patients respond. We previously showed that inhibition of the flavoprotein renalase (RNLS) in preclinical melanoma models decreases tumour growth. We hypothesised that RNLS inhibition promotes tumour rejection by effects on the tumour microenvironment (TME). METHODS: We used two distinct murine melanoma models, studied in RNLS knockout (KO) or wild-type (WT) mice. WT mice were treated with the anti-RNLS antibody, m28, with or without anti-PD-1. 10X single-cell RNA-sequencing was used to identify transcriptional differences between treatment groups, and tumour cell content was interrogated by flow cytometry. Samples from patients treated with immunotherapy were examined for RNLS expression by quantitative immunofluorescence. RESULTS: RNLS KO mice injected with wild-type melanoma cells reject their tumours, supporting the importance of RNLS in cells in the TME. This effect was blunted by anti-cluster of differentiation 3. However, MØ-specific RNLS ablation was insufficient to abrogate tumour formation. Anti-RNLS antibody treatment of melanoma-bearing mice resulted in enhanced T cell infiltration and activation and resulted in immune memory on rechallenging mice with injection of melanoma cells. At the single-cell level, treatment with anti-RNLS antibodies resulted in increased tumour density of MØ, neutrophils and lymphocytes and increased expression of IFNγ and granzyme B in natural killer cells and T cells. Intratumoural Forkhead Box P3 + CD4 cells were decreased. In two distinct murine melanoma models, we showed that melanoma-bearing mice treated with anti-RNLS antibodies plus anti-PD-1 had superior tumour shrinkage and survival than with either treatment alone. Importantly, in pretreatment samples from patients treated with PD-1 inhibitors, high RNLS expression was associated with decreased survival (log-rank P = 0.006), independent of other prognostic variables. CONCLUSIONS: RNLS KO results in melanoma tumour regression in a T-cell-dependent fashion. Anti-RNLS antibodies enhance anti-PD-1 activity in two distinct aggressive murine melanoma models resistant to PD-1 inhibitors, supporting the development of anti-RNLS antibodies with PD-1 inhibitors as a novel approach for melanomas poorly responsive to anti-PD-1.

First In Vivo and Phantom Imaging of Cyclotron-Produced 133La as a Theranostic Radionuclide for 225Ac and 135La.

Theranostic isotope pairs have gained recent clinical interest because they can be labeled to the same tracer and applied for diagnostic and therapeutic purposes. The goals of this study were to investigate cyclotron production of clinically relevant 133La activities using natural and isotopically enriched barium target material, compare fundamental PET phantom imaging characteristics of 133La with those of common PET radionuclides, and demonstrate in vivo preclinical PET tumor imaging using 133La-PSMA-I&T. Methods:133La was produced on a 24-MeV cyclotron using an aluminum-indium sealed target with 150-200 mg of isotopically enriched 135BaCO3, natBaCO3, and natBa metal. A synthesis unit performed barium/lanthanum separation. DOTA, PSMA-I&T, and macropa were radiolabeled with 133La. Derenzo and National Electrical Manufacturers Association phantom imaging was performed with 133La, 132La, and 89Zr and compared with 18F, 68Ga, 44Sc, and 64Cu. In vivo preclinical imaging was performed with 133La-PSMA-I&T on LNCaP tumor-bearing mice. Results: Proton irradiations for 100 µA·min at 23.3 MeV yielded 214 ± 7 MBq of 133La and 28 ± 1 MBq of 135La using 135BaCO3, 59 ± 2 MBq of 133La and 35 ± 1 MBq of 135La using natBaCO3, and 81 ± 3 MBq of 133La and 48 ± 1 MBq of 135La using natBa metal. At 11.9 MeV, 135La yields were 81 ± 2 MBq, 6.8 ± 0.4 MBq, and 9.9 ± 0.5 MBq for 135BaCO3, natBaCO3, and natBa metal. BaCO3 target material recovery was 95.4% ± 1.7%. National Electrical Manufacturers Association and Derenzo phantom imaging demonstrated that 133La PET spatial resolution and scanner recovery coefficients were superior to those of 68Ga and 132La and comparable to those of 89Zr. The apparent molar activity was 130 ± 15 GBq/µmol with DOTA, 73 ± 18 GBq/µmol with PSMA-I&T, and 206 ± 31 GBq/µmol with macropa. Preclinical PET imaging with 133La-PSMA-I&T provided high-resolution tumor visualization with an SUV of 0.97 ± 0.17 at 60 min. Conclusion: With high-yield 133La cyclotron production, recovery of BaCO3 target material, and fundamental imaging characteristics superior to those of 68Ga and 132La, 133La represents a promising radiometal candidate to provide high-resolution PET imaging as a PET/α-therapy theranostic pair with 225Ac or as a PET/Auger electron therapy theranostic pair with 135La.

Monospecific and bispecific monoclonal SARS-CoV-2 neutralizing antibodies that maintain potency against B.1.617.

COVID-19 pathogen SARS-CoV-2 has infected hundreds of millions and caused over 5 million deaths to date. Although multiple vaccines are available, breakthrough infections occur especially by emerging variants. Effective therapeutic options such as monoclonal antibodies (mAbs) are still critical. Here, we report the development, cryo-EM structures, and functional analyses of mAbs that potently neutralize SARS-CoV-2 variants of concern. By high-throughput single cell sequencing of B cells from spike receptor binding domain (RBD) immunized animals, we identified two highly potent SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity, and generated a bispecific antibody. Lead antibodies showed strong inhibitory activity against historical SARS-CoV-2 and several emerging variants of concern. We solved several cryo-EM structures at ∼3 Šresolution of these neutralizing antibodies in complex with prefusion spike trimer ectodomain, and revealed distinct epitopes, binding patterns, and conformations. The lead clones also showed potent efficacy in vivo against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We also generated and characterized a humanized antibody to facilitate translation and drug development. The humanized clone also has strong potency against both the original virus and the B.1.617.2 Delta variant. These mAbs expand the repertoire of therapeutics against SARS-CoV-2 and emerging variants.

High yield cyclotron production of a novel 133/135La theranostic pair for nuclear medicine.

This study reports the high-yield production of a novel 133/135La theranostic pair at a 22 MeV proton beam energy as an attractive alternative to the recently introduced 132/135La pair, demonstrating over an order of magnitude production increase of 133/135La (231 ± 8 MBq 133La and 166 ± 5 MBq 135La at End of Bombardment (EOB)) compared to 11.9 MeV production of 132/135La (0.82 ± 0.06 MBq 132La and 19.0 ± 1.2 MBq 135La) for 500 µA·min irradiations. A new sealed solid cyclotron target is introduced, which is fast to assemble, easy to handle, storable, and contains reusable components. Radiolabeling with macrocyclic chelators DOTA and macropa achieved full incorporation, with respective apparent 133La molar activites of 33 ± 5 GBq/µmol and 30 ± 4 GBq/µmol. PET centers with access to a 22 MeV capable cyclotron could produce clinically-relevant doses of 133/135La, via natBa irradiation, as a standalone theranostic agent for PET imaging and Auger electron therapy. With lower positron energies and less energetic and abundant gamma rays than 68Ga, 44Sc and 132La, 133La appears to be an attractive radiometal candidate for PET applications requiring a higher scanning resolution, a relatively long isotopic half-life, ease of handling, and a low patient dose.

Taking cyclotron 68Ga production to the next level: Expeditious solid target production of 68Ga for preparation of radiotracers.

INTRODUCTION: Gallium-68 is an important radionuclide for positron emission tomography (PET) with steadily increasing applications of 68Ga-based radiopharmaceuticals for clinical use. Current 68Ga sources are primarily 68Ge/68Ga-generators, along with successful attempts of 68Ga production using a cyclotron. This study evaluated cyclotron 68Ga production and automated separation using expeditiously manufactured solid targets, demonstrates an order of magnitude improvement in yield compared to 68Ge/68Ga generators, and presents a convenient alternative to existing cyclotron production processes. A comparison of radiolabeling and preclinical PET imaging was performed with both cyclotron and generator produced 68Ga. METHODS: 100 mg enriched 68Zn (99.3% 68Zn, 0.48% 67Zn, 0.1% 66Zn) pellets pressed on silver discs were bombarded for 20-75 min using 12.5 MeV proton beam energies and 10-30 µA currents. 68Ga was separated using an automated TRASIS AllinOne synthesizer employing AG 50W-X8 and UTEVA resins. Post-separation recovery of the 68Zn by electrolysis yielded 76.7 ± 4.3%. Radionuclidic purity of cyclotron-produced 68Ga was investigated with gamma spectroscopy using a HPGe-detector. Radiolabeling was investigated using the macrocyclic chelator DOTA and the bombesin-derived peptide NOTA-BBN2. PET imaging was performed using [68Ga]Ga-NOTA-BBN2 in a PC3 xenograft model. RESULTS: 600 µA·min fresh and recycled quadruplet 68Zn target irradiations (n = 8) at 12.5 MeV and 30 µA yielded 13.9 ± 1.0 GBq 68Ga; 2200 µA·min irradiations (n = 3) yielded 37.5 ± 1.9 GBq 68Ga. HPGe analysis showed EOB 0.0074% and 0.0084% of total activity of 66Ga and 67Ga, respectively. Metal impurities were 0.06 ± 0.03 µg/GBq Zn, 0.13 ± 0.007 µg/GBq Fe, and 0.02 ± 0.01 µg/GBq Al for cyclotron 68Ga. Cyclotron and 68Ge/68Ga generator 68Ga respective DOTA and NOTA-BBN2 labeling incorporations were 99.4 ± 0.0% and 99.3 ± 0.2%, and 90.4 ± 1.5% and 93.0 ± 3.6% determined by radio-thin layer chromatography (radio-TLC). Preclinical PET imaging comparison between generator and cyclotron produced 68Ga showed identical radiotracer tumor uptake and biodistribution profiles in PC3 tumor bearing mice. CONCLUSIONS: Cyclotron 68Ga production provides highly scalable production with equivalent or superior quality 68Ga to a 68Ge/68Ga generator, while providing identical biodistribution and tumor uptake profiles. Our described targetry is simpler and more cost-effective than existing liquid and solid targetry, enabling a turnkey production system for multi-facility distribution of cyclotron produced 68Ga. The manufacturing simplicity described has potential applications for producing other radiometals such as 44Sc. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: Our cost-effective method of solid target 68Ga production can enhance 68Ga production capabilities to meet the high demand for 68Ga-radiopharmaceuticals for research and clinical use.

Targeted Alpha Therapy: Progress in Radionuclide Production, Radiochemistry, and Applications.

This review outlines the accomplishments and potential developments of targeted alpha (α) particle therapy (TAT). It discusses the therapeutic advantages of the short and highly ionizing path of α-particle emissions; the ability of TAT to complement and provide superior efficacy over existing forms of radiotherapy; the physical decay properties and radiochemistry of common α-emitters, including 225Ac, 213Bi, 224Ra, 212Pb, 227Th, 223Ra, 211At, and 149Tb; the production techniques and proper handling of α-emitters in a radiopharmacy; recent preclinical developments; ongoing and completed clinical trials; and an outlook on the future of TAT.

Transforming Performance of Clinical Trials in Pediatric Type 2 Diabetes: A Consortium Model.

Background: Completing phase 3 trials of new drugs for youth with type 2 diabetes is challenging. The Pediatric Diabetes Consortium (PDC) of U.S. pediatric treatment centers developed a Consortium model to improve the efficiency of successfully completing these trials. Aims and Innovations: An aim of the PDC model is to utilize the resources of the PDC Coordinating Center and Executive Committee to improve study protocols, centralize interactions with sponsors, and oversee the performance of PDC Clinical Centers. Key features include a Consulting Group to improve protocol design; Master Service Agreements between the Coordinating Center and Clinical Centers covering confidentiality agreements and contract language; negotiation of a standard Site Budget with Contract Research Organizations (CROs)/Sponsors that reflect actual Clinical Center costs; Weekly Conference Calls with CROs/sponsors to track progress of Clinical Center launches, Monthly Oversight Calls with investigators and study Coordinators to track Clinical Center performance, discuss enrollment strategies, and identify emerging problems. Successes and Challenges: The Consortium model played a key role in the completion of the pivotal trial of liraglutide for treatment of youth with type 2 diabetes. PDC centers also played a pivotal role in exceeding the projected number of randomized subjects needed by two ongoing studies that are nearing completion. Conclusions: While the Consortium model is still a work in progress, PDC has assisted in the successful launch of new type 2 diabetes studies, and negotiations are in underway for PDC participation in pediatric type 1 diabetes and other diabetes-related studies.

Identification and Validation of a Novel Biologics Target in Triple Negative Breast Cancer.

The goal of this study was to identify a novel target for antibody-drug conjugate (ADC) development in triple negative breast cancer (TNBC), which has limited treatment options, using gene expression datasets and in vitro siRNA/CRISPR and in vivo functional assays. We analyzed 4467 breast cancers and identified GABRP as top expressed gene in TNBC with low expression in most normal tissues. GABRP protein was localized to cell membrane with broad range of receptors/cell (815-53,714) and expressed by nearly half of breast cancers tissues. GABRP gene knockdown inhibited TNBC cell growth and colony formation in vitro and growth of MDA-MB-468 xenografts in nude mice. Commercially available anti-GABRP antibody (5-100 µg/ml) or de novo generated Fabs (20 µg/ml) inhibited TNBC cell growth in vitro. The same antibody conjugated to mertansine (DM1) also showed significant anticancer activity at nanomolar concentrations. Our results indicate that GABRP is a potential novel therapeutic target for ADC development.

Improving Diabetes Control Through Remote Glucose Monitoring in a Diabetes Self-Management Program for Employees of a Health System.

IN BRIEF This study investigates the combination of diabetes education, telehealth, a wireless enabled meter, and medication algorithms to improve care for a targeted population of employees with type 1 or type 2 diabetes. After more than 2 years of follow-up, mean A1C was reduced by 1.8%, and a reduction was observed in cost of care, along with an increase in visits with the managing physician provider. Thus, this study showed improved diabetes control using new technologies to provide remote monitoring and telehealth augmenting the outreach and education provided in a diabetes self-management program.

Structure-Guided Combinatorial Engineering Facilitates Affinity and Specificity Optimization of Anti-CD81 Antibodies.

Hepatitis C viral infection is the major cause of chronic hepatitis that affects as many as 71 million people worldwide. Rather than target the rapidly shifting viruses and their numerous serotypes, four independent antibodies were made to target the host antigen CD81 and were shown to block hepatitis C viral entry. The single-chain variable fragment of each antibody was crystallized in complex with the CD81 large extracellular loop in order to guide affinity maturation of two distinct antibodies by phage display. Affinity maturation of antibodies using phage display has proven to be critical to therapeutic antibody development and typically involves modification of the paratope for increased affinity, improved specificity, enhanced stability or a combination of these traits. One antibody was engineered for increased affinity for human CD81 large extracellular loop that equated to increased efficacy, while the second antibody was engineered for cross-reactivity with cynomolgus CD81 to facilitate animal model testing. The use of structures to guide affinity maturation library design demonstrates the utility of combining structural analysis with phage display technologies.

Sleep in children with type 1 diabetes and their parents in the T1D Exchange.

OBJECTIVES: Sleep has physiological and behavioral impacts on diabetes outcomes, yet little is known about the impact of sleep disturbances in children with type 1 diabetes. The current study sought to characterize sleep in children with type 1 diabetes and in their parents and to examine the associations between child sleep, glycemic control and adherence, parent sleep and well-being, parental fear of hypoglycemia, and nocturnal caregiving behavior. METHODS: Surveys were emailed to parents of 2- to 12-year-old participants in the Type 1 Diabetes (T1D) Exchange clinic registry. Clinical data were obtained from the registry for the 515 respondents. RESULTS: In our sample, 67% of children met criteria for poor sleep quality. Child sleep quality was related to glycemic control (HbA1c of 7.9% [63 mmol/mol] in children with poor sleep quality vs 7.6% [60 mmol/mol] in children with non-poor sleep quality; P < 0.001) but not mean frequency of blood glucose monitoring (BGM) (7.6 times/day vs 7.4 in poor/non-poor quality; P = 0.56). Associations were similar for sleep duration. Children with poor sleep quality were more likely to experience severe hypoglycemia (4% in children with poor sleep quality vs 1% in children with non-poor sleep quality; P = 0.05) and more likely to experience DKA (7% vs 4%, respectively; P < 0.001). Poorer child sleep quality was associated with poorer parental sleep quality, parental well-being, and fear of hypoglycemia (P < 0.001 for all). Child sleep was not related to the use of diabetes-related technology (CGM, insulin pump). CONCLUSIONS: Sleep may be a modifiable factor to improve glycemic control and reduce parental distress.