Synthetic Efforts toward the Synthesis of a Fluorinated Analog of 5-Aminolevulinic Acid: Practical Synthesis of Racemic and Enantiomerically Defined 3-Fluoro-5-aminolevulinic Acid.

In 2017, the FDA authorized 5-aminolevulinic acid (5-ALA) for intraoperative optical imaging of suspected high-grade gliomas. This was the first authorized optical imaging agent for brain tumor surgery to enhance the visualization of malignant tissue. Herein we report the synthesis of a racemic and enantiopure fluorinated analog of 5-ALA, i.e., 3-fluoro-5-aminolevulinic acid (3F-5-ALA). We anticipate that these studies will provide the foundation for the future construction of a fluorine-18-labeled 5-ALA PET tracer to be used for functional and metabolic imaging of gliomas.

Incidence and outcomes of cytomegalovirus reactivation after chimeric antigen receptor T-cell therapy.

ABSTRACT: Cytomegalovirus (CMV) reactivation is a major complication among seropositive allogeneic hematopoietic cell transplantation recipients; however, data on CMV reactivation after chimeric antigen receptor (CAR) T-cell therapy are limited. We report the incidence and outcomes of 95 adult CMV-seropositive patients who received CAR T-cell therapy between February 2018 and February 2023. CMV outcomes were CMV reactivation (any viremia) and clinically significant CMV infection (cs-CMV). Thirty-one patients (33%) had evidence of CMV reactivation (any viremia), and 10 patients (11%) had cs-CMV. The median time from CAR T-cell infusion to CMV reactivation was 19 days (interquartile range [IQR], 9-31). The cumulative incidence of CMV (any viremia) was significantly higher among patients with grade 3 to 4 cytokine release syndrome (67 vs 28%; P = .01), and those who received corticosteroids (39 vs 21%; P = .03), anakinra (56 vs 28%; P = .02), or ≥2 immunosuppressants (41 vs 21%; P = .02). Receipt of corticosteroids (18 vs 0%; P = .004), tocilizumab (14 vs 0%; P = .04), anakinra (33 vs 7%; P = .008), and ≥2 immunosuppressants (20 vs 0%; P = .001) were all associated with cs-CMV. Receiving ≥2 immunosuppressants was associated with a twofold increase in CMV reactivation in multivariate analyses (adjusted odds ratio [aOR], 2.27; 95% confidence interval, 1.1-4.8; P = .03). Overall, the 1-year mortality was significantly higher in those with CMV reactivation (57% vs 23%; P = .001). Immunosuppression, particularly with corticosteroids, for the management of CAR T-cell toxicities, is a major risk factor for CMV reactivation.

Cryopreservation and storage patterns of hematopoietic progenitor stem cells for multiple myeloma.

Autologous hematopoietic stem cell transplantation (HCT) has been a standard of care treatment for eligible patients with newly diagnosed multiple myeloma (MM). Guidelines generally recommend hematopoietic progenitor cell (HPC) harvest for two potential HCT. There is a paucity of data reporting use of such collections in the era of novel approved therapies. In this single-center retrospective study, our goal was to determine the HPC utilization rate and costs associated with leukocytapheresis, collection, storage, and disposal to guide future HPC collection planning. We included 613 patients with MM who underwent HPC collection over a nine-year period. The patients were separated into four groups based on HPC utilization: 1) patients who never proceeded to HCT, or Harvest and Hold (14.8 %), 2) patients who proceeded to one HCT with banked HPC remaining (76.8 %), 3) patients who proceeded to one HCT without HPC remaining (5.1 %), and 4) patients who proceeded to two HCTs (3.3 %). After collection, 73.9 % of patients underwent HCT within 30 days. Of patients with banked HPC, defined as not undergoing HCT within 30 days of leukocytapheresis, the overall utilization rate was 14.9 %. At 2- and 5-years post HPC collection, utilization rate was 10.4 % and 11.5 %, respectively. In conclusion, our results suggest very low utilization of stored HPC, raising into question the current HPC collection targets. Given advances in MM therapy, as well as significant costs associated with harvest and storage, collection for unplanned future use warrants reconsideration. As a result of our analysis, our institution has reduced our HPC collection targets.

Impact of 18 F-Fluciclovine PET/CT Findings on Failure-Free Survival in Biochemical Recurrence of Prostate Cancer Following Salvage Radiation Therapy.

PURPOSE: We aimed to evaluate the impact of 18 F-fluciclovine PET/CT imaging on failure-free survival (FFS) post-salvage radiotherapy (SRT) for prostate cancer (PCa) recurrence. METHODS: Seventy-nine patients were recruited in a phase 2/3 clinical trial to undergo 18 F-fluciclovine PET/CT before SRT for PCa. Four patients with extrapelvic disease were excluded. All patients were followed up at regular intervals up to 48 months. Treatment failure was defined as a serum prostate-specific antigen level of ≥0.2 ng/mL above the nadir after SRT, confirmed with an additional measurement, requiring systemic treatment or clinical progression. Failure-free survival was computed and compared between patients grouped according to 18 F-fluciclovine PET/CT imaging findings. RESULTS: Eighty percent (60/75) of patients had a positive finding on 18 F-fluciclovine PET/CT, of which 56.7% (34/60) had prostate bed-only uptake, whereas 43.3% (26/60) had pelvic nodal ± bed uptake. Following SRT, disease failure was detected in 36% (27/75) of patients. There was a significant difference in FFS between patients who had a positive versus negative scan (62.3% vs 92.9% [ P < 0.001] at 36 months and 59.4% vs 92.9% [ P < 0.001] at 48 months). Similarly, there was a significant difference in FFS between patients with uptake in pelvic nodes ± bed versus prostate bed only at 36 months (49.8% vs 70.7%; P = 0.003) and at 48 months (49.8% vs 65.6%; P = 0.040). Failure-free survival was also significantly higher in patients with either negative PET/CT or prostate bed-only disease versus those with pelvic nodal ± prostate bed disease at 36 (78% vs 49.8%, P < 0.001) and 48 months (74.4% vs 49.8%, P < 0.001). CONCLUSIONS: Findings on pre-SRT 18 F-fluciclovine PET/CT imaging, even when acted upon to optimize the treatment decisions and treatment planning, are predictive of post-SRT FFS in men who experience PCa recurrence after radical prostatectomy. A negative 18 F-fluciclovine PET/CT is most predictive of a lower risk of failure, whereas the presence of pelvic nodal recurrence portends a higher risk of SRT failure.

Differences in Failure-Free Survival After Salvage Radiotherapy Guided by Conventional Imaging Versus 18F-Fluciclovine PET/CT in Postprostatectomy Patients: A Post Hoc Substratification Analysis of the EMPIRE-1 Trial.

The EMPIRE-1 (Emory Molecular Prostate Imaging for Radiotherapy Enhancement 1) trial reported a survival advantage in recurrent prostate cancer salvage radiotherapy (SRT) guided by 18F-fluciclovine PET/CT versus conventional imaging. We performed a post hoc analysis of the EMPIRE-1 cohort stratified by protocol-specified criteria, comparing failure-free survival (FFS) between study arms. Methods: EMPIRE-1 randomized patients to SRT planning via either conventional imaging only (bone scanning plus abdominopelvic CT or MRI) (arm A) or conventional imaging plus 18F-fluciclovine PET/CT (arm B). Randomization was stratified by prostate-specific antigen (PSA) level (<2.0 vs. ≥ 2.0 ng/mL), adverse pathology, and androgen-deprivation therapy (ADT) intent. We subdivided patients in each arm using the randomization stratification criteria and compared FFS between patient subgroups across study arms. Results: Eighty-one and 76 patients received per-protocol SRT in study arms A and B, respectively. The median follow-up was 3.5 y (95% CI, 3.0-4.0). FFS was 63.0% and 51.2% at 36 and 48 mo, respectively, in arm A and 75.5% at both 36 and 48 mo in arm B. Among patients with a PSA of less than 2 ng/mL (mean, 0.42 ± 0.42 ng/mL), significantly higher FFS was seen in arm B than arm A at 36 mo (83.2% [95% CI, 70.0-91.0] vs. 66.5% [95% CI, 51.6-77.8], P < 0.001) and 48 mo (83.2% [95% CI, 70.0-91.0] vs. 56.2% [95% CI, 40.5-69.2], P < 0.001). No significant difference in FFS between study arms in patients with a PSA of at least 2 ng/mL was observed. Among patients with adverse pathology, significantly higher FFS was seen in arm B than arm A at 48 mo (68.9% [95% CI, 52.1-80.8] vs. 42.8% [95% CI, 26.2-58.3], P < 0.001) though not at the 36-mo follow-up. FFS was higher in patients without adverse pathology in arm B versus arm A (90.2% [95% CI, 65.9-97.5] vs. 73.1% [95% CI, 42.9-89.0], P = 0.006) at both 36 and 48 mo. Patients in whom ADT was intended in arm B had higher FFS than those in arm A, with the difference reaching statistical significance at 48 mo (65.2% [95% CI, 40.3-81.7] vs. 29.1 [95% CI, 6.5-57.2], P < 0.001). Patients without ADT intent in arm B had significantly higher FFS than patients in arm A at 36 mo (80.7% [95% CI, 64.9-90.0] vs. 68.0% [95% CI, 51.1-80.2]) and 48 mo (80.7% [95% CI, 64.9-90.0] vs. 58.6% [95% CI, 41.0-72.6]). Conclusion: The survival advantage due to the addition of 18F-fluciclovine PET/CT to SRT planning is maintained regardless of the presence of adverse pathology or ADT intent. Including 18F-fluciclovine PET/CT to SRT leads to survival benefits in patients with a PSA of less than 2 ng/mL but not in patients with a PSA of 2 ng/mL or higher.

Improved GRFS after posttransplant cyclophosphamide-based vs ATG-based HLA-mismatched unrelated donor transplant.

A common method to prevent graft-versus-host disease after allogeneic hematopoietic cell transplantation (HCT) from an HLA-mismatched unrelated donor (MMUD) is tacrolimus, methotrexate, and antithymocyte globulin (ATG). The use of posttransplant cyclophosphamide (PTCy) showed promise in a prospective trial for MMUD HCT. We compared 1-year graft-versus-host disease-free, relapse-free survival (GRFS) in 128 recipients of prophylaxis based on tacrolimus/methotrexate/ATG (ATG group, n = 46) vs PTCy, mycophenolate mofetil, and tacrolimus or sirolimus (PTCy group, n = 82) after MMUD HCT. Patients receiving HCT from a MMUD mismatched at ≥1 locus among HLA-A, HLA-B, HLA-C, and HLA-DRB1 were included. The 2 groups were well matched for HCT indication, high-risk disease, and HCT comorbidity index, whereas more patients on PTCy received bone marrow (50% vs 26%; P = .01) and >1 locus HLA-mismatched (30.5% vs 2.2%; P = .001) grafts. The 1-year GRFS was 16% (95% confidence interval (CI): 8%-31%) vs 54% (95% CI: 44%-66%; P < .001) in the ATG and PTCy groups, respectively. The multivariable adjusted hazard ratio for GRFS was 0.34 (95% CI: 0.21-0.55; P < .001) with the use of PTCy. The 1-year overall survival in the ATG group was 45% (95% CI: 32%-62%) vs 75% (95% CI: 66%-85%) in the PTCy group (P < .001). Relapse incidence was similar. One-year nonrelapse mortality was greater after ATG-based prophylaxis: 38% (95% CI: 23%-52%) vs 16% (95 CI: 9%-25%), P < .001. In summary, PTCy-based prophylaxis resulted in superior GRFS and overall survival in recipients of MMUD.

Plasticity of Extrachromosomal and Intrachromosomal BRAF Amplifications in Overcoming Targeted Therapy Dosage Challenges.

Focal amplifications (FA) can mediate targeted therapy resistance in cancer. Understanding the structure and dynamics of FAs is critical for designing treatments that overcome plasticity-mediated resistance. We developed a melanoma model of dual MAPK inhibitor (MAPKi) resistance that bears BRAFV600 amplifications through either extrachromosomal DNA (ecDNA)/double minutes (DM) or intrachromosomal homogenously staining regions (HSR). Cells harboring BRAFV600E FAs displayed mode switching between DMs and HSRs, from both de novo genetic changes and selection of preexisting subpopulations. Plasticity is not exclusive to ecDNAs, as cells harboring HSRs exhibit drug addiction-driven structural loss of BRAF amplicons upon dose reduction. FA mechanisms can couple with kinase domain duplications and alternative splicing to enhance resistance. Drug-responsive amplicon plasticity is observed in the clinic and can involve other MAPK pathway genes, such as RAF1 and NRAS. BRAF FA-mediated dual MAPKi-resistant cells are more sensitive to proferroptotic drugs, extending the spectrum of ferroptosis sensitivity in MAPKi resistance beyond cases of dedifferentiation. SIGNIFICANCE: Understanding the structure and dynamics of oncogene amplifications is critical for overcoming tumor relapse. BRAF amplifications are highly plastic under MAPKi dosage challenges in melanoma, through involvement of de novo genomic alterations, even in the HSR mode. Moreover, BRAF FA-driven, dual MAPKi-resistant cells extend the spectrum of resistance-linked ferroptosis sensitivity. This article is highlighted in the In This Issue feature, p. 873.

Lower Incidence of Cytomegalovirus Reactivation Following Post-Transplantation Cyclophosphamide HLA-Mismatched Unrelated Donor Transplantation.

The use of haploidentical or HLA-mismatched unrelated donors (MMUD) allows allogeneic hematopoietic cell transplantation in individuals without suitable matched donors. Post-transplantation cyclophosphamide (PTCy) is used routinely for prevention of graft-versus-host disease in recipients of haploidentical transplants, and its use has been recently explored in MMUD transplantation. We compared the incidence of cytomegalovirus (CMV) reactivation and rate of lymphocyte recovery between PTCy MMUD and alternative transplantation modalities. Single-center retrospective study of 22 consecutive PTCy MMUD recipients transplanted between April 2017 and January 2019. Patients undergoing anti-thymocyte globulin (ATG) MMUD (n = 37) and PTCy haploidentical transplantation (n = 19) between January 2015 and July 2018 served as historical controls. We assessed the incidence of CMV (any viremia) and clinically significant CMV reactivation (cs-CMVi; defined as CMV disease or CMV viremia leading to preemptive treatment) in these 3 groups. Immune reconstitution was assessed by absolute lymphocyte count (ALC) at days 30, 90, 180, and 360 after transplantation. Statistical analyses included Kaplan-Meier plots with a log-rank test, Kruskal-Wallis test, and Fisher's exact test where appropriate, and logistic regression analyses. For PTCy MMUD, PTCy haploidentical and ATG MMUD groups, the 100-day and 200-day incidence of CMV (any viremia) were 41%, 63%, and 77% (P = .02), and 64%, 68%, and 86% (P = .049), respectively. The rate of cs-CMVi was also lower in PTCy MMUD compared to PTCy haploidentical and ATG MMUD (14% versus 53% and 54% at day 100 [P = .01] and 25% versus 53% and 58% at day 200 [P = .03]). There was a trend toward lower 200-day incidence of cs-CMVi in PTCy MMUD compared to ATG MMUD, even after excluding letermovir-treated patients from the analysis (25% versus 58% [P = .06]). The association between PTCy MMUD and lower risk of cs-CMVi remained significant even after adjusting for letermovir prophylaxis (odds ratio = 0.23, 95% confidence interval, 0.07-0.81 [P = .02]). Day 30 ALC was lower in PTCy MMUD compared to PTCy haploidentical and ATG MMUD (0.14, 0.33, 0.44 × 109/L, respectively [P = .005) but similar across groups at other time points. PTCy MMUD transplantation was associated with lower incidence of CMV events, independent of the use of CMV prophylaxis. Larger studies are needed.

Targeting HIF-activated collagen prolyl 4-hydroxylase expression disrupts collagen deposition and blocks primary and metastatic uveal melanoma growth.

Uveal melanoma (UM) is the most prevalent primary intraocular malignancy in adults, and patients that develop metastases (~50%) survive <1 year, highlighting the urgent need for new therapies. TCGA has recently revealed that a hypoxia gene signature is associated with poor UM patient prognosis. Here we show that expression of hypoxia-regulated collagen prolyl-4-hydroxylase genes P4HA1 and P4HA2 is significantly upregulated in UM patients with metastatic disease and correlates with poor prognosis, suggesting these enzymes might be key tumor drivers. We targeted hypoxia-induced expression of P4HA1/2 in UM with KCN1, a hypoxia inducible factor-1 (HIF-1) pathway inhibitor and found potent inhibition of primary and metastatic disease and extension of animal survival, without overt side effects. At the molecular level, KCN1 antagonized hypoxia-induced expression of P4HA1 and P4HA2, which regulate collagen maturation and deposition in the extracellular matrix. The treatment decreased prolyl hydroxylation, induced proteolytic cleavage and rendered a disordered structure to collagen VI, the main collagen produced by UM, and reduced UM cell invasion. Together, these data demonstrate that extracellular collagen matrix formation can be targeted in UM by inhibiting hypoxia-induced P4HA1 and P4HA2 expression, warranting further development of this strategy in patients with uveal melanoma.

Synthesis, Radiolabeling, and Biological Evaluation of the trans-Stereoisomers of 1-Amino-3-(fluoro-18F)-4-fluorocyclopentane-1-carboxylic Acid as PET Imaging Agents.

The enantiomeric non-natural cyclic amino acids (3R,4R)-1-amino-3-fluoro-4-(fluoro-18F)cyclopentane-1-carboxylic acid and (3S,4S)-1-amino-3-fluoro-4-(fluoro-18F)cyclopentane-1-carboxylic acid ([ 18 F]5) have been prepared as a racemic mixture in 1.3% decay corrected radiochemical yield and in greater than 99% radiochemical purity. [ 18 F]5 is transported primarily via system L with some transport occurring via system ASC, as assessed in rat 9L gliosarcoma, human U87 ΔEGFR glioblastoma, and human DU145 androgen-independent prostate carcinoma tumor cells. In rats bearing intracranial 9L gliosarcoma, [ 18 F]5 gave tumor to contralateral brain tissue ratios of up to 2.8. Biodistribution studies in healthy rats demonstrated that bladder accumulation is delayed until 10 min postinjection.

18F-fluciclovine-PET/CT imaging versus conventional imaging alone to guide postprostatectomy salvage radiotherapy for prostate cancer (EMPIRE-1): a single centre, open-label, phase 2/3 randomised controlled trial.

BACKGROUND: Molecular imaging is increasingly used to guide treatment decisions and planning in prostate cancer. We aimed to evaluate the role of 18F-fluciclovine-PET/CT in improving cancer control compared with conventional imaging (bone scan and either CT or MRI) alone for salvage postprostatectomy radiotherapy. METHODS: In EMPIRE-1, a single-centre, open-label, phase 2/3 randomised controlled trial, patients with prostate cancer with detectable PSA after prostatectomy and negative conventional imaging (no extrapelvic or bone findings) were randomly assigned in a 1:1 ratio to radiotherapy directed by conventional imaging alone or to conventional imaging plus 18F-fluciclovine-PET/CT. Computer-generated randomisation was stratified by PSA concentration, adverse pathology indicators, and androgen deprivation therapy intent. In the 18F-fluciclovine-PET/CT group, radiotherapy decisions were rigidly determined by PET findings, which were also used for target delineation. The primary endpoint was 3 year event-free survival, with events defined as biochemical or clinical recurrence or progression, or initiation of systemic therapy, using univariate and multivariable analyses in patients who received radiotherapy. This trial is registered with ClinicalTrials.gov, NCT01666808 and is closed to new participants. FINDINGS: From Sept 18, 2012, to March 4, 2019, 165 patients were randomly assigned, with median follow-up of 3·52 years (95% CI 2·98-3·95). PET findings resulted in four patients in the 18F-fluciclovine-PET/CT group having radiotherapy aborted; these patients were excluded from survival analyses. Median survival was not reached (95% CI 35·2-not reached; 33% of 81 patients had events) in the conventional imaging group compared with not reached (95% CI not reached-not reached; 20% of 76 patients) in the 18F-fluciclovine-PET/CT group, and 3 year event-free survival was 63·0% (95% CI 49·2-74·0) in the conventional imaging group versus 75·5% (95% CI 62·5-84·6) for 18F-fluciclovine-PET/CT (difference 12·5; 95% CI 4·3-20·8; p=0·0028). In adjusted analyses, study group (hazard ratio 2·04 [95% CI 1·06-3·93], p=0·0327) was significantly associated with event-free survival. Toxicity was similar in both study groups, with the most common adverse events being late urinary frequency or urgency (37 [46%] of 81 patients in the conventional imaging group and 31 [41%] of 76 in the PET group), and acute diarrhoea (11 [14%] in the conventional imaging group and 16 [21%] in the PET group). INTERPRETATION: Inclusion of 18F-fluciclovine-PET into postprostatectomy radiotherapy decision making and planning significantly improved survival free from biochemical recurrence or persistence. Integration of novel PET radiotracers into radiotherapy decisions and planning for prostate cancer patients warrants further study. FUNDING: National Institutes of Health/National Cancer Institute, Blue Earth Diagnostics, and Winship Cancer Institute of Emory University.

Clinical presentation and outcomes of COVID-19 following hematopoietic cell transplantation and cellular therapy.

BACKGROUND: One year into the pandemic, published data on hematopoietic cell transplantation (HCT) recipients with coronavirus disease 2019 (COVID-19) remain limited. METHODS: Single-center retrospective cohort study of adult HCT recipients with polymerase chain reaction (PCR)-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. RESULTS: Twenty-eight consecutive transplantation and cellular therapy patients (autologous, n = 12; allogeneic, n = 15; chimeric antigen receptor T-cell therapy [CAR-T], n = 1) with COVID-19 were identified. The median age was 57 years. The median time from HCT to COVID-19 diagnosis was 656 days (interquartile range [IQR], 33-1274). Patients were followed for a median of 59 days (IQR, 40-88). Among assessable patients (n = 19), 10 (53%) had documented virological clearance; median time to clearance was 34 days (range, 21-56). Out of 28, 12 (43%), 6 (21%), and 10 (36%) patients had mild, moderate, and severe/critical disease, respectively. Overall mortality was 25%, nearly identical for autologous and allogeneic HCT, and exclusively seen in hospitalized patients, older than 50 years of age with severe COVID-19. None of the patients with mild (n = 12) or moderate (n = 6) COVID-19 died whereas 7/10 patients (70%) with severe/critical COVID-19 died (P = .0001). Patients diagnosed with COVID-19 within 12 months of HCT exhibited higher mortality (57% vs 14%; P = .04). All-cause 30-day mortality (n = 4) was 14%. A higher proportion of patients who died within 30 days of COVID-19 diagnosis (3/4) were receiving ≥2 immunosuppressants, compared with patients who survived beyond 30 days after COVID-19 diagnosis (2/24; 75% vs. 8%; P = .01). CONCLUSIONS: Mortality in COVID-19 HCT patients is higher than that of the age-comparable general population and largely dependent on age, disease severity, timing from HCT, and intensity of immunosuppression.

Salvage Radiotherapy Management Decisions in Postprostatectomy Patients with Recurrent Prostate Cancer Based on 18F-Fluciclovine PET/CT Guidance.

Imaging with novel PET radiotracers has significantly influenced radiotherapy decision making and radiation planning in patients with recurrent prostate cancer (PCa). The purpose of this analysis was to report the final results for management decision changes based on 18F-fluciclovine PET/CT findings and determine whether the decision change trend remained after completion of accrual. Methods: Patients with detectable prostate-specific antigen (PSA) after prostatectomy were randomized to undergo either conventional imaging (CI) only (arm A) or CI plus 18F-fluciclovine PET/CT (arm B) before radiotherapy. In arm B, positivity rates on CI and 18F-fluciclovine PET/CT for detection of recurrent PCa were determined. Final decisions on whether to offer radiotherapy and whether to include only the prostate bed or also the pelvis in the radiotherapy field were based on 18F-fluciclovine PET/CT findings. Radiotherapy decisions before and after 18F-fluciclovine PET/CT were compared. The statistical significance of decision changes was determined using the Clopper-Pearson (exact) binomial method. Prognostic factors were compared between patients with and without decision changes. Results: All 165 patients enrolled in the study had standard-of-care CI and were initially planned to receive radiotherapy. Sixty-three of 79 (79.7%) patients (median PSA, 0.33 ng/mL) who underwent 18F-fluciclovine PET/CT (arm B) had positive findings. 18F-Fluciclovine PET/CT had a significantly higher positivity rate than CI did for the whole body (79.7% vs. 13.9%; P < 0.001), prostate bed (69.6% vs. 5.1%; P < 0.001), and pelvic lymph nodes (38.0% vs. 10.1%; P < 0.001). Twenty-eight of 79 (35.4%) patients had the overall radiotherapy decision changed after 18F-fluciclovine PET/CT; in 4 of 79 (5.1%), the decision to use radiotherapy was withdrawn because of extrapelvic disease detected on 18F-fluciclovine PET/CT. In 24 of 75 (32.0%) patients with a final decision to undergo radiotherapy, the radiotherapy field was changed. Changes in overall radiotherapy decisions and radiotherapy fields were statistically significant (P < 0.001). Overall, the mean PSA at PET was significantly different between patients with and without radiotherapy decision changes (P = 0.033). Conclusion:18F-Fluciclovine PET/CT significantly altered salvage radiotherapy decisions in patients with recurrent PCa after prostatectomy. Further analysis to determine the impact of 18F-fluciclovine PET/CT guidance on clinical outcomes after radiotherapy is in progress.

[18F]-Fluciclovine PET discrimination of recurrent intracranial metastatic disease from radiation necrosis.

BACKGROUND: Stereotactic radiosurgery (SRS) is often the primary treatment modality for patients with intracranial metastatic disease. Despite advances in magnetic resonance imaging, including use of perfusion and diffusion sequences and molecular imaging, distinguishing radiation necrosis from progressive tumor remains a diagnostic and clinical challenge. We investigated the sensitivity and specificity of 18F-fluciclovine PET to accurately distinguish radiation necrosis from recurrent intracranial metastatic disease in patients who had previously undergone SRS. METHODS: Fluciclovine PET imaging was performed in 8 patients with a total of 15 lesions that had previously undergone SRS and had subsequent MRI and clinical features suspicious for recurrent disease. The SUVmax of each lesion and the contralateral normal brain parenchyma were summated and evaluated at four different time points (5 min, 10 min, 30 min, and 55 min). Lesions were characterized as either recurrent disease (11 of 15 lesions) or radiation necrosis (4 of 15 lesions) and confirmed with histopathological correlation (7 lesions) or through serial MRI studies (8 lesions). RESULTS: Time activity curve analysis found statistically greater radiotracer accumulation for all lesions, including radiation necrosis, when compared to contralateral normal brain. While the mean and median SUVmax for recurrent disease were statistically greater than those of radiation necrosis at all time points, the difference was more significant at the earlier time points (p = 0.004 at 5 min-0.025 at 55 min). Using a SUVmax threshold of ≥ 1.3, fluciclovine PET demonstrated a 100% accuracy in distinguishing recurrent disease from radiation necrosis up to 30 min after injection and an accuracy of 87% (sensitivity = 0.91, specificity = 0.75) at the last time point of 55 min. However, tumor-to-background ratios (TBRmax) were not significantly different between recurrent disease and radiation necrosis at any time point due to variable levels of fluciclovine uptake in the background brain parenchyma. CONCLUSIONS: Fluciclovine PET may play an important role in distinguishing active intracranial metastatic lesions from radiation necrosis in patients previously treated with SRS but needs to be validated in larger studies.

Synthesis, Radiolabeling, and Biological Evaluation of the cis Stereoisomers of 1-Amino-3-Fluoro-4-(fluoro-18F)Cyclopentane-1-Carboxylic Acid as PET Imaging Agents.

The non-natural cyclic amino acids (1S,3R,4S)-1-amino-3-fluoro-4-(fluoro-18F)cyclopentane-1-carboxylic acid ([18F]9) and (1S,3S,4R)-1-amino-3-fluoro-4-(fluoro-18F)cyclopentane-1-carboxylic acid ([18F]28) have been prepared in 10 and 1.7% decay corrected radiochemical yield, respectively, and in greater than 99% radiochemical purity. Cell assays in rat 9L gliosarcoma, human U87 ΔEGFR glioblastoma, and human DU145 androgen-independent prostate carcinoma tumor cells indicated that both compounds are substrates for amino acid transport primarily by system L, with some transport taking place via system ASC. In rats with 9L gliosarcoma, [18F]9 and [18F]28 provided high tumor to normal brain tissue ratios, with maximal ratios of 3.5 and 4.1, respectively. Biodistribution studies in healthy rats confirmed that both compounds are BBB permeable and that bladder accumulation is low until at least 5 min post injection.

Microglia, inflammation and gut microbiota responses in a progressive monkey model of Parkinson's disease: A case series.

Inflammation has been linked to the development of nonmotor symptoms in Parkinson's disease (PD), which greatly impact patients' quality of life and can often precede motor symptoms. Suitable animal models are critical for our understanding of the mechanisms underlying disease and the associated prodromal disturbances. The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkey model is commonly seen as a "gold standard" model that closely mimics the clinical motor symptoms and the nigrostriatal dopaminergic loss of PD, however MPTP toxicity extends to other nondopaminergic regions. Yet, there are limited reports monitoring the MPTP-induced progressive central and peripheral inflammation as well as other nonmotor symptoms such as gastrointestinal function and microbiota. We report 5 cases of progressive parkinsonism in non-human primates to gain a broader understanding of MPTP-induced central and peripheral inflammatory dysfunction to understand the potential role of inflammation in prodromal/pre-motor features of PD-like degeneration. We measured inflammatory proteins in plasma and CSF and performed [18F]FEPPA PET scans to evaluate translocator proteins (TSPO) or microglial activation. Monkeys were also evaluated for working memory and executive function using various behavior tasks and for gastrointestinal hyperpermeability and microbiota composition. Additionally, monkeys were treated with a novel TNF inhibitor XPro1595 (10 mg/kg, n = 3) or vehicle (n = 2) every three days starting 11 weeks after the initiation of MPTP to determine whether XPro1595 would alter inflammation and microglial behavior in a progressive model of PD. The case studies revealed that earlier and robust [18F]FEPPA PET signals resulted in earlier and more severe parkinsonism, which was seen in male cases compared to female cases. Potential other sex differences were observed in circulating inflammation, microbiota diversity and their metabolites. Additional studies with larger group sizes of both sexes would enable confirmation and extension of these findings. If these findings reflect potential differences in humans, these sex differences have significant implications for therapeutic development of inflammatory targets in the clinic.

[18F]Fluciclovine Positron Emission Tomography/Computerized Tomography for Preoperative Staging in Patients with Intermediate to High Risk Primary Prostate Cancer.

PURPOSE: Accurate preoperative staging of prostate cancer is essential for treatment planning. Conventional imaging is limited in detection of metastases. Our primary aim was to determine if [18F]fluciclovine positron emission tomography/computerized tomography is an early indicator of subclinical metastasis among patients with high risk prostate cancer. MATERIALS AND METHODS: A total of 68 patients with unfavorable intermediate to very high risk prostate cancer without systemic disease on conventional imaging were recruited before robotic radical prostatectomy with extended pelvic lymph node dissection. Diagnostic performance of [18F]fluciclovine positron emission tomography/computerized tomography and conventional imaging for detection of metastatic disease, and correlation of positivity to node and metastatic deposit size were determined. RESULTS: Overall 57 of 68 patients completed the protocol, of whom 31 had nodal metastasis on histology. [18F]Fluciclovine positron emission tomography/computerized tomography sensitivity and specificity in detecting nodal metastasis was 55.3% and 84.8% per patient, and 54.8% and 96.4% per region (right and left pelvis, presacral and nonregional), respectively. Compared with conventional imaging [18F]Fluciclovine positron emission tomography/computerized tomography had significantly higher sensitivity on patient based (55.3% vs 33.3%, p <0.01) and region based (54.8% vs 19.4%, p <0.01) analysis, detecting metastasis in 7 more patients and 22 more regions, with similar high specificity. Four additional patients had distant disease or other cancer detected on [18F] fluciclovine positron emission tomography/computerized tomography which precluded surgery. Detection of metastasis was related to size of metastatic deposits within lymph nodes and overall metastatic burden. CONCLUSIONS: [18F]Fluciclovine positron emission tomography/computerized tomography detects occult metastases not identified on conventional imaging and may help guide treatment decisions and lymph node dissection due to high specificity for metastatic disease.

Evaluating the reoperation rate and hardware durability of three stabilizing implants for 105 malignant pathologic humerus fractures.

INTRODUCTION: Many patients sustaining a malignant pathologic humerus fracture (MPHF) elect for surgical stabilization. Complications prompting reoperation can occur, leading to additional quality of life and financial cost. One common event preceding reoperation is a broken implant (BI). The purpose of this study was to identify the rate of reoperation following surgical stabilization of MPHF with three techniques - photodynamic bone stabilization (PBS), intramedullary nail (IMN), and cemented plate fixation (CPF) - and estimate to what extent improved implant durability might prevent reoperation. MATERIALS AND METHODS: Retrospective data collection was performed, identifying 105 procedures (100 patients) who underwent non-articular MPHF surgery from 2010-2016: 19 PBS, 65 IMN, 21 CPF. All patients were followed for at least two years or until death. RESULTS: Reoperation rates were similar at one year (10.5%,6.2%,4.8%, p = 737), two years (15.8%,6.2%,9.5%, p = 375), and final evaluation (15.8%,7.7%,14.3%, p = 248). The rate of BI for PBS, IMN, and CPF was 10.5%,0%, and 4.8% (p = 049 PBS/IMN) at one year, 15.8%,0%, and 9.5% (p = 010 PBS/IMN) at two years, and 15.8%,0%, and 14.3% (p = 010 IMN/PBS, p = 013 IMN/CPF) at final evaluation. CONCLUSIONS: Reoperation rate was not significantly different at any time point. However, IMN surgery resulted in the lowest rate of broken implants (zero), statistically significant versus PBS at all time periods and versus CPF at final follow-up. PBS may eventually offer selected advantages for MPHF management, but current data suggests fragility must be thoughtfully considered.

Incidence and risk factors associated with a syndrome of persistent cytopenias after CAR-T cell therapy (PCTT).

Anti-CD19 Chimeric Antigen Receptor T cells (CAR-T) have shown dramatic efficacy in treating refractory aggressive B cell Lymphomas leading to FDA approval of axicabtagene ciloleucel and tisagenlecleucel. While long-term remission rate for both is higher than 33%, this treatment is associated with life-threatening complications including cytokine-release syndrome, encephalopathy, and lethal cerebral edema. Here we describe a case series of bone marrow failure syndromes with or without co-existing clonal myelodysplastic syndrome. Bone marrow failure was defined as absolute neutrophil count (ANC) <500 neutrophils/µL day 42 after infusion of CAR-T cells or filgrastim support to reach that number. We use "persistent cytopenias after T-cell therapy (PCTT)" to describe this syndrome which has an incidence of 38% with axicabtagene ciloleucel. Platelets <75,000/µL at the time of initiation of lymphodepleting chemotherapy and occurrence of maximum severity of cytokine-release syndrome (CRS) on day 0 or 1 after infusion of CAR-T cells are independent predictors of PCTT.

A benzenesulfonamide derivative as a novel PET radioligand for CXCR4.

CXCR4 is involved in various diseases such as inflammation, tumor growth, and cancer metastasis through the interaction with its natural endogenous ligand, chemokine CXCL12. In an effort to develop imaging probes for CXCR4, we developed a novel small molecule CXCR4-targeted PET agent (compound 5) by combining our established benzenesulfonamide scaffold with a labeling component by virtue of click chemistry. 5 shows nanomolar affinity (IC50 = 6.9 nM) against a known CXCR4 antagonist (TN14003) and inhibits more than 65% chemotaxis at 10 nM in vitro assays. Radiofluorinated compound 5 ([18F]5) demonstrates a competitive cellular uptake against CXCL12 in a dose-dependent manner. Further, microPET images of [18F]5 exhibits preferential accumulation of radioactivity in the lesions of λ-carrageenan-induced paw edema, human head and neck cancer orthotopic xenograft, and metastatic lung cancer of each mouse model.