Adoptive cell therapy for high grade gliomas using simultaneous temozolomide and intracranial mgmt-modified γδ t cells following standard post-resection chemotherapy and radiotherapy: current strategy and future directions

Cellular therapies, including chimeric antigen receptor T cell therapies (CAR-T), while generally successful in hematologic malignancies, face substantial challenges against solid tumors such as glioblastoma (GBM) due to rapid growth, antigen heterogeneity, and inadequate depth of response to cytoreductive and immune therapies, We have previously shown that GBM constitutively express stress associated NKG2D ligands (NKG2DL) recognized by gamma delta (γδ) T cells, a minor lymphocyte subset that innately recognize target molecules via the γδ T cell receptor (TCR), NKG2D, and multiple other mechanisms. Given that NKG2DL expression is often insufficient on GBM cells to elicit a meaningful response to γδ T cell immunotherapy, we then demonstrated that NKG2DL expression can be transiently upregulated by activation of the DNA damage response (DDR) pathway using alkylating agents such as Temozolomide (TMZ). TMZ, however, is also toxic to γδ T cells. Using a p140K/MGMT lentivector, which confers resistance to TMZ by expression of O(6)-methylguanine-DNA-methyltransferase (MGMT), we genetically engineered γδ T cells that maintain full effector function in the presence of therapeutic doses of TMZ. We then validated a therapeutic system that we termed Drug Resistance Immunotherapy (DRI) that combines a standard regimen of TMZ concomitantly with simultaneous intracranial infusion of TMZ-resistant γδ T cells in a first-in-human Phase I clinical trial (NCT04165941). This manuscript will discuss DRI as a rational therapeutic approach to newly diagnosed GBM and the importance of repeated administration of DRI in combination with the standard-of-care Stupp regimen in patients with stable minimal residual disease.

A Computational Study of Tissue Plasminogen Activator (Tpa) and Vanillylamine for Treatment of Heart Stroke

When blood cannot flow to the brain, a stroke occurs. A blockage or burst blood vessel inside the brain is a common culprit for this disturbance in blood flow because they both limit oxygen to the brain tissue. If this happens, the brain's oxygen-starved cells begin to die quickly, so it's important to get medical attention at once for the patient's chances of recovery. The major objective of this study is to investigate potent thrombolytics from natural sources that are used to treat stroke. Natural sources have been found to exhibit thrombolytic action, with active molecules also extracted and described. The ligand strength was confirmed in the present work using the binding energy, which is based on computer-aided molecular modeling. Vanillylamine exhibited a stronger docking score and had greater thrombolytic potency than other drugs. The main objective of this study is to find an effective treatment for heart attacks. The protein and ligand combination had an affinity of -5.40 kcal/mol, which further suggests that it may be employed in future studies to create a potential inhibitor against stroke.

Consumption of Salt in Patients Suffering from Heart Failure

Heart failure is the deadliest medical emergency condition and considered as a global health priority. In order to prevent heart failure disease and death caused by heart failure, the healthcare professionals spreading the awareness among the public. Till now, effective curing of heart failure is still not possible but if patients treated well then it can improve quality of life and survival. Many healthcare professionals recommend taking sodium (in the form of salt) by the heart failure patients. But the consumption of sodium in heart failure patients is still a debatable topic among the healthcare professionals. How much quantity of salt patients’ needs to take is still a question. Excessive salt consumption can cause hypertension and left ventricular hypertrophy and less salt consumption is illogically linked with the poorer heart failure results. This overview discussed about the merits as well as demerits related to the consumption of salt in patients suffering from heart failure.

Phase I study of drug-resistant immunotherapy (DRI) with gene-modified autologous γδ T cells in patients with newly diagnosed glioblastoma multiforme (GBM) receiving maintenance temozolomide (TMZ)

2044

Background: γδ T cells, MHC unrestricted immune cells, target NKG2D ligands differentially expressed on tumor cells. DeltEx drug resistant immunotherapy (DRI), a novel ex vivo expanded, activated γδ T cell expresses MGMT, conveying TMZ resistance. NCT04165941 , a phase 1 trial assessing the safety of single and multiple infusions of autologous DeltEx DRI cells presents updated safety and efficacy data. Methods: Adult newly diagnosed GBM patients with adequate organ function and KPS≥70% are enrolled. Cells engineered from apheresis after tumor resection were infused through a Rickham catheter placed during surgery. Cohort (C) 1, 2 and 3 receive 1, 3 and 6 doses of cells respectively on day (D) 1 of each 28-day maintenance cycle. Patients receive 1 x 107 γδ T cells intratumorally on D1 with 150 mg/m2 of TMZ intravenously with the Stupp regimen. Primary endpoint is safety; secondary endpoints include progression free and overall survival. Immunologic and genomic correlative analyses are being conducted. Dose limiting toxicities (DLTs) are defined as treatment related ≥ grade 3 cardiopulmonary or hepatic toxicity, grade 4 toxicity exceeding 72 hours or neurologic deterioration that exceeds 2 weeks. Results: 12 patients (58% male; median age 66.5 (range: 21-76); 66.7% IDH-WT, 66.7% MGMT unmethylated) were enrolled with 6 dosed (3 in C1, 3 in C2). No patients had DLTs, cytokine release syndrome (CRS), or neurotoxicity. The most common adverse events (AEs) were Grade 1/2 events including fever, leukopenia, nausea, and vomiting attributable to TMZ or radiotherapy. One subject had Grade 3 treatment related AEs of UTI, dehydration, and thrombocytopenia. Three evaluable C1 patients have PFS of 8.3, 11.9, 7.4 months and OS of 15.6, 17.7 and 9.6 months respectively. In C2, three patients have been dosed, with one patient with stable disease at 8.2 months after receiving all three doses and no DLTs. Patient recruitment continues with anticipated completion in 2022. Conclusions: Data demonstrates that single, repeat doses of DRI T cells have manageable toxicity with encouraging trend in PFS.

TROPHY-U-01 Cohort 3: Sacituzumab govitecan (SG) in combination with pembrolizumab (Pembro) in patients (pts) with metastatic urothelial cancer (mUC) who progressed after platinum (PLT)-based regimens

434

Background: Checkpoint inhibitors (CPIs) are standard therapy for pts with mUC after PLT-based regimens, with limited long-term disease control. SG is an antibody-drug conjugate composed of an anti-trophoblast cell-surface antigen 2 (Trop-2) antibody coupled to SN-38 (a topoisomerase-I inhibitor) via a proprietary hydrolyzable linker. In the TROPHY-U-01 registrational phase 2 trial, SG monotherapy demonstrated significant activity and manageable safety in pts with mUC who progressed after prior PLT-based chemotherapy and CPI, with 27% objective response rate (ORR) and median overall survival of 11 months (Tagawa, et al. J Clin Oncol. 2021). Here, we present interim efficacy and safety results of combining SG with Pembro as 2nd-line therapy in CPI-naive pts with mUC who progressed after PLT-based chemotherapy (cohort 3). Methods: TROPHY-U-01 is a multicohort, open-label, global phase 2 trial. Eligible pts had measurable disease, Eastern Cooperative Oncology Group performance status (ECOG PS) 0–1, and creatinine clearance ≥30 mL/min. The recommended phase 2 dose (RP2D) was determined during a 10-pt safety lead-in, and additional pts were enrolled at the RP2D in a Simon 2-stage design. Primary endpoint: ORR by blinded independent central review per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). Key secondary endpoints: investigator-assessed ORR, clinical benefit rate [CBR; complete response (CR) + partial response (PR) + stable disease], progression-free survival (PFS), and safety. Results: At the time of data cutoff, 41 pts received at least a dose of SG at the RP2D (10 mg/kg). Of these 41 pts, median (range) age was 67y (46–86), 83% men, 61% ECOG PS 1, 76% had ≥1 Bellmunt risk factor, and median (range) number of prior anticancer regimens was 1 (1–3). At a median follow-up of 5.8 mo, the investigator-assessed ORR was 34% (95% CI, 20.1–50.6; 1 CR; 13 PR); CBR was 44% (95% CI, 28.5–60.3); 6-mo PFS rate was 47%. Median time to response was 2.0 mo (95% CI, 1.3–2.8). Most common treatment-emergent adverse events (TEAEs) were diarrhea (76%), nausea (59%), anemia (56%), neutropenia (44%), and asthenia (41%). Treatment-related grade ≥3 AEs occurred in 59% of pts. Key grade ≥3 TEAEs of any cause included diarrhea (24%), anemia (20%), febrile neutropenia (10%), fatigue (7%), and asthenia (5%). Two pts discontinued treatment due to treatment-related AEs. No treatment-related death occurred. Conclusions: SG in combination with Pembro demonstrated encouraging ORR and CBR, with an overall manageable safety profile with no new safety signal in CPI-naive pts who progressed after prior PLT-based chemotherapy. The data support further evaluation of SG plus CPI in mUC. Limitations: small sample size, short follow-up, and lack of randomization. Biomarker evaluation is ongoing. Clinical trial information: NCT03547973.

TROPHY-U-01 cohort 4: Sacituzumab govitecan (SG) in combination with cisplatin (Cis) in platinum (PLT)-naïve patients (pts) with metastatic urothelial cancer (mUC)

TPS581

Background: Cis-based combination chemotherapy regimens with gemcitabine or methotrexate, vinblastine, and doxorubicin are commonly used as initial treatment for mUC. However, only a fraction of pts maintain a durable response. Alternative Cis-based combinations with improved efficacy while maintaining tolerability are needed. SG is an antibody-drug conjugate (ADC) composed of an anti-trophoblast cell-surface antigen-2 (Trop-2) antibody coupled to SN-38 (a topoisomerase-I inhibitor) via a proprietary hydrolyzable linker. In vitro/in vivo urinary bladder cancer models suggest that the combination of SG and Cis resulted in additive antitumor activity over either agent alone (data on file). In the phase 2 registrational TROPHY-U-01 study, SG monotherapy resulted in a 27% objective response rate (ORR) and a median overall survival (OS) of 10.9 months with a manageable, mostly non–Cis-overlapping toxicity profile in heavily pretreated pts with mUC (Tagawa et al, J Clin Oncol. 2021). These results led to accelerated approval of SG by the FDA in 2021 for pts with locally advanced or mUC who previously received PLT-containing chemotherapy and a checkpoint inhibitor. We hypothesized that SG and Cis in combination may improve efficacy/safety over available first-line mUC regimens. TROPHY-U-01 Cohort 4 study will evaluate the safety, tolerability, and clinical activity of this novel combination. Methods: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, global phase 2 trial. Cohort 4 will evaluate combination SG and Cis in PLT-naive pts with mUC or unresectable locally advanced disease. Key eligibility requirements include Eastern Cooperative Oncology Group performance status 0–1; no prior anticancer monoclonal antibody or ADC therapy within 4 weeks of study drug initiation; no history of active interstitial lung disease or noninfectious pneumonitis; adequate hematologic, hepatic, and renal function. Pts will be treated with Cis at 70 mg/m2 on day 1 of a 21-day cycle (if creatinine clearance [CrCl] ≥60 mL/min) or at a split dose of Cis at 35 mg/m2 on days 1 and 8 of a 21-day cycle (if CrCl 50-59 mL/min) followed by SG (5, 7.5, or 10 mg/kg) on days 1 and 8 of a 21-day cycle. The recommended phase 2 dose will be the dose in which ≤30% dose-limiting toxicities are noted in cycle 1. Combination therapy will continue for up to 6 cycles, followed by SG and avelumab maintenance given until progression. Prophylactic granulocyte colony-stimulating factor is not allowed in cycle 1 of the safety lead-in phase. Primary endpoint is ORR per RECIST v1.1 by blinded independent central review (BICR). Secondary endpoints include progression-free survival, duration of response, and clinical benefit rate per BICR and investigator assessment. OS and safety will be assessed. Enrollment is ongoing; ̃60 pts expected across ̃30 sites in North America and Europe. Clinical trial information: NCT03547973.

TROPiCS-04: Study of sacituzumab govitecan (SG) in patients (pts) with locally advanced (LA) unresectable or metastatic urothelial cancer (mUC) that has progressed after prior platinum (PLT) and checkpoint inhibitor (CPI) therapy

TPS582

Background: Treatment options are limited for pts with LA unresectable or mUC who progress after prior PLT-based and CPI therapies. SG is an antibody-drug conjugate (ADC) composed of an anti-trophopblast cell surface antigen 2 (Trop-2) antibody coupled to SN-38 (a topoisomerase-I inhibitor) via a proprietary hydrolyzable linker. In the phase 2 registrational study TROPHY-U-01 (NCT03547973), SG demonstrated an objective response rate (ORR) of 27% and median overall survival (OS) of 10.9 months in pts with mUC who progressed after prior PLT-based and CPI therapies (n = 113; median, 3 prior lines of therapy; 84% with ≥1 Bellmunt risk factors; Tagawa et al, J Clin Oncol. 2021). These results compared favorably with historic data for single-agent chemotherapy (ORR, ̃18%; OS, 9 months; Powles et al. J Clin Oncol. 2021) and led to accelerated approval of SG by the US Food and Drug Administration for pts with LA or mUC who previously received a PLT-containing chemotherapy and CPI. The phase 3 TROPiCS-04 trial has been initiated to confirm these findings. Methods: TROPiCS-04 (NCT04527991) is a global, multicenter, open-label, randomized, controlled trial in pts with LA unresectable or mUC who progressed after prior PLT-based and CPI therapies. Key eligibility requirements include Eastern Cooperative Oncology Group performance status 0-1; no prior CPI or ADC therapy within 4 weeks of study drug initiation; no history of active interstitial lung disease or noninfectious pneumonitis; and adequate hematologic, hepatic, and renal function. Pts will be randomly assigned 1:1 to receive SG 10 mg/kg intravenously (IV) on days 1 and 8 of 21-day cycles or single-agent treatment of physician’s choice (paclitaxel 175 mg/m2, docetaxel 75 mg/m2, or vinflunine 320 mg/m2 IV on day 1 of 21-day cycles) until progressive disease, unacceptable toxicity, or withdrawal of consent. Treatment beyond progressive disease may be permitted in pts deemed to be receiving clinical benefit per investigator assessment. Approximately 600 pts will be enrolled across ̃280 sites in 3 regions (North America, Europe, and Asia-Pacific) to provide 90% power on the primary endpoint of OS. Secondary endpoints include progression-free survival, ORR, clinical benefit rate, duration of response (all per Response Evaluation Criteria in Solid Tumors version 1.1 by blinded independent central review and investigator assessment), safety, and quality of life. Study enrollment started in January 2021 and is ongoing with pts currently enrolled at 30 sites across all 3 regions. Clinical trial information: NCT04527991.

TROPHY-U-01: A Phase II Open-Label Study of Sacituzumab Govitecan in Patients With Metastatic Urothelial Carcinoma Progressing After Platinum-Based Chemotherapy and Checkpoint Inhibitors

PURPOSE

Patients with metastatic urothelial carcinoma (mUC) who progress on platinum-based combination chemotherapy (PLT) and checkpoint inhibitors (CPIs) have limited options that offer objective response rates (ORRs) of approximately 10% with a median overall survival (OS) of 7-8 months. Sacituzumab govitecan (SG) is a TROP-2-directed antibody-drug conjugate with an SN-38 payload that has shown preliminary activity in mUC.

METHODS

TROPHY-U-01 (ClinicalTrials.gov identifier: NCT03547973) is a multicohort, open-label, phase II, registrational study. Cohort 1 includes patients with locally advanced or unresectable or mUC who had progressed after prior PLT and CPI. Patients received SG 10 mg/kg on days 1 and 8 of 21-day cycles. The primary outcome was centrally reviewed ORR; secondary outcomes were progression-free survival, OS, duration of response, and safety.

RESULTS

Cohort 1 included 113 patients (78% men; median age, 66 years; 66.4% visceral metastases; median of three [range, 1-8] prior therapies). At a median follow-up of 9.1 months, the ORR was 27% (31 of 113; 95% CI, 19.5 to 36.6); 77% had decrease in measurable disease. Median duration of response was 7.2 months (95% CI, 4.7 to 8.6 months), with median progression-free survival and OS of 5.4 months (95% CI, 3.5 to 7.2 months) and 10.9 months (95% CI, 9.0 to 13.8 months), respectively. Key grade ≥ 3 treatment-related adverse events included neutropenia (35%), leukopenia (18%), anemia (14%), diarrhea (10%), and febrile neutropenia (10%), with 6% discontinuing treatment because of treatment-related adverse events.

CONCLUSION

SG is an active drug with a manageable safety profile with most common toxicities of neutropenia and diarrhea. SG has notable efficacy compared with historical controls in pretreated mUC that has progressed on both prior PLT regimens and CPI. The results from this study supported accelerated approval of SG in this population.

Simulations of single- and two-tone Tm-doped optical fiber laser amplifiers

This work uses numerical simulations of a thulium-doped optical fiber amplifier to predict various performance characteristics such as peak temperatures, expected output powers and efficiencies, presence of amplified spontaneous emission (ASE), and transverse mode instability (TMI) onset power thresholds. Single- and two-tone configurations are studied. In the latter case, the two laser sources are separated in frequency by the amount that corresponds to the peak Raman gain, and a few seed ratios at various total seed powers are examined. The goal is to provide the field with pertinent information on what is feasible for this type of amplifier.

Sacituzumab govitecan, a Trop-2-directed antibody-drug conjugate, for patients with epithelial cancer: final safety and efficacy results from the phase I/II IMMU-132-01 basket trial

BACKGROUND

Sacituzumab govitecan (SG), a trophoblast cell surface antigen-2 (Trop-2)-directed antibody-drug conjugate, has demonstrated antitumor efficacy and acceptable tolerability in a phase I/II multicenter trial (NCT01631552) in patients with advanced epithelial cancers. This report summarizes the safety data from the overall safety population (OSP) and efficacy data, including additional disease cohorts not published previously.

PATIENTS AND METHODS

Patients with refractory metastatic epithelial cancers received intravenous SG (8, 10, 12, or 18 mg/kg) on days 1 and 8 of 21-day cycles until disease progression or unacceptable toxicity. Endpoints for the OSP included safety and pharmacokinetic parameters with investigator-evaluated objective response rate (ORR per RECIST 1.1), duration of response, clinical benefit rate, progression-free survival, and overall survival evaluated for cohorts (n > 10 patients) of small-cell lung, colorectal, esophageal, endometrial, pancreatic ductal adenocarcinoma, and castrate-resistant prostate cancer.

RESULTS

In the OSP (n = 495, median age 61 years, 68% female; UGT1A1∗28 homozygous, n = 46; 9.3%), 41 (8.3%) permanently discontinued treatment due to adverse events (AEs). Most common treatment-related AEs were nausea (62.6%), diarrhea (56.2%), fatigue (48.3%), alopecia (40.4%), and neutropenia (57.8%). Most common treatment-related serious AEs (n = 75; 15.2%) were febrile neutropenia (4.0%) and diarrhea (2.8%). Grade ≥3 neutropenia and febrile neutropenia occurred in 42.4% and 5.3% of patients, respectively. Neutropenia (all grades) was numerically more frequent in UGT1A1∗28 homozygotes (28/46; 60.9%) than heterozygotes (69/180; 38.3%) or UGT1A1∗1 wild type (59/177; 33.3%). There was one treatment-related death due to an AE of aspiration pneumonia. Partial responses were seen in endometrial cancer (4/18, 22.2% ORR) and small-cell lung cancer (11/62, 17.7% ORR), and one castrate-resistant prostate cancer patient had a complete response (n = 1/11; 9.1% ORR).

CONCLUSIONS

SG demonstrated a toxicity profile consistent with previous published reports. Efficacy was seen in several cancer cohorts, which validates Trop-2 as a broad target in solid tumors.

Sacituzumab govitecan in previously treated hormone receptor-positive/HER2-negative metastatic breast cancer: final results from a phase I/II, single-arm, basket trial

BACKGROUND

Trophoblast cell-surface antigen-2 (Trop-2) is expressed in epithelial cancers, including hormone receptor-positive (HR+) metastatic breast cancer (mBC). Sacituzumab govitecan (SG; Trodelvy®) is an antibody-drug conjugate composed of a humanized anti-Trop-2 monoclonal antibody coupled to SN-38 at a high drug-to-antibody ratio via a unique hydrolyzable linker that delivers SN-38 intracellularly and in the tumor microenvironment. SG was granted accelerated FDA approval for metastatic triple-negative BC treatment in April 2020.

PATIENTS AND METHODS

We analyzed a prespecified subpopulation of patients with HR+/human epidermal growth factor receptor 2-negative (HER2-) HR+/HER2- mBC from the phase I/II, single-arm trial (NCT01631552), who received intravenous SG (10 mg/kg) and whose disease progressed on endocrine-based therapy and at least one prior chemotherapy for mBC. End points included objective response rate (ORR; RECIST version 1.1) assessed locally, duration of response (DOR), clinical benefit rate, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Fifty-four women were enrolled between 13 February 2015 and 1 June 2017. Median (range) age was 54 (33-79) years and all received at least two prior lines of therapy for mBC. At data cut-off (1 March 2019), 12 patients were still alive. Key grade ≥3 treatment-related toxicities included neutropenia (50.0%), anemia (11.1%), and diarrhea (7.4%). Two patients discontinued treatment due to treatment-related adverse events. No treatment-related deaths occurred. At a median follow-up of 11.5 months, the ORR was 31.5% [95% confidence interval (CI), 19.5%-45.6%; 17 partial responses]; median DOR was 8.7 months (95% CI 3.7-12.7), median PFS was 5.5 months (95% CI 3.6-7.6), and median OS was 12 months (95% CI 9.0-18.2).

CONCLUSIONS

SG shows encouraging activity in patients with pretreated HR+/HER2- mBC and a predictable, manageable safety profile. Further evaluation in a randomized phase III trial (TROPiCS-02) is ongoing (NCT03901339).

TRIAL REGISTRATION

ClinicalTrials.gov NCT01631552; https://clinicaltrials.gov/ct2/show/NCT01631552.

Sacituzumab govitecan (SG) in patients (pts) with previously treated metastatic endometrial cancer (mEC): results from a phase I/II study

6081

Background: Unselected pts with EC who progressed on prior chemotherapy have a poor prognosis with limited treatment options. SG is a novel antibody-drug conjugate that targets Trop-2, a cell surface glycoprotein highly expressed in many epithelial tumors. It is conjugated to deliver SN-38, the active metabolite of irinotecan, via a proprietary hydrolyzable linker. Preclinical studies show SG has activity against chemotherapy-resistant EC and significant bystander effect against EC with heterogenous Trop-2 expression (Perrone E. Mol Oncol. 2019). Methods: The phase I/II basket study (NCT01631552) evaluated pts unselected for Trop-2 with advanced solid tumors who received intravenous SG (days 1 and 8 of 21-day cycles), until progression or unacceptable toxicity. CT/MRI scans were obtained at 8-week intervals for response assessment by RECIST 1.1. We report results for mEC pts who progressed after ≥1 prior systemic therapy and were treated with SG 10 mg/kg. Endpoints include safety, objective response rate (ORR), clinical benefit rate (CBR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Results: 18 mEC pts (all women; 17 white and 1 black; median age 69 years [range, 41–76]) had a median 3.5 (range 2–6) prior lines of therapy. All pts received prior treatment with platinum therapies. At a median follow-up of 12.7 months, the ORR (95% CI) was 22.2% (6.4–47.6), with 4 partial responses. CBR (95% CI) was 44.4% (21.5–69.2), with 8 of 18 pts having either an objective response or stable disease ≥6 months. The DOR of responders ranged from 9.1 to 26.6 months, with 2 of 4 responders having a duration of ≥18 months. Median PFS (95% CI) was 3.2 months (1.9–9.4), and median OS (95% CI) was 11.9 months (4.7–not calculable). Key grade ≥3 TRAEs in the overall basket study safety population (n=495) included neutropenia (28%), neutrophil count decrease (14%), anemia (10%), diarrhea (8%), fatigue (6%), and febrile neutropenia (5%). A similar safety profile was seen in the mEC cohort. Conclusions: Median OS in unselected pts with mEC who progressed on prior platinum therapy is ~10 months with an ORR of ~10%. SG monotherapy showed clinical activity in pts with relapsed/refractory mEC, consistent with previous preclinical findings, and support further clinical investigation (NCT04251416). The phase II TROPiCS-03 (NCT03964727) study in pts with metastatic solid tumors selected based on elevated Trop-2 expression by a validated IHC assay will also provide further insights. Clinical trial information: NCT01631552.

TROPiCS–03: A phase II open-label study of sacituzumab govitecan (SG) in patients with metastatic solid tumors

TPS3648

Background: Trophoblast cell surface antigen (Trop-2) is highly expressed in many epithelial cancers (non–small-cell lung cancer [NSCLC], endometrial cancer, urothelial carcinoma [UC], and triple-negative breast cancer [TNBC]) and has been linked to aggressive disease and poor prognosis. SG is a Trop-2–directed antibody drug conjugate containing SN-38 (active metabolite of irinotecan) with a 7.5:1 drug-to-antibody ratio and unique hydrolyzable linker that allows for extracellular bystander effect. The phase 1/2 IMMU-132-01 basket study reported clinical activity with SG in patients with multiple tumor types not selected for Trop-2 expression including NSCLC (objective response rate [ORR]: 17%), TNBC (ORR: 33%), and UC (ORR: 31%).1-3 Results from the overall safety population (N=420) from this study found that SG was tolerable, with a predictable and manageable safety profile, and low discontinuation rates due to AEs. Methods: To test a biomarker-enrichment strategy with Trop-2, the TROPiCS-03 (TROP-2 Investigations in Cancer with SG) study was initiated. TROPiCS-03 (NCT03964727) is a multi-cohort, open-label, phase 2 study in patients with metastatic solid tumors - presently NSCLC (adenocarcinoma and squamous cell carcinoma), head and neck squamous cell carcinoma, and endometrial cancer - selected based on elevated Trop-2 expression by a validated IHC assay. Patients receive SG (10 mg/kg IV, days 1 and 8 every 21 days) and continue treatment until lack of clinical benefit or unacceptable toxicity. The primary endpoint is objective response rate (local assessment) and additional endpoints include clinical benefit rate, duration of response, progression-free survival, and safety. Females or males ≥18 years old who are histologically documented to have locally advanced or metastatic (M1, stage 4) solid tumors of the above types are eligible. Patients must have ECOG 0 or 1 and adequate clinical laboratory results to be enrolled. All subjects will have progressed after prior platinum-based chemotherapy and programmed death-ligand 1 (PD-L1) or programmed cell death protein 1 (PD-1) directed therapy. Patients who have previously received topoisomerase I inhibitors and those with known active CNS metastases are excluded. Approximately 160 patients will be enrolled in the trial overall; enrollment in the NSCLC cohort is currently in progress. References: Heist RS et al. J Clin Oncol. 2017;35:2790-7, Bardia A et al., NEJM. 2019;380:741-51.,Tagawa ST et al., Oral presentation; ASCO-GU 2019, San Francisco, CA. Clinical trial information: NCT03964727 .

Early results of TROPHY-U-01 Cohort 2: Sacituzumab govitecan (SG) in platinum-ineligible patients (pts) with metastatic urothelial cancer (mUC) who progressed after prior checkpoint inhibitor (CPI) therapy

5027

Background: SG is an antibody-drug conjugate consisting of a humanized monoclonal anti–Trop-2 antibody coupled to the cytotoxic agent, SN-38, via a unique hydrolyzable linker. The epithelial cell surface antigen, Trop-2, demonstrates greater expression between UC vs normal tissue, and is a promising target. In a phase 1/2 basket study (IMMU-132-01), SG showed an overall response rate (ORR) of 31% and manageable toxicity in 45 pts with mUC who had a median of 2 (range 1–6) prior therapy lines (Tagawa 2019 ASCO GU). Recent interim results for cohort 1 of the TROPHY-U-01 study in 35 pts with mUC who progressed on platinum and CPI therapy demonstrated an ORR of 29% in pts with a median of 3 prior treatment lines (range 2–6) (Tagawa 2019 ESMO). The most common grade ≥3 treatment-related AE (TRAE) was neutropenia. Methods: TROPHY-U-01 (NCT03547973) is a global, open-label, phase 2 trial evaluating the antitumor activity of SG (10 mg/kg, days 1 and 8 of 21-day cycles) in pts with advanced UC with measurable disease and ECOG PS 0 or 1. Cohort 2 includes platinum-ineligible pts who progressed after CPI therapy in the first-line metastatic setting. The primary objective is ORR evaluated with RECISTv1.1 by central review. Secondary objectives include progression-free survival, overall survival, and duration of response. Results: 18 pts with baseline tumor assessment (50% male; median age 79 y [range 57–87], 67% visceral metastases; 28% liver metastases) received a median of 2 (range 1–5) prior therapies. At a median follow-up of 6 months, ORR was 28% (5/18) with 4 confirmed PRs, and 1 PR pending confirmation. The majority of pts (61% [11/18]) had target lesion reduction. The safety profile was consistent with prior reports. Key grade ≥3 TRAEs were neutropenia (39%), fatigue (33%), diarrhea (28%), leukopenia (22%), anemia (17%), and febrile neutropenia (11%). No events of interstitial lung disease, ocular toxicities, or grade > 2 neuropathy were reported. There were no treatment-related deaths. Conclusions: In cisplatin-ineligible pts, the ORR for currently approved first-line CPI treatments is ~23–29% (Balar 2017 Lancet; Vuky 2018 ASCO). These preliminary data with SG show a manageable safety profile with an encouraging ORR of 28% and support the development of SG in platinum-ineligible pts with mUC who have progressed after CPI therapy. Clinical trial information: NCT03547973 .

TROPHY-U-01: A phase II open-label study of sacituzumab govitecan (IMMU-132) in patients with advanced urothelial cancer after progression on platinum-based chemotherapy and/or anti-PD-1/PD-L1 checkpoint inhibitor therapy

TPS3153

Background: Patients (pts) with advanced urothelial cancer (UC) who progress after checkpoint inhibitor (CPI) therapy (following failure of or ineligibility for platinum-based chemotherapy) have limited options. Trop-2 is an epithelial cell surface antigen overexpressed in UC (Avellini. Oncotarget 2017). Sacituzumab govitecan (SG) is an antibody-drug conjugate that targets Trop-2 and delivers the active metabolite SN38 of the topoisomerase I inhibitor irinotecan to tumor cells (Starodub. Clin Cancer Res 2015). In a phase 1/2 trial, pts with advanced cancers received SG on days 1 and 8 of a 21-day cycle. In the UC cohort, 45 evaluable pts received SG 10 mg/kg with a median of 2 (range 1–6) prior therapies. Objective response rate (ORR) was 31%; median duration of response was 12.9 mo. Grade ≥3 adverse events in ≥5% of pts were neutropenia/neutrophil count decreased (38%), anemia (13%), hypophosphatemia (11%), diarrhea (9%), fatigue (9%), and febrile neutropenia (7%). Median progression-free survival (PFS) was 7.3 mo and overall survival (OS) 16.3 mo (Tagawa 2019 ASCO Genitourinary Cancers Symposium). These results warrant further investigation in a dedicated phase 2 trial. Methods: TROPHY-U-01 (NCT03547973) is a single-arm, global phase 2 trial evaluating the antitumor activity of SG (10 mg/kg on days 1 and 8 of a 21-day cycle) in 140 pts with advanced UC and measurable disease. Patients are also required to have an Eastern Cooperative Oncology Group Performance Status score of 0 or 1 and creatinine clearance ≥30 mL/min. The pivotal cohort (Cohort 1: progression after both platinum chemotherapy and CPI) will enroll 100 evaluable pts in a Simon 2-stage design with > 90% power accounting for dropouts to exclude the null hypothesis or ORR < 12%; an exploratory cohort (Cohort 2: 40 pts) includes platinum-ineligible pts who progress after prior CPI. The primary objective is ORR per RECIST 1.1, assessed by central review. Secondary objectives include response duration, PFS, and OS. Adverse events, pharmacokinetics, and tissue correlates will also be assessed. Enrollment began August 2018. Clinical trial information: NCT03547973.

TiO2 Nanowires/Poly(Methyl Methacrylate) Based Hybrid Photodetector: Improved Light Detection

Hybrid photodetector with a maximum external quantum efficiency of ~3.08% in the UV region at 370 nm, was fabricated by spin-coated poly(methyl methacrylate) (PMMA) polymer onto glancing angle deposited (GLAD) vertically aligned TiO2 nanowire (NW) arrays. The TiO2 NWs/PMMA detector shows excellent rectification and constant 1.3 times photo-responsivity in the reverse bias condition from -1 V to -10 V. The photodiode possesses a low ideality factor of 5.1 as compared to bared TiO2 NWs device of 7.1. The hybrid device produces sharp turn-on of -0.8 s and turn-off transient of -0.9 s respectively.

Risk assessment for anterior cruciate ligament injury

INTRODUCTION

Anterior cruciate ligament tears are one of the most frequent soft tissue injuries of the knee. A torn anterior cruciate ligament leaves the knee joint unstable and at risk for further damage to other soft tissues manifested as pain, dislocation, and osteoarthritis. A better understanding of the anatomical details of knee joints suffering anterior cruciate ligament tears is needed to understand and develop prediction models for anterior cruciate ligament injury and/or tear.

MATERIALS AND METHODS

Magnetic resonance images of 32 patients with anterior cruciate ligament tears and 40 patients with non-tears were evaluated from a physician group practice. Digital measurements of femoral condyle length, femoral notch width, anterior cruciate ligament width in the frontal and sagittal plane, and the anterior cruciate ligament length in the sagittal plane were taken in both groups to identify trends. Monte Carlo simulations were performed (n = 2000) to evaluate the relationship between notch width index and sagittal width and to establish functional relationships among the anatomical parameters for potential injury risk. Sensitivity analysis performed shows the risk of anterior cruciate ligament injury a function of force and notch width index.

RESULTS

Females have a significantly shorter anterior cruciate ligament when compared to that of males. The notch width index was also significantly different between torn and non-torn individuals. The NWI was not significantly different between genders (p value = 0.40).

CONCLUSIONS

Anterior cruciate ligament injury has been shown to be caused by the forces which act on the ligament. These forces can result from hyperextension of the tibia or the internal rotation of tibia. The anatomical parameters of the knee joint (i.e., notch width index, anterior cruciate ligament width and length) have no role in the cause of an injury.

Improved Photo-Detection Using Zigzag TiO2 Nanostructures as an Active Medium

Zigzag TiO2 nanostructures were fabricated using oblique angle deposition technique. The field emission gun-scanning electron microscope (FEG-SEM) image shows that the TiO2 zigzag nanostructures were ~500 nm in length. Averagely two times enhanced UV-Vis absorption was recorded for zigzag structure compared to perpendicular TiO2 nanowires. The main band transition was observed at ~3.4 eV. The zigzag TiO2 exhibited high turn on voltage (+11 V) than that of nanowire (+2 V) detector under dark which were reduced to +0.2 V and +1.0 V under white light illumination, respectively. A maximum ~6 fold photo-responsivity was observed for the zigzag TiO2 compared with nanowire device at + 1.0 V applied potential. The maximum photo-responsivity of 0.36 A/W at 370 nm was measured for the zigzag TiO2 detector. The TiO2 zigzag detector showed slow response with rise time of 10.2 s and fall time of 10.3 s respectively. The UV (370 nm) to visible (450 nm) wavelength rejection ratio of photo-responsivity was recorded ~4 times for the detector.

Abstract CT230: Pediatric phase 1 trial of moxetumomab pasudotox: Activity in chemotherapy refractory acute lymphoblastic leukemia (ALL)

Background: Novel therapies are needed to overcome chemotherapy resistance and reduce toxicities of treatment for childhood ALL. CD22 is an antigen expressed on B-lineage ALL blasts. Moxetumomab pasudotox (MP) is a recombinant immunoconjugate composed of an anti-CD22 immunoglobulin variable domain genetically fused to a truncated form of Pseudomonas exotoxin.

Methods: This is a multicenter, open-label, phase 1, dose-escalation study of MP in pediatric patients (pts) with relapsed/refractory ALL and NHL with CD22 expression. MP is administered as a 30-min IV infusion at doses 5-50 µg/kg every other day for 6-10 doses every 21 days. Cohort A (n=7) consisted of an accelerated dose-escalation phase followed by standard 3+3 dose-escalation. To reduce the incidence of capillary leak syndrome (CLS), subsequent cohorts (B, n=23; C, n=14) received dexamethasone (2.5 mg/m2 every 12 hours) around the first 6 doses of MP in cycle 1. In Cohort C, doses were increased to 10/cycle and an expansion phase at 50 µg/kg was added.

Results: 44 pts with ALL 1-23 years of age have been treated. 35/44 had treatment-refractory disease; 20/44 had relapsed after stem cell transplant (SCT). Pts received a median of 1 treatment cycle (range 1-4). The majority (55%) of treatment-related adverse events (AEs) were mild and reversible. The most common treatment-related AEs were increased AST and ALT and weight gain. There were 2 treatment-related deaths and 7 pts discontinued therapy due to a treatment-related AE. Four DLTs included CLS in 2/7 pts in Cohort A (30 µg/kg; 1 reported as pleural effusion); hypercalcemia in 1 pt treated at 40 µg/kg (Cohort B) who died of a cardiac arrhythmia during attempted venous catheter placement; and grade 4 hemolytic uremic syndrome (HUS) in 1 pt at 50 µg/kg (Cohort B). HUS was noted in 6 pts, 5 treated at the 50 µg/kg dose. Two events were grade 4 with remaining cases ≤grade 2. All but 1 patient recovered from HUS. Based on HUS, the 50 µg/kg dose was determined to exceed the maximum tolerated dose and accrual at a lower dose is ongoing. Of the 37 (84%) pts evaluable for response, objective responses were achieved in 11 (30%), including 9 (24%) complete responses (CR). Per investigator report, 4/9 CRs were minimal residual disease negative, and 3 of these pts underwent a second SCT. Hematological activity (≥50% reduction in blasts and/or improvement in neutrophil and/or platelet counts) was observed in 11 (30%) pts. Anti-drug neutralizing antibodies (≥50% neutralization) developed in 7/44 (16%) pts.

Conclusions: MP is active in pediatric pts with relapsed/refractory ALL. The observed antileukemic activity and safety profile warrant further investigation; phase 2 trials are in development. Study sponsored by MedImmune, and supported in part by the Intramural Research Program of the NIH, NCI, CCR. ClinicalTrials.gov NCT00659425.

Citation Format: Alan S. Wayne, Nirali N. Shah, Deepa Bhojwani, Lewis B. Silverman, James A. Whitlock, Maryalice Stetler-Stevenson, Robert J. Kreitman, Trishna Goswami, Ramy Ibrahim, Ira Pastan. Pediatric phase 1 trial of moxetumomab pasudotox: Activity in chemotherapy refractory acute lymphoblastic leukemia (ALL). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT230. doi:10.1158/1538-7445.AM2014-CT230

TiO2 embedded Si nanowire network based Schottky detector for enlarged light detection

The Si nanowire (NW) network was fabricated on the Si substrate with the help of glancing angle synthesized Ag NPs assisted etching technique. The horizontal Si NWs network was characterized by field emission gun-scanning electron microscopy which shows the formation of long Si NWs of diameter within the range of 110-180 nm. The TiO2 thin film (TF) was deposited on the Si NWs, which shows -2.5 times enlarged optical absorption than that of bare Si substrate. Ag-TiO2 contacts exhibit Schottky behaviour and higher photoconduction was observed for TiO2-Si NW detector than that of TiO2 TF under illumination. The dark currents of TiO2 TF and TiO2-Si NW devices were exerted to be 0.1 mA/cm2 and 0.2 mA/cm2 at +1 V, which increased to 0.2 mA/cm2 and 1.23 mA/cm2, respectively, under the illumination of 100 W filament bulb. A threefold enhanced photodetection for the Si NW device was observed compared to the TiO2 TF device. The nonlinear rise of photocurrent of 2 x 10(-2) mA/cm2, after 5 min light illumination was observed due to carrier diffusion effect.

MEDI-551, an anti-CD19 antibody active in chronic lymphocytic leukemia (CLL) patients previously treated with rituximab

7045

Background: Anti-CD20 mAb therapy has provided survival advantage to patients (pts) with CLL; but pts invariably relapse after anti-CD20 therapy and new approaches are needed. The CLL cells of most pts express CD19, which are upregulated following anti-CD20 therapy. MEDI-551, an affinity-optimized anti-CD19 antibody, destroys malignant cells by Ab-dependent cellular cytotoxicity (ADCC) once bound to CD19. Methods: The activity and toxicity of single-agent MEDI-551 in CLL pts with prior rituximab administration was assessed in a phase 1/2, open-label, dose-escalation and expansion study (NCT00983619). Response was assessed using the 2008 Intl Working Group criteria. B-cell depletion was assessed with flow cytometry and confirmed with biomarker analyses (BAFF). Safety assessments included laboratory parameters and adverse events (AEs and serious AEs [SAEs]). Results: Of 91 pts with refractory B-cell malignancies included in the study, 26 had CLL. CLL pts had received a median of 6 prior therapies: 89% with chemotherapy, 27% with single-agent biologics. Within 3 cycles of MEDI-551 (3 mos), >60% of assessable pts achieved CD20+ B-cell depletion to <20 cell/uL. Decreases in circulating CD20+ and CD22+B cells were associated with concomitant increases in serum BAFF concentrations. Of 20 pts evaluable for response, 4 achieved partial response and 13 had stable disease. Commonly reported AEs were generally grade 1/2 and included infusion reactions (62%), nausea (23%), pyrexia (23%), and neutropenia (23%). Six SAEs were noted in 3 pts: 1 had infusion reaction and general health deterioration, another had subarachnoid hemorrhage (SAH), and a third had dyspnea, pyrexia, and back pain. Only infusion reaction was considered treatment related. Two treatment-unrelated events of general health deterioration and SAH resulted in death. Conclusions: Single-agent activity with a manageable toxicity profile was seen in CLL pts treated in this phase 1/2 study of MEDI-551. An ongoing phase 2 study of MEDI-551 in combination with bendamustine in relapsed CLL patients (NCT01466153) is evaluating clinical response to MEDI-551 and chemotherapy. This study was sponsored by MedImmune, LLC.

Phase I/II study of MEDI-551, a humanized monoclonal antibody targeting CD19, in subjects with relapsed or refractory advanced B-cell malignancies

8065

Background: Novel B-cell targeting agents, including monoclonal antibodies such as rituximab, are among recent advances in treatment of B-cell malignancies. New approaches are needed for patients progressing after rituximab-based therapies. MEDI-551 is an afucosylated monoclonal antibody targeting CD-19, a B-cell restricted transmembrane protein with enhanced affinity and antibody-dependent cellular cytotoxicity. Methods: Pts with relapsed or refractory follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia, or multiple myeloma received single agent MEDI-551 at dosages ranging from 0.5 mg/kg to 12 mg/kg via intravenous infusion over 28-day cycles; cohorts 1-6 received 0.5, 1, 2, 4, 8, and 12 mg/kg, respectively. Results: 25 pts were enrolled in the phase I portion Jun 2010–Aug 2011. No maximum tolerated dose (MTD) was achieved. Most AEs were grade 1/2 with dose-independent frequency and severity (Table). Six pts had grade 3 toxicities including tumor lysis syndrome, infusion reaction, thrombocytopenia, and neutropenia, or grade 4 neutropenia. No grade 5 AEs were seen. All pts recovered. Three partial responses (PR) and 2 complete responses (CR) were seen in DLBCL and FL pts at 0.5, 4, and 8 mg/kg. Activity included a CR lasting 9 mo. in a FL pt in cohort 1, who is currently being retreated with MEDI-551 on relapse. Conclusions: MEDI-551 demonstrated a safety profile warranting further study and showed no MTD reached at the highest dose studied. Anti-tumor activity is suggested by the responses achieved across dose levels. Phase II is currently enrolling subjects. This study is funded by MedImmune, LLC. [Table: see text]

Chirp and polarization control of femtosecond molecular fragmentation

We explore the simultaneous effect of chirp and polarization as the two control parameters for non-resonant photo-dissociation of n-propyl benzene. Experiments performed over a wide range of laser intensities show that these two control knobs behave mutually exclusively. Specifically, for the coherently enhanced fragments (C3H3+, C5H5+) with negatively chirped pulses and C6H5+ with positively chirped pulses, polarization effect is the same as compared to that in the case of transform-limited pulses. Though a change in polarization affects the overall fragmentation efficiency, the fragmentation pattern of n-propyl benzene molecule remains unaffected in contrast to the chirp case.

Optical biosensors: a revolution towards quantum nanoscale electronics device fabrication

The dimension of biomolecules is of few nanometers, so the biomolecular devices ought to be of that range so a better understanding about the performance of the electronic biomolecular devices can be obtained at nanoscale. Development of optical biomolecular device is a new move towards revolution of nano-bioelectronics. Optical biosensor is one of such nano-biomolecular devices that has a potential to pave a new dimension of research and device fabrication in the field of optical and biomedical fields. This paper is a very small report about optical biosensor and its development and importance in various fields.

The sarcoid-lymphoma syndrome

Whether a relationship exists between sarcoidosis and lymphoma is controversial. We present 4 patients diagnosed with sarcoidosis either during or after the treatment of lymphoma, review the data surrounding the entity known as "sarcoid-lymphoma syndrome" and discuss the diagnostic pitfalls it can present. As both entities are fluorine-18 fluorodeoxyglucose avid, histologic verification and clinical acumen are needed to avoid misdiagnosis before initiating therapy.

Novel molecular prognostic markers in breast cancer

BACKGROUND

Advances in the treatment of breast cancer have led to a reduction in breast-cancer-related mortality. However, these therapies are known to be associated with toxicities. Thus there is a crucial need to accurately define the populations of women with an excellent prognosis who may safely avoid the risks of systemic therapy. Recent developments utilizing novel technologies that incorporate our growing understanding of the biology and pathophysiology of breast cancer strive to better identify these patients.

OBJECTIVE

To provide a review of newer prognostic markers with a focus on the 21-gene recurrence score (Oncotype DX(™)), 70-gene prognosis profile (Mammaprint(®)), and Adjuvant! Online.

CONCLUSION

These techniques differ in their execution and application and have been demonstrated to provide further data on risk stratification as compared with conventional breast-cancer-risk factors.

A prospective multi-centre randomised controlled trial comparing PlasmaKnife with bipolar dissection tonsillectomy: evaluating an emerging technology

OBJECTIVE

To clinically evaluate and compare the PlasmaKnife to bipolar electrocautery in paediatric tonsillectomy.

METHODS

A prospective, multi-centred, double-blinded randomised controlled trial, conducted in central London teaching hospitals. The participants were 100 patients aged 2-16 years with recurrent tonsillitis or obstructive adenotonsillar hypertrophy awaiting a tonsillectomy were recruited in to the study. The primary outcome measures were throat, ear and swallowing pain scores over two weeks. Secondary outcome measures were return to normal diet, return to normal activity, analgesic requirements, operation time and intra-operative blood loss.

RESULTS

Surgical dissection was similar between the two groups with minimal blood loss and comparable overall operative times. We found that PlasmaKnife tonsillectomy caused more throat pain at 24 h (p=0.02). There was a tendency for a higher proportion in the bipolar dissection group to return to a normal diet, at day 3 (p=0.05) and at day 7 (p=0.04). The bipolar dissection returned to normal activities in a larger proportion than the PlasmaKnife group at day 3 (p=0.02) and at day 7 (p=0.01). There is some evidence of an association between use of analgesia at day 14 and method of tonsillectomy (p=0.03); the PlasmaKnife group tended to use less analgesia. During the study, four secondary bleeds occurred in the PlasmaKnife group and one in the bipolar dissection group, and all were managed conservatively.

CONCLUSION

Our study has found no significant advantage to PlasmaKnife over bipolar diathermy tonsillectomy. However, this preliminary study finds PlasmaKnife to be an interesting instrument and may warrant a larger randomised study to evaluate the potential advantages.

Death potentially secondary to sub-Tenon's block

An 82-year-old ASA 2 patient underwent routine sub-Tenon's block for cataract surgery. One minute after injection of the local anaesthetic, the patient had a generalised tonic-clonic seizure and developed refractory ventricular fibrillation; subsequent resuscitation was unsuccessful. With no evidence for intravascular injection, the lack of structural brain abnormalities, and the most striking feature on post mortem examination being severe triple vessel coronary artery disease, it was concluded that this was primarily cardiac in origin; however, the possibility of brainstem anaesthesia should also be considered.

Assessment of compressive modulus, hydraulic permeability and matrix content of trypsin-treated nucleus pulposus using quantitative MRI

A clinical strength MRI and intact bovine caudal intervertebral discs were used to test the hypotheses that (1) mechanical loading and trypsin treatment induce changes in NMR parameters, mechanical properties and biochemical contents; and (2) mechanical properties are quantitatively related to NMR parameters. MRI acquisitions, confined compression stress-relaxation experiments, and biochemical assays were applied to determine the NMR parameters (relaxation times T1 and T2, magnetization transfer ratio (MTR) and diffusion trace (TrD)), mechanical properties (compressive modulus H(A0) and hydraulic permeability k(0)), and biochemical contents (H(2)O, proteoglycan and total collagen) of nucleus pulposus tissue from bovine caudal discs subjected to one of two injections and one of two mechanical loading conditions. Significant correlations were found between k(0) and T1 (r=0.75,p=0.03), T2 (r=0.78, p=0.02), and TrD (r=0.85, p=0.007). A trend was found between H(A0) and TrD (r=0.56, p=0.12). However, loading decreased these correlations (r=0.4, p=0.2). The significant effect of trypsin treatment on mechanical properties, but not on NMR parameters, may suggest that mechanical properties are more sensitive to the structural changes induced by trypsin treatment. The significant effect of loading on T1 and T2, but not on H(A0) or k(0), may suggest that NMR parameters are more sensitive to the changes in water content enhanced by loading. We conclude that MRI offers promise as a sensitive and non-invasive technique for describing alterations in material properties of intervertebral disc nucleus, and our results demonstrate that the hydraulic permeability correlated more strongly to the quantitative NMR parameters than did the compressive modulus; however, more studies are necessary to more precisely characterize these relationships.

The Activity of Milk Leukocytes in Response to a Water-soluble Fraction of Mycobacterium phlei in Bovine Subclinical Mastitis

The effect of a water-soluble fraction (WSF) of a non-pathogenic strain of Mycobacterium phlei was studied in bovine subclinical mastitis (SCM) by measuring the myeloperoxidase and acid phosphatase enzyme levels in the milk leukocytes. Forty-five cows were divided into three equal groups. Group I, consisting of 15 healthy cows, served as the control, whereas groups II and III each contained 15 cows with subclinical mastitis on the basis of a positive reaction in the California mastitis test (CMT). The cows in group II received 100 microg of WSF in 5 ml sterile phosphate-buffered saline, pH 7.4 (PBS) once only, while those in group III received 5 ml sterile PBS daily for 7 days, both treatments being given by the intramammary route. Observations were made up to 30 days after treatment (AT). The CMT of the healthy milk was negative (0), whereas it ranged between 1 and 2 points in SCM. The somatic cell count (SCC) increased significantly (p < 0.05) on day 3, then fell steeply from day 7 up to day 30 AT in the cows in group II. A steady decrease in the total bacterial count (TBC) was observed in the group treated with WSF but the bacterial counts remained high in the groups treated with PBS. The mean acid phosphatase level was enhanced by 119% on day 3 AT in group II but only by 18.7% in the cows in group III. The mean myeloperoxidase level was enhanced by 100% in the cows in group II but only by 18% in those in group III on day 3 AT. This significant reduction in the bacterial load in infected cows caused by intramammary infusion of WSF may be due to activation of the microbicidal activity of the neutrophils, but this requires confirmation.

Elevated synthetic activity in the convex side of scoliotic intervertebral discs and endplates compared with normal tissues

STUDY DESIGN

We measured concentrations of specific molecules reflecting matrix synthesis and degradation in normal and scoliotic intervertebral discs and endplates.

OBJECTIVES

The aim of this work was to quantitate markers of matrix turnover in normal versus adolescent idiopathic scoliotic intervertebral discs and cartilaginous endplates.

SUMMARY OF BACKGROUND DATA

Changes in the intervertebral disc and endplate composition have been implicated as possible etiologic factors in the pathogenesis of adolescent idiopathic scoliosis. To better understand this process, it is important to compare the turnover of matrix components in scoliotic and normal intervertebral disc and endplate tissues. This comparison may help to improve our understanding of the role that disc and endplate tissues may play in the induction and/or progression of idiopathic scoliosis.

METHODS

Fifteen scoliotic and 17 normal intervertebral discs and endplates were analyzed for their water, collagen, proteoglycan, and protein content. In addition, newly synthesized aggrecan and collagen Types I and II were measured. Percent total denatured collagen was also determined.

RESULTS

The total collagen content was significantly lower in the scoliotic anulus and endplate regions, whereas glycosaminoglycan (GAG) content was significantly lower in the scoliotic endplates and nucleus regions. Conversely, total protein content was significantly higher in scoliotic endplates and elevated in scoliotic nucleus regions. Water content was significantly lower in the scoliotic anulus and endplate regions. When comparing the concave and convex regions of scoliotic endplates, there was no significant difference in concentration of any matrix component. The major difference in the synthetic marker levels relates to the synthesis of Type II collagen, which was higher in the nucleus, anulus, and endplate regions of scoliotic discs than in the corresponding regions of normal tissues. By contrast, the percent total denatured collagen was significantly elevated in the nucleus of normal tissues compared with the scoliotic ones.

CONCLUSIONS

The higher collagen Type II synthetic levels and increased total protein content with no matrix turnover suggest that scoliotic changes are due to an altered and ineffective synthetic response to a pathologic mechanical environment.

Natural-resistance-associated macrophage protein 1 is an H+/bivalent cation antiporter

In mammals, natural-resistance-associated macrophage protein 1 (Nramp1) regulates macrophage activation and is associated with infectious and autoimmune diseases. Nramp2 is associated with anaemia. Both belong to a highly conserved eukaryote/prokaryote protein family. We used Xenopus oocytes to demonstrate that, like Nramp2, Nramp1 is a bivalent cation (Fe2+, Zn2+ and Mn2+) transporter. Strikingly, however, where Nramp2 is a symporter of H+ and metal ions, Nramp1 is a highly pH-dependent antiporter that fluxes metal ions in either direction against a proton gradient. At pH 9.0, oocytes injected with cRNA from wild-type murine Nramp1 with a glycine residue at position 169 (Nramp1(G169); P=3.22x10(-6)) and human NRAMP1 (P=3.87x10(-5)) showed significantly enhanced uptake of radiolabelled Zn2+ compared with water-injected controls. At pH 5.5, Nramp1(G169) (P=1.34x10(-13)) and NRAMP1 (P=1.09x10(-6)) oocytes showed significant efflux of Zn2+. Zn2+ transport was abolished when the proton gradient was dissipated using carbonyl cyanide p-trifluoromethoxyphenylhydrazone. Using pre-acidified oocytes, currents of 130+/-57 nA were evoked by 100 microM Zn2+ at pH 7.5, and 139+/-47 nA by 100 microM Fe2+ at pH 7.0, in Nramp1(G169) oocytes; currents of 254+/-49 nA and 242+/-26 nA were evoked, respectively, in NRAMP1 oocytes. Steady-state currents evoked by increasing concentrations of Zn2+ were saturable, with apparent affinity constants of approx. 614 nM for Nramp1(G169) and approx. 562 nM for NRAMP1 oocytes, and a curvilinear voltage dependence of transporter activity (i.e. the data points approximate to a curve that approaches a linear asymptote). In the present study we propose a new model for metal ion homoeostasis in macrophages. Under normal physiological conditions, Nramp2, localized to early endosomal membranes, delivers extracellularly acquired bivalent cations into the cytosol. Nramp1, localized to late endosomal/lysosomal membranes, delivers bivalent cations from the cytosol into this acidic compartment where they may directly affect antimicrobial activity.

Understanding the multiple functions of Nramp1

Nramp1 regulates macrophage activation in infectious and autoimmune diseases. Nramp2 controls anaemia. Both are divalent cation (Fe(2+), Zn(2+), and Mn(2+)) transporters; Nramp2 a symporter of H(+) and metal ions, Nramp1 a H(+)/divalent cation antiporter. This provides a model for metal ion homeostasis in macrophages. Nramp2, localised to early endosomes, delivers extracellularly acquired divalent cations into the cytosol. Nramp1, localised to late endosomes/lysosomes, delivers divalent cations from the cytosol to phagolysosomes. Here, Fe(2+) generates antimicrobial hydroxyl radicals via the Fenton reaction. Zn(2+) and Mn(2+) may also influence endosomal metalloprotease activity and phagolysosome fusion. The many cellular functions dependent on metal ions as cofactors may explain the multiple pleiotropic effects of Nramp1, and its complex roles in infectious and autoimmune disease.