Overall Survival with Adjuvant Pembrolizumab in Renal-Cell Carcinoma

BACKGROUND

Adjuvant pembrolizumab therapy after surgery for renal-cell carcinoma was approved on the basis of a significant improvement in disease-free survival in the KEYNOTE-564 trial. Whether the results regarding overall survival from the third prespecified interim analysis of the trial would also favor pembrolizumab was uncertain.

METHODS

In this phase 3, double-blind, placebo-controlled trial, we randomly assigned (in a 1:1 ratio) participants with clear-cell renal-cell carcinoma who had an increased risk of recurrence after surgery to receive pembrolizumab (at a dose of 200 mg) or placebo every 3 weeks for up to 17 cycles (approximately 1 year) or until recurrence, the occurrence of unacceptable toxic effects, or withdrawal of consent. A significant improvement in disease-free survival according to investigator assessment (the primary end point) was shown previously. Overall survival was the key secondary end point. Safety was a secondary end point.

RESULTS

A total of 496 participants were assigned to receive pembrolizumab and 498 to receive placebo. As of September 15, 2023, the median follow-up was 57.2 months. The disease-free survival benefit was consistent with that in previous analyses (hazard ratio for recurrence or death, 0.72; 95% confidence interval [CI], 0.59 to 0.87). A significant improvement in overall survival was observed with pembrolizumab as compared with placebo (hazard ratio for death, 0.62; 95% CI, 0.44 to 0.87; P = 0.005). The estimated overall survival at 48 months was 91.2% in the pembrolizumab group, as compared with 86.0% in the placebo group; the benefit was consistent across key subgroups. Pembrolizumab was associated with a higher incidence of serious adverse events of any cause (20.7%, vs. 11.5% with placebo) and of grade 3 or 4 adverse events related to pembrolizumab or placebo (18.6% vs. 1.2%). No deaths were attributed to pembrolizumab therapy.

CONCLUSIONS

Adjuvant pembrolizumab was associated with a significant and clinically meaningful improvement in overall survival, as compared with placebo, among participants with clear-cell renal-cell carcinoma at increased risk for recurrence after surgery. (Funded by Merck Sharp and Dohme, a subsidiary of Merck; KEYNOTE-564 ClinicalTrials.gov number, NCT03142334.).

Patient-Reported Outcomes in KEYNOTE-564: Adjuvant Pembrolizumab Versus Placebo for Renal Cell Carcinoma

BACKGROUND

In patients with renal cell carcinoma (RCC) enrolled in the phase III KEYNOTE-564 trial (NCT03142334), disease-free survival (DFS) following nephrectomy was prolonged with use of adjuvant pembrolizumab therapy versus placebo. Patient-reported outcomes (PROs) provide an important measure of health-related quality of life (HRQoL) and can complement efficacy and safety results.

PATIENTS AND METHODS

In KEYNOTE-564, 994 patients were randomly assigned to receive pembrolizumab 200 mg (n = 496) or placebo (n = 498) intravenously every 3 weeks for ≤17 cycles. Patients who received ≥1 dose of treatment and completed ≥1 HRQoL assessment were included in this analysis. HRQoL end points were assessed using the EORTC QLQ-C30, FKSI-DRS, and EQ VAS. Prespecified and exploratory PRO end points were mean change from baseline in EORTC QLQ-C30 GHS/QoL score, EORTC QLQ-C30 physical function subscale score, and FKSI-DRS score.

RESULTS

No clinically meaningful difference in least squares mean scores for pembrolizumab versus placebo were observed at week 52 for EORTC QLQ-C30 GHS/QoL (-2.5; 95% CI -5.2 to 0.1), EORTC QLQ-C30 physical functioning (-0.87; 95% CI -2.7 to 1.0), and FKSI-DRS (-0.7; 95% CI -1.2 to -0.1). Most PRO scores remained stable or improved for the EORTC QLQ-C30 GHS/QoL (pembrolizumab, 54.3%; placebo, 67.5%), EORTC QLQ-C30 physical functioning (pembrolizumab, 64.7%; placebo, 68.8%), and FKSI-DRS (pembrolizumab, 58.2%; placebo, 66.3%).

CONCLUSIONS

Adjuvant treatment with pembrolizumab did not result in deterioration of HRQoL. These findings together with the safety and efficacy findings support adjuvant pembrolizumab treatment following nephrectomy.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03142334.

Adjuvant pembrolizumab (pembro) for renal cell carcinoma (RCC) across UCLA Integrated Staging System (UISS) risk groups and disease stage: Subgroup analyses from the KEYNOTE-564 study

679

Background: Adjuvant pembro prolonged disease-free survival (DFS) for patients (pts) with RCC at increased risk of recurrence after nephrectomy in the phase 3 KEYNOTE-564 study (NCT03142334). This post hoc exploratory analysis evaluated efficacy of adjuvant pembro in pt subgroups based on UISS and disease stage. Methods: Pts with histologically confirmed clear cell RCC (pT2, Grade [G] 4 or sarcomatoid, N0, M0; pT3 or pT4, any G, N0, M0; any pT, any G, N+, M0; or M1 NED) were randomly assigned 1:1 to receive pembro 200 mg IV or placebo (pbo) every 3 weeks for ≤17 cycles (~1 y). DFS was assessed by investigator. UISS risk groups were derived retrospectively from TNM stage, Fuhrman nuclear grade, and ECOG PS. UISS groups were intermediate risk (pT2, G4, N0, M0; pT3, G1, N0, M0; or pT3, G2-4, N0, M0, ECOG 0), high risk (pT3, G2-4, N0, M0, ECOG PS 1; pT4, any G, N0, M0; or N1, M0), or M1 NED. Other subgroups were evaluated based on disease stage. Results: Baseline characteristics were balanced within subgroups. Median follow-up was 30.1 mo (range 20.8-47.5). Of 994 enrolled pts, most had UISS intermediate risk (n = 732, 73.6%; pembro n = 359; pbo n = 373); 195 pts (19.6%; pembro n = 100; pbo n = 95) had UISS high risk, and 58 pts (5.8%; pembro and pbo n = 29 each) had M1 NED. In the UISS intermediate risk group, the hazard ratio (HR) for DFS was 0.65 (95% CI, 0.48-0.88; 24-mo rates, pembro: 81.5%, pbo: 72.4%). In the UISS high-risk group, HR for DFS was 0.77 (95% CI, 0.49-1.20; 24-mo rates, pembro: 65.0%, pbo: 55.9%). In the M1 NED group, HR for DFS was 0.28 (95% CI, 0.12-0.66; 24-mo rates, pembro: 78.4%, pbo: 37.9%). DFS by disease stage is in the Table. Conclusions: Consistent with the results of the intention-to-treat (ITT) population, adjuvant pembro prolonged DFS compared with pbo for all subgroups. Results of this exploratory analysis further support the use of adjuvant pembro after nephrectomy as standard of care for pts with RCC at increased risk of recurrence. Clinical trial information: NCT03142334 . [Table: see text]

Pembrolizumab versus placebo as post-nephrectomy adjuvant therapy for clear cell renal cell carcinoma (KEYNOTE-564): 30-month follow-up analysis of a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

The first interim analysis of the KEYNOTE-564 study showed improved disease-free survival with adjuvant pembrolizumab compared with placebo after surgery in patients with clear cell renal cell carcinoma at an increased risk of recurrence. The analysis reported here, with an additional 6 months of follow-up, was designed to assess longer-term efficacy and safety of pembrolizumab versus placebo, as well as additional secondary and exploratory endpoints.

METHODS

In the multicentre, randomised, double-blind, placebo-controlled, phase 3 KEYNOTE-564 trial, adults aged 18 years or older with clear cell renal cell carcinoma with an increased risk of recurrence were enrolled at 213 hospitals and cancer centres in North America, South America, Europe, Asia, and Australia. Eligible participants had an Eastern Cooperative Oncology Group performance status of 0 or 1, had undergone nephrectomy 12 weeks or less before randomisation, and had not received previous systemic therapy for advanced renal cell carcinoma. Participants were randomly assigned (1:1) via central permuted block randomisation (block size of four) to receive pembrolizumab 200 mg or placebo intravenously every 3 weeks for up to 17 cycles. Randomisation was stratified by metastatic disease status (M0 vs M1), and the M0 group was further stratified by ECOG performance status and geographical region. All participants and investigators involved in study treatment administration were masked to the treatment group assignment. The primary endpoint was disease-free survival by investigator assessment in the intention-to-treat population (all participants randomly assigned to a treatment). Safety was assessed in the safety population, comprising all participants who received at least one dose of pembrolizumab or placebo. As the primary endpoint was met at the first interim analysis, updated data are reported without p values. This study is ongoing, but no longer recruiting, and is registered with ClinicalTrials.gov, NCT03142334.

FINDINGS

Between June 30, 2017, and Sept 20, 2019, 994 participants were assigned to receive pembrolizumab (n=496) or placebo (n=498). Median follow-up, defined as the time from randomisation to data cutoff (June 14, 2021), was 30·1 months (IQR 25·7-36·7). Disease-free survival was better with pembrolizumab compared with placebo (HR 0·63 [95% CI 0·50-0·80]). Median disease-free survival was not reached in either group. The most common all-cause grade 3-4 adverse events were hypertension (in 14 [3%] of 496 participants) and increased alanine aminotransferase (in 11 [2%]) in the pembrolizumab group, and hypertension (in 13 [3%] of 498 participants) in the placebo group. Serious adverse events attributed to study treatment occurred in 59 (12%) participants in the pembrolizumab group and one (<1%) participant in the placebo group. No deaths were attributed to pembrolizumab.

INTERPRETATION

Updated results from KEYNOTE-564 support the use of adjuvant pembrolizumab monotherapy as a standard of care for participants with renal cell carcinoma with an increased risk of recurrence after nephrectomy.

FUNDING

Merck Sharp & Dohme LLC, a subsidiary of Merck & Co, Inc, Rahway, NJ, USA.

Adjuvant pembrolizumab for postnephrectomy renal cell carcinoma (RCC): Expanded efficacy analyses from KEYNOTE-564

4512

Background: The randomized, double-blind, phase 3 KEYNOTE-564 study (NCT03142334) met its primary end point of disease-free survival with adjuvant pembrolizumab versus placebo after nephrectomy in patients with localized RCC who are at increased risk for recurrence. Extended follow-up (30-month median follow-up) continued to support the benefit of adjuvant pembrolizumab. We describe additional efficacy analyses of time to first subsequent drug treatment or any-cause death (TFST) and time from randomization to progression on next line of therapy or any-cause death (PFS2). Methods: Patients with histologically confirmed clear cell RCC, with intermediate-high or high risk for recurrence (pT2, grade 4 or sarcomatoid, N0, M0; or pT3-4, any grade, N0 M0; or pT any stage, any grade, N+ M0) after nephrectomy, or after nephrectomy and resection of metastatic lesions (M1 NED), were randomly assigned 1:1 to receive pembrolizumab 200 mg IV or placebo Q3W for up to 17 cycles (̃1 y). Exploratory analyses of TFST and PFS2 were conducted. The Kaplan-Meier method was used to estimate TFST and PFS2. Hazard ratios (HRs) were estimated using a Cox regression model. Results: Of 994 patients, 496 were randomly assigned to receive pembrolizumab and 498 to placebo. Median time from randomization to the data cutoff date (June 14, 2021) was 30.1 months (range, 20.8-47.5). Overall, 67 patients (13.5%) in the pembrolizumab group and 99 patients (19.9%) in the placebo group received ≥1 line of subsequent anticancer drug therapy. Of patients who received ≥1 line of subsequent drug therapy, most in the pembrolizumab group (90.0% [60/67]) and placebo group (85.9% [85/99]) received a VEGF/VEGFR-targeted therapy; 23.9% of patients (16/67) in the pembrolizumab group and 59.6% (59/99) in the placebo group received an anti–PD-1/PD-L1 agent. Seventy-seven TFST events were observed in the pembrolizumab group; 110, in the placebo group. Compared with placebo, adjuvant treatment with pembrolizumab delayed TFST (HR, 0.67; 95% CI, 0.50-0.90; medians not reached). A total of 108 PFS2 events were observed, 40 (8.1%; 12 death events and 28 progression events) in the pembrolizumab group and 68 (13.7%; 14 death events and 54 progression events) in the placebo group. PFS2 was also delayed with pembrolizumab compared with placebo (HR, 0.57; 95% CI, 0.39-0.85; medians not reached). Conclusions: Treatment with adjuvant pembrolizumab reduced risk for TFST and PFS2 compared with placebo. Results of this exploratory analyses suggest sustained clinical benefit of adjuvant pembrolizumab and support the use of adjuvant pembrolizumab after nephrectomy as standard of care for patients with localized RCC at increased risk for recurrence. Clinical trial information: NCT03142334.

Efficacy and Safety of Autologous Dendritic Cell-Based Immunotherapy, Docetaxel, and Prednisone vs Placebo in Patients With Metastatic Castration-Resistant Prostate Cancer: The VIABLE Phase 3 Randomized Clinical Trial

IMPORTANCE

DCVAC/PCa is an active cellular immunotherapy designed to initiate an immune response against prostate cancer.

OBJECTIVE

To evaluate the efficacy and safety of DCVAC/PCa plus chemotherapy followed by DCVAC/PCa maintenance treatment in patients with metastatic castration-resistant prostate cancer (mCRPC).

DESIGN, SETTING, AND PARTICIPANTS

The VIABLE double-blind, parallel-group, placebo-controlled, phase 3 randomized clinical trial enrolled patients with mCRPC among 177 hospital clinics in the US and Europe between June 2014 and November 2017. Data analyses were performed from December 2019 to July 2020.

INTERVENTIONS

Eligible patients were randomized (2:1) to receive DCVAC/PCa (add-on and maintenance) or placebo, both in combination with chemotherapy (docetaxel plus prednisone). The stratification was applied according to geographical region (US or non-US), prior therapy (abiraterone, enzalutamide, or neither), and Eastern Cooperative Oncology Group performance status (0-1 or 2). DCVAC/PCa or placebo was administered subcutaneously every 3 to 4 weeks (up to 15 doses).

MAIN OUTCOMES AND MEASURES

The primary outcome was overall survival (OS), defined as the time from randomization until death due to any cause, in all randomized patients. Survival was compared using 2-sided log-rank test stratified by geographical region, prior therapy with abiraterone and/or enzalutamide, and Eastern Cooperative Oncology Group performance status.

RESULTS

A total of 1182 men with mCRPC (median [range] age, 68 [46-89] years) were randomized to receive DCVAC/PCa (n = 787) or placebo (n = 395). Of these, 610 (81.8%) started DCVAC/PCa, and 376 (98.4%) started placebo. There was no difference in OS between the DCVAC/PCa and placebo groups in all randomized patients (median OS, 23.9 months [95% CI, 21.6-25.3] vs 24.3 months [95% CI, 22.6-26.0]; hazard ratio, 1.04; 95% CI, 0.90-1.21; P = .60). No differences in the secondary efficacy end points (radiological progression-free survival, time to prostate-specific antigen progression, or skeletal-related events) were observed. Treatment-emergent adverse events related to DCVAC/PCa or placebo occurred in 69 of 749 (9.2%) and 48 of 379 (12.7%) patients, respectively. The most common treatment-emergent adverse events (DCVAC/PCa [n = 749] vs placebo [n = 379]) were fatigue (271 [36.2%] vs 152 [40.1%]), alopecia (222 [29.6%] vs 130 [34.3%]), and diarrhea (206 [27.5%] vs 117 [30.9%]).

CONCLUSIONS AND RELEVANCE

In this phase 3 randomized clinical trial, DCVAC/PCa combined with docetaxel plus prednisone and continued as maintenance treatment did not extend OS in patients with mCRPC and was well tolerated.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02111577.

Pembrolizumab as post nephrectomy adjuvant therapy for patients with renal cell carcinoma: Results from 30-month follow-up of KEYNOTE-564

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Background: The double-blind, multicenter, randomized KEYNOTE-564 study (NCT03142334) is the first positive phase 3 study of adjuvant immunotherapy for patients (pts) with renal cell carcinoma (RCC) at intermediate-high or high risk of recurrence after nephrectomy or nephrectomy and resection of metastatic lesions. Adjuvant pembrolizumab resulted in a statistically significant improvement in disease-free survival (DFS) vs placebo with 24 months of follow-up (HR 0.68, 95% CI 0.53−0.87; P = 0.0010 [one-sided]). We present updated efficacy and safety results from KEYNOTE-564 with 6 months of additional follow-up. Methods: Pts had histologically confirmed, clear cell RCC (pT2, grade 4 or sarcomatoid, N0 M0; pT3 or pT4, any grade, N0 M0; any pT, any grade, N+ M0; or M1 NED [no evidence of disease after primary tumor and soft tissue metastases completely resected ≤1 year from nephrectomy]) and had undergone surgery ≤12 weeks prior to randomization. The primary endpoint was DFS by investigator assessment in all randomized pts (ITT population). Overall survival (OS) was a key secondary endpoint. Safety/tolerability in all treated pts was a secondary endpoint. Results: 994 pts were randomized 1:1 to pembrolizumab (N = 496) or placebo (N = 498). As of data cutoff date of June 14, 2021, median (range) follow-up, defined as time from randomization to data cutoff, was 30.1 (20.8−47.5) months. In this updated analysis, DFS benefit with pembrolizumab was maintained (HR 0.63, 95% CI 0.50−0.80; nominal P < 0.0001) and was consistent across subgroups, including pts with M0 disease with intermediate-high risk of recurrence (HR 0.68, 95% CI 0.52−0.89), M0 high risk of recurrence (HR 0.60, 95% CI 0.33−1.10), or M1 NED (HR 0.28, 95% CI 0.12−0.66). The estimated DFS rate at 24 months was 78.3% with pembrolizumab vs 67.3% with placebo. A total of 66 OS events were observed, 23 in the pembrolizumab arm and 43 in the placebo arm (HR 0.52, 95% CI 0.31−0.86; P = 0.0048); the p-value did not cross the statistical hypothesis testing boundary and additional follow-up is planned for this key secondary endpoint. The estimated OS rate at 24 months was 96.2% with pembrolizumab vs 93.8% with placebo. With additional follow-up, no increase in any-grade or grade 3-4 adverse events, or steroid use for immune-mediated adverse events was observed. No deaths related to pembrolizumab occurred. Conclusions: At 30 months of follow-up, adjuvant pembrolizumab continued to demonstrate a consistent and clinically meaningful improvement in DFS vs placebo in pts with RCC at high risk of recurrence. No new safety signals were observed with pembrolizumab in the adjuvant setting. Clinical trial information: NCT03142334.

Administration of Nivolumab in Metastatic Renal Cell Cancer Following Treatment With mTOR Inhibitors

BACKGROUND/AIM

Immunotherapy with checkpoint inhibitors is currently considered a cornerstone of metastatic renal clear cell cancer (mRCC) therapy. Despite the general improvement in the survival of patients with mRCC, there are some clinical situations that have not been specifically evaluated in clinical trials, such as the use of everolimus before nivolumab.

PATIENTS AND METHODS

We performed a retrospective analysis evaluating the efficacy of nivolumab in the real-world setting, including a subset of patients with previous mTOR inhibitor therapy.

RESULTS

From a total of 56 patients, 25 were pre-treated with everolimus before receiving nivolumab. The overall progression-free survival (PFS), overall survival (OS), and objective response rate were 10.3, 21.3 months, and 34%, respectively. There were no statistically significant differences in patients who were or were not pre-treated with everolimus.

CONCLUSION

mRCC patients should be treated with checkpoint inhibitors and prior use of mTOR inhibitors should not be a definitive exclusion criterium.

Adjuvant Pembrolizumab after Nephrectomy in Renal-Cell Carcinoma

BACKGROUND

Patients with renal-cell carcinoma who undergo nephrectomy have no options for adjuvant therapy to reduce the risk of recurrence that have high levels of supporting evidence.

METHODS

In a double-blind, phase 3 trial, we randomly assigned, in a 1:1 ratio, patients with clear-cell renal-cell carcinoma who were at high risk for recurrence after nephrectomy, with or without metastasectomy, to receive either adjuvant pembrolizumab (at a dose of 200 mg) or placebo intravenously once every 3 weeks for up to 17 cycles (approximately 1 year). The primary end point was disease-free survival according to the investigator's assessment. Overall survival was a key secondary end point. Safety was a secondary end point.

RESULTS

A total of 496 patients were randomly assigned to receive pembrolizumab, and 498 to receive placebo. At the prespecified interim analysis, the median time from randomization to the data-cutoff date was 24.1 months. Pembrolizumab therapy was associated with significantly longer disease-free survival than placebo (disease-free survival at 24 months, 77.3% vs. 68.1%; hazard ratio for recurrence or death, 0.68; 95% confidence interval [CI], 0.53 to 0.87; P = 0.002 [two-sided]). The estimated percentage of patients who remained alive at 24 months was 96.6% in the pembrolizumab group and 93.5% in the placebo group (hazard ratio for death, 0.54; 95% CI, 0.30 to 0.96). Grade 3 or higher adverse events of any cause occurred in 32.4% of the patients who received pembrolizumab and in 17.7% of those who received placebo. No deaths related to pembrolizumab therapy occurred.

CONCLUSIONS

Pembrolizumab treatment led to a significant improvement in disease-free survival as compared with placebo after surgery among patients with kidney cancer who were at high risk for recurrence. (Funded by Merck Sharp and Dohme, a subsidiary of Merck; KEYNOTE-564 ClinicalTrials.gov number, NCT03142334.).

Pembrolizumab versus placebo as post-nephrectomy adjuvant therapy for patients with renal cell carcinoma: Randomized, double-blind, phase III KEYNOTE-564 study

LBA5

Background: Relapse after surgery for high-risk clear cell RCC (ccRCC) is associated with shortened life expectancy. Effective perioperative therapy to reduce this risk remains an unmet need. Adjuvant immune therapy is an attractive potential strategy for these pts. We conducted the KEYNOTE-564 trial to evaluate pembro vs placebo as adjuvant therapy for pts with RCC. Methods: KEYNOTE-564 is a phase III multicenter trial of pembro vs placebo in pts with histologically confirmed ccRCC, with intermediate-high risk (pT2, Gr 4 or sarcomatoid, N0 M0; or pT3, any Gr, N0 M0), high risk (pT4, any Gr, N0 M0; or pT any stage, any Gr, N+ M0), or M1 NED (no evidence of disease after primary tumor + soft tissue metastases completely resected ≤1 year from nephrectomy) (Leibovich et al, 2003; Fuhrman et al, 1982). Pts had undergone surgery ≤12 wks prior to randomization; had no prior systemic therapy; had ECOG PS 0 or 1. Study treatment was given for up to 17 cycles (≈1 yr). The primary endpoint was disease-free survival (DFS) per investigator assessment in all randomized pts (ITT population). Overall survival (OS) was a key secondary endpoint. Safety/tolerability were secondary endpoints, assessed in all treated pts. Results: Between Jun 30, 2017 and Sept 20, 2019, 994 pts were randomized 1:1 to pembro (n=496) or placebo (n=498). As of data cutoff date of Dec 14, 2020, median (range) follow-up, defined as time from randomization to data cutoff, was 24.1 (14.9−41.5) mo. No pts remain on study treatment. Baseline characteristics were generally balanced between arms. At first prespecified interim analysis, the primary endpoint of DFS was met (median not reached [NR] for both arms, HR 0.68, 95% CI 0.53−0.87; P=0.0010 [one-sided]). The estimated DFS rate at 24 mo was 77.3% with pembro vs 68.1% with placebo. Overall, DFS benefit was consistent across subgroups. A total of 51 OS events were observed (18 in the pembro arm, 33 in the placebo arm). Median OS was NR for both arms (HR 0.54, 95% CI 0.30−0.96; P=0.0164 [one-sided]); the p-value did not cross the statistical hypothesis testing boundary. The estimated OS rate at 24 mo was 96.6% with pembro vs 93.5% with placebo. 470 pts (96.3%) and 452 pts (91.1%) experienced ≥1 all-cause adverse events (AEs) with pembro vs placebo, respectively. Grade 3-5 all-cause AEs occurred in 158 pts (32.4%) with pembro and 88 pts (17.7%) with placebo. No deaths related to pembro occurred. Conclusions: Pembro demonstrated a statistically significant and clinically meaningful improvement in DFS vs placebo in pts with intermediate-high, high risk or M1 NED RCC. Additional follow-up is planned for the key secondary endpoint of OS. KEYNOTE-564 is the first positive phase III study with a checkpoint inhibitor in adjuvant RCC, and these results support pembro as a potential new standard of care for pts with RCC in the adjuvant setting. Clinical trial information: NCT03142334.

Metal-organic and covalent organic frameworks as single-site catalysts

Heterogeneous single-site catalysts consist of isolated, well-defined, active sites that are spatially separated in a given solid and, ideally, structurally identical. In this review, the potential of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) as platforms for the development of heterogeneous single-site catalysts is reviewed thoroughly. In the first part of this article, synthetic strategies and progress in the implementation of such sites in these two classes of materials are discussed. Because these solids are excellent playgrounds to allow a better understanding of catalytic functions, we highlight the most important recent advances in the modelling and spectroscopic characterization of single-site catalysts based on these materials. Finally, we discuss the potential of MOFs as materials in which several single-site catalytic functions can be combined within one framework along with their potential as powerful enzyme-mimicking materials. The review is wrapped up with our personal vision on future research directions.

Towards metal-organic framework based field effect chemical sensors: UiO-66-NH2 for nerve agent detection

Kelvin probe monitoring of metal-organic framework coated electrodes is demonstrated as a route for ppb-level detection of alkyl phosphonates.

We present a highly sensitive gas detection approach for the infamous ‘nerve agent’ group of alkyl phosphonate compounds. Signal transduction is achieved by monitoring the work function shift of metal–organic framework UiO-66-NH₂ coated electrodes upon exposure to ppb-level concentrations of a target simulant. Using the Kelvin probe technique, we demonstrate the potential of electrically insulating MOFs for integration in field effect devices such as ChemFETs: a three orders of magnitude improvement over previous work function-based detection of nerve agent simulants. Moreover, the signal is fully reversible both in dry and humid conditions, down to low ppb concentrations. Comprehensive investigation of the interactions that lead towards this high sensitivity points towards a series of confined interactions between the analyte and the pore interior of UiO-66-NH₂.

Travel-acquired infections in Canada: CanTravNet 2011-2012

BACKGROUND

Important gaps remain in our knowledge of the infectious diseases people acquire while travelling and the impact of pathogens imported by Canadian travellers.

OBJECTIVE

To provide a surveillance update of illness in a cohort of returned Canadian travellers and new immigrants.

METHODS

Data on returning Canadian travellers and new immigrants presenting to a CanTravNet site between September 2011 and September 2012 were extracted and analyzed by destination, presenting symptoms, common and emerging infectious diseases and disease severity.

RESULTS

During the study period, 2283 travellers and immigrants presented to a CanTravNet site, 88% (N=2004) of whom were assigned a travel-related diagnosis. Top three destinations for non-immigrant travellers were India (N=132), Mexico (N=103) and Cuba (N=89). Fifty-one cases of malaria were imported by ill returned travellers during the study period, 60% (N=30) of which were Plasmodium falciparum infections. Individuals travelling to visit friends and relatives accounted for 83% of enteric fever cases (15/18) and 41% of malaria cases (21/51). The requirement for inpatient management was over-represented among those with malaria compared to those without malaria (25% versus 2.8%; p<0.0001) and those travelling to visit friends and relatives versus those travelling for other reasons (12.1% versus 2.4%; p<0.0001). Nine new cases of HIV were diagnosed among the cohort, as well as one case of acute hepatitis B. Emerging infections among travellers included hepatitis E virus (N=6), chikungunya fever (N=4) and cutaneous leishmaniasis (N=16). Common chief complaints included gastrointestinal (N=804), dermatologic (N=440) and fever (N=287). Common specific causes of chief complaint of fever in the cohort were malaria (N=47/51 total cases), dengue fever (14/18 total cases), enteric fever (14/17 total cases) and influenza and influenza-like illness (15/21 total cases). Animal bites were the tenth most common diagnosis among tourist travellers.

INTERPRETATION

Our analysis of surveillance data on ill returned Canadian travellers provides a recent update to the spectrum of imported illness among travelling Canadians. Preventable travel-acquired illnesses and injuries in the cohort include malaria, enteric fever, HIV, hepatitis B, hepatitis A, influenza and animal bites. Strategies to improve uptake of preventive interventions such as malaria chemoprophylaxis, immunizations and arthropod/animal avoidance may be warranted.

Is there an intermediate-risk non-seminoma? long-term treatment results from a single center

PURPOSE

We retrospectively assessed the treatment results of patients with testicular non-seminoma to evaluate possible predictive and prognostic factors.

METHODS

189 patients with testicular non-seminoma treated between 2000 and 2012 were retrospectively evaluated. Treatment was based on orchiectomy plus chemotherapy (bleomycin/etoposide/cisplatin and vinblastine/ifosfamide/ cisplatin); retroperitoneal lymphadenectomy was only performed for residual disease after chemotherapy. The treatment protocol was updated regularly according to international standards. Overall survival (OS) was evaluated with the Kaplan-Meier method at a significance level of 5% according to stage, Karnofsky performance status (KPS), and chemotherapy dose intensity.

RESULTS

OS differed significantly for patients at different TNM stages (p=0.000); however, detailed analysis revealed significantly worse survival only in stage IIIC (10-year OS for IIIC vs IIIA+B, 35 vs 88%, p=0.001), while the difference between IIIB and lower stages was not significant (p=0.383). Patients with no chemotherapy dose reduction had significantly higher OS than those with any kind of dose reduction (10-year OS 96 vs 0%, p=0.000). For stage IIIC disease, however, dose intensity had no influence on OS (p=0.167). KPS had no prognostic significance for OS (KPS<80 vs ≥80, p=0.627) for stage IIIA+B and for stage IIIC.

CONCLUSION

The standard of care for testicular non-seminoma offers excellent prognosis with no significant differences in OS for good- and intermediate-risk patients. Reduction of chemotherapy dose negatively impacted OS in patients with stage IIIA+B and thus should be avoided.

Is there an intermediate risk group of nonseminoma?

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Background: To evaluate predictive factors of testicular nonseminoma cancer. Methods: Between 2000 and 2012, 189 patients with testicular nonseminoma cancer were evaluated. Stages according to TNM classification were I, II, and III for 84 patients (60%), 49 (26%), and 56 (30%). The median age of the patients was 31 years (range 18-77 years). Treatment was based on orchiectomy plus chemotherapy (bleomycine/etoposide/cisplatin and vinblastine/ifosfamide/cisplatin) and retroperitoneal lymphadenectomy in residual disease. Treatment protocol was updated regularly according to international standards. Overall survival (OS) was evaluated according to the stage, Karnofsky index (KI), and dose intensity of chemotherapy with the Kaplan-Meier method at 5% significance level. Results: There was a significant difference between OS in patient with the different stages (log-rank test, p=0.000), however, detailed analysis revealed that there is significantly worse survival in stage IIIC only (10-years OS for IIIC vs. IIIA+B, 35% vs. 88%, p=0.001) while the difference among IIIB and lower stages was not significant (p=0.383) and 10-years OS was 94%. Dose intensity of chemotherapy proved to be a significant predictive factor for OS in stage IIIA+B patients. Patients with no dose reduction had a significantly higher OS than those with any kind of dose reduction (10-years OS 96% vs. 0%, log-rank test, p=0,000). In stage IIIC, however, the dose intensity had no influence on OS (log-rank test, p=0.167). Unlike dose intensity, in stage III disease KI had no prognostic significance for OS (KI<80 versus KI≥80, Log-rank test, p=0,627) and this is true both for stages IIIA+B and for stage IIIC. Conclusions: Standard of care in testicular nonseminoma cancer offers excellent prognosis with no significant differences in OS for good and intermediate risk groups. On the other hand, outcomes for stage IIIC are poor and further intensification of treatment is warranted. We have found no impact of performance status on OS neither for stage IIIA+IIIB nor stage IIIC. Reduction of chemotherapy dose has a negative impact on OS in patients with stage IIIA+IIIB and should be avoided if possible.

Is the delay in diagnosis of pulmonary tuberculosis related to exposure to fluoroquinolones or any antibiotic?

BACKGROUND

Delays in diagnosis of tuberculosis (TB) have been associated with previous use of antibiotics, and in particular fluoroquinolones (FQ), for suspected pulmonary infections.

METHODS

We conducted a population-based cohort study with 2232 patients who had active TB between 1997 and 2006 (records obtained from the British Columbia Linked Health Databases). Patients with a record of an initial health care contact preceding the diagnosis of TB were identified for inclusion. Health care delay was defined as the time between initial health care contact and the initiation of anti-tuberculosis medication, and was compared between patients prescribed antibiotics and those not exposed to any antibiotics.

RESULTS

A total of 1544 patients were included. After adjusting for covariates, average health care delay for patients exposed to antibiotics was found to be significantly greater, by a factor of 2.10 (95%CI 1.80-2.44), with a median delay of 41 days in the antibiotic group compared to 14 days in the non-antibiotic group. Sex, age, foreign-born status and socio-economic status were non-significant factors. Health care delay increased with the number of antibiotic courses received, but not with the type of antibiotic.

CONCLUSIONS

Previous treatment with any antibiotic, and not only a FQ, is associated with a delay in TB diagnosis.

Developmental profile of serum nerve growth factor levels in Rett complex

Rett syndrome (RS) is a progressive neurodevelopmental disorder predominant in females, characterised by mental deficiency, stereotyped hand-washing and apraxia. Notwithstanding the recent identification of the MECP2 gene likely involved in the pathogenesis of SR, the neurobiological bases of this syndrome are still largely unknown. Converging evidence shows that the brain levels of nerve growth factor (NGF), a neurotrophin regulating the development and functioning of central cholinergic neurons, are decreased in RS girls. In this study, the serum levels of NGF were measured in classic RS, in the preserved speech variant (PSV) and in normal controls. Overall analysis failed to evidence significant differences among the three groups. However, whereas NGF levels increased significantly with age in controls, the opposite profile was observed in classic RS, with a progressive age-dependent decrease of NGF. In PSV subjects NGF levels remained constant with age. These findings strengthen the hypothesis of NGF involvement in the pathogenesis of RS.

[Salivary testosterone and cognitive ability in children]

There are suggestive data with indicate the link of testosterone levels with specific cognitive abilities in humans. As soon as during intrauterine development, testosterone is supposed to influence to organization of fetal specific brain structures. This influence is permanent and it is reflected in cognitive abilities during prepubetal period. In puberty, the testosterone level rapidly increases mainly in boys and it appears to influence the definitive development of cognitive functions. In this paper, results of the first four years of our logitudinal study are presented. Salivary testosterone levels in children were determined, and their effect on spatial ability was studied. Radioimmunoanalytical method of testosterone determination in saliva was developed, since saliva reflects free fraction of testosterone directly available for uptake by receptors in the central nervous system. The sampling of saliva is non-invasive and unstressful, which is important for relevant evaluation of cognitive performance. One hundred and forty-seven children (78 boys and 69 girls) at the ae of 8 to 12 were examined. The data received from intellectually gifted children attending the School for gifted children in Bratislava (100 measurements) were compared with the data received from age-matched children attending randomly chosen elementary schools (151 measurements). Lower salivary testosterone levels were found in intellectually gifted children of both sexes, and negative relationship between testosterone levels and cognitive abilities in preadolescent children was observed.

Alternate splicing produces a soluble form of the hereditary hemochromatosis protein HFE

HFE is a non-typical MHC class 1-type protein that is mutated in hereditary hemochromatosis. The purpose of this study was to identify possible splice variants of HFE mRNA and investigate the regulation of these isoforms in duodenum and liver of patients with normal and altered iron stores. RT-PCR was performed using HFE specific primers and duodenal RNA obtained from patients with hemochromatosis, iron deficiency, secondary iron overload and normal controls. The reaction products were visualized by Southern blot and identified by DNA sequence analysis. Additional studies were performed on RNA isolated from liver and a range of human tissues. A truncated (soluble) form of HFE protein was identified that lacks the transmembrane domain and occurs as a result of alternative splicing. Soluble HFE was found predominantly in the duodenum, spleen, breast, skin and testicle. In hereditary hemochromatosis full length HFE was the predominant isoform present in the duodenum similar to iron deficiency. Alternate splicing produces soluble HFE that may have a unique function to regulate cellular iron transport.

The value of student-made models as learning aids in physiology

In a new educational scheme introduced in Malta in 1978, university students spend half of the academic year studying and the other half as workers in various departments. During their work phase, students designed and made working models as teaching aids for the study of physiology. The value of these models was assessed on another group of students before they started their physiology course. These students completed a multiple choice questionnaire on three occasions: before and after having seen the models and after they had had them explained. In addition, they completed a questionnaire designed to elicit their views concerning these models. It was found that the models effectively improved knowledge with little staff involvement. The effectiveness of a model as an aid to learning was directly proportional to the degree of its appeal, but inversely proportional to its complexity in terms of stimulating factors. It is suggested that such models could help in teaching, compensating for shortage of staff, and that students' ability to produce teaching models should be wisely exploited.