[177Lu]Lu-PSMA-617 plus enzalutamide in patients with metastatic castration-resistant prostate cancer (ENZA-p): an open-label, multicentre, randomised, phase 2 trial

BACKGROUND

Enzalutamide and lutetium-177 [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 both improve overall survival in patients with metastatic castration-resistant prostate cancer. Androgen and PSMA receptors have a close intracellular relationship, with data suggesting complementary benefit if targeted concurrently. In this study, we assessed the activity and safety of enzalutamide plus adaptive-dosed [177Lu]Lu-PSMA-617 versus enzalutamide alone as first-line treatment for metastatic castration-resistant prostate cancer.

METHODS

ENZA-p was an open-label, randomised, controlled phase 2 trial done at 15 hospitals in Australia. Participants were men aged 18 years or older with metastatic castration-resistant prostate cancer not previously treated with docetaxel or androgen receptor pathway inhibitors for metastatic castration-resistant prostate cancer, gallium-68 [68Ga]Ga-PSMA-PET-CT (PSMA-PET-CT) positive disease, Eastern Cooperative Oncology Group performance status of 0-2, and at least two risk factors for early progression on enzalutamide. Participants were randomly assigned (1:1) by a centralised, web-based system using minimisation with a random component to stratify for study site, disease burden, use of early docetaxel, and previous treatment with abiraterone acetate. Patients were either given oral enzalutamide 160 mg daily alone or with adaptive-dosed (two or four doses) intravenous 7·5 GBq [177Lu]Lu-PSMA-617 every 6-8 weeks dependent on an interim PSMA-PET-CT (week 12). The primary endpoint was prostate-specific antigen (PSA) progression-free survival, defined as the interval from the date of randomisation to the date of first evidence of PSA progression, commencement of non-protocol anticancer therapy, or death. The analysis was done in the intention-to-treat population, using stratified Cox proportional hazards regression. This trial is registered with ClinicalTrials.gov, NCT04419402, and participant follow-up is ongoing.

FINDINGS

162 participants were randomly assigned between Aug 17, 2020, and July 26, 2022. 83 men were assigned to the enzalutamide plus [177Lu]Lu-PSMA-617 group, and 79 were assigned to the enzalutamide group. Median follow-up in this interim analysis was 20 months (IQR 18-21), with 32 (39%) of 83 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 16 (20%) of 79 patients in the enzalutamide group remaining on treatment at the data cutoff date. Median age was 71 years (IQR 64-76). Median PSA progression-free survival was 13·0 months (95% CI 11·0-17·0) in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 7·8 months (95% CI 4·3-11·0) in the enzalutamide group (hazard ratio 0·43, 95% CI 0·29-0·63, p<0·0001). The most common adverse events (all grades) were fatigue (61 [75%] of 81 patients), nausea (38 [47%]), and dry mouth (32 [40%]) in the enzalutamide plus [177Lu]Lu-PSMA-617 group and fatigue (55 [70%] of 79), nausea (21 [27%]), and constipation (18 [23%]) in the enzalutamide group. Grade 3-5 adverse events occurred in 32 (40%) of 81 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 32 (41%) of 79 patients in the enzalutamide group. Grade 3 events that occurred only in the enzalutamide plus [177Lu]Lu-PSMA-617 group included anaemia (three [4%] of 81 participants) and decreased platelet count (one [1%] participant). No grade 4 or 5 events were attributed to treatment on central review in either group.

INTERPRETATION

The addition of [177Lu]Lu-PSMA-617 to enzalutamide improved PSA progression-free survival providing evidence of enhanced anticancer activity in patients with metastatic castration-resistant prostate cancer with risk factors for early progression on enzalutamide and warrants further evaluation of the combination more broadly in metastatic prostate cancer.

FUNDING

Prostate Cancer Research Alliance (Movember and Australian Federal Government), St Vincent's Clinic Foundation, GenesisCare, Roy Morgan Research, and Endocyte (a Novartis company).

Overall survival with [177Lu]Lu-PSMA-617 versus cabazitaxel in metastatic castration-resistant prostate cancer (TheraP): secondary outcomes of a randomised, open-label, phase 2 trial

BACKGROUND

The TheraP study reported improved prostate-specific antigen responses with lutetium-177 [177Lu]Lu-PSMA-617 versus cabazitaxel in men with metastatic castration-resistant prostate cancer progressing after docetaxel. In this Article, we report the secondary outcome of overall survival with mature follow-up, and an updated imaging biomarker analysis. We also report the outcomes of participants excluded due to ineligibility on gallium-68 [68Ga]Ga-PSMA-11 and 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG) PET-CT.

METHODS

TheraP was an open-label, randomised phase 2 trial at 11 centres in Australia. Eligible participants had metastatic castration-resistant prostate cancer progressing after docetaxel, and PET imaging with [68Ga]Ga-PSMA-11 and 2-[18F]FDG that showed prostate-specific membrane antigen (PSMA)-positive disease and no sites of metastatic disease with discordant 2-[18F]FDG-positive and PSMA-negative findings. Participants were randomly assigned (1:1) to treatment with [177Lu]Lu-PSMA-617 (every 6 weeks for a maximum of six cycles; starting at 8·5 GBq, decreasing by 0.5 GBq to 6·0 GBq for the sixth cycle) versus cabazitaxel (20 mg/m2 every 3 weeks, maximum of ten cycles). Overall survival was analysed by intention-to-treat and summarised as restricted mean survival time (RMST) to account for non-proportional hazards, with a 36-month restriction time corresponding to median follow-up. This trial is registered with ClinicalTrials.gov, NCT03392428, and is complete.

FINDINGS

291 men were registered from Feb 6, 2018, to Sept 3, 2019; after study imaging, 200 were eligible and randomly assigned to treatment with [177Lu]Lu-PSMA-617 (n=99) or cabazitaxel (n=101). After completing study treatment, 20 (20%) participants assigned to cabazitaxel and 32 (32%) assigned to [177Lu]Lu-PSMA-617 were subsequently treated with the alternative regimen. After a median follow-up of 35·7 months (IQR 31·1 to 39·2), 77 (78%) participants had died in the [177Lu]Lu-PSMA-617 group and 70 (69%) participants had died in the cabazitaxel group. Overall survival was similar among those assigned to [177Lu]Lu-PSMA-617 versus those assigned to cabazitaxel (RMST 19·1 months [95% CI 16·9 to 21·4] vs 19·6 months [17·4 to 21·8]; difference -0·5 months [95% CI -3·7 to 2·7]; p=0·77). No additional safety signals were identified with the longer follow-up in this analysis. 80 (27%) of 291 men who were registered after initial eligibility screening were excluded after [68Ga]Ga-PSMA-11 and 2-[18F]FDG PET. In the 61 of these men with follow-up available, RMST was 11·0 months (95% CI 9·0 to 13·1).

INTERPRETATION

These results support the use of [177Lu]Lu-PSMA-617 as an alternative to cabazitaxel for PSMA-positive metastatic castration-resistant prostate cancer progressing after docetaxel. We did not find evidence that overall survival differed between the randomised groups. Median overall survival was shorter for men who were excluded because of low PSMA expression or 2-[18F]FDG-discordant disease.

FUNDING

Australian and New Zealand Urogenital and Prostate Cancer Trials Group, Prostate Cancer Foundation of Australia, Endocyte (a Novartis company), Australian Nuclear Science and Technology Organization, Movember, It's a Bloke Thing, CAN4CANCER, and The Distinguished Gentleman's Ride.

Biallelic SOX8 Variants Associated With Novel Syndrome With Myopathy, Skeletal Deformities, Intellectual Disability, and Ovarian Dysfunction

Background and Objectives

The human genome contains ∼20,000 genes, each of which has its own set of complex regulatory systems to govern precise expression in each developmental stage and cell type. Here, we report a female patient with congenital weakness, respiratory failure, skeletal dysplasia, contractures, short stature, intellectual delay, respiratory failure, and amenorrhea who presented to Medical Genetics service with no known cause for her condition.

Methods

Whole-exome and whole-genome sequencing were conducted, as well as investigational functional studies to assess the effect of SOX8 variant.

Results

The patient was found to have biallelic SOX8 variants (NM_014587.3:c.422+5G>C; c.583dup p.(His195ProfsTer11)). SOX8 is a transcriptional regulator, which is predicted to be imprinted (expressed from only one parental allele), but this has not yet been confirmed. We provide evidence that while SOX8 was maternally expressed in adult-derived fibroblasts and lymphoblasts, it was biallelically expressed in other cell types and therefore suggest that biallelic variants are associated with this recessive condition. Functionally, we showed that the paternal variant had the capacity to affect mRNA splicing while the maternal variant resulted in low levels of a truncated protein, which showed decreased binding at and altered expression of SOX8 targets.

Discussion

Our findings associate SOX8 variants with this novel condition, highlight how complex genome regulation can complicate novel disease-gene identification, and provide insight into the molecular pathogenesis of this disease.

The effect of Vitamin-K1 and Colchicine on Vascular Calcification Activity in subjects with Diabetes Mellitus (ViKCoVaC): A double-blind 2x2 factorial randomized controlled trial

BACKGROUND

There is currently no treatment for attenuating progression of arterial calcification. 18F-sodium fluoride positron emission tomography (18F-NaF PET) locates regions of calcification activity. We tested whether vitamin-K1 or colchicine affected arterial calcification activity.

METHODS

154 patients with diabetes mellitus and coronary calcification, as detected using computed tomography (CT), were randomized to one of four treatment groups (placebo/placebo, vitamin-K1 [10 mg/day]/placebo, colchicine [0.5 mg/day]/placebo, vitamin-K1 [10 mg/day]/ colchicine [0.5 mg/day]) in a double-blind, placebo-controlled 2x2 factorial trial of three months duration. Change in coronary calcification activity was estimated as a change in coronary maximum tissue-to-background ratio (TBRmax) on 18F-NaF PET.

RESULTS

149 subjects completed follow-up (vitamin-K1: placebo = 73:76 and colchicine: placebo = 73:76). Neither vitamin-K1 nor colchicine had a statistically significant effect on the coronary TBRmax compared with placebo (mean difference for treatment groups 0·00 ± 0·16 and 0·01 ± 0·17, respectively, p > 0.05). There were no serious adverse effects reported with colchicine or vitamin-K1.

CONCLUSIONS

In patients with type 2 diabetes, neither vitamin-K1 nor colchicine significantly decreases coronary calcification activity, as estimated by 18F-NaF PET, over a period of 3 months.

CLINICAL TRIAL REGISTRATION

ACTRN12616000024448.

Australasian Gastrointestinal Trials Group (AGITG) CONTROL NET Study: 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) and capecitabine plus temozolomide (CAPTEM) for pancreas and midgut neuroendocrine tumours (pNETS, mNETS)—Final results

4122

Background: CAPTEM is an accepted regimen for patients (pts) with advanced pNETs. Single agent PRRT is now a standard of care for progressive WHO Grade 1/2 mNETs. High activity was seen with PRRT/CAPTEM in a single arm Phase I/II trial. This study aims to determine the activity of combining CAPTEM with PRRT in mNETs and pNETs pts. Methods: Non-comparative randomised open label parallel group phase II trial with 2:1 randomisation to PRRT/CAPTEM (experimental arm) vs. PRRT (mNETs control) and CAPTEM (pNETS control). PRRT/CAPTEM: 7.8GBq 177Lu Octreotate (Lutate) given intravenously (IV) on day 10 every 8 weeks for 4 cycles, with concurrent oral capecitabine 750mg/m2 b.i.d. days 1-14 and temozolomide 75mg/m2 b.i.d. days 10-14 every 56 day cycle, up to 4 cycles. PRRT alone: 7.8GBq 177Lu Octreotate (Lutate) given intravenously (IV) on day 1 every 8 weeks for 4 cycles. CAPTEM alone: Oral capecitabine 750mg/m2 b.i.d. days 1-14 and days 29-42; Oral temozolomide 75mg/m2 b.i.d. days 10-14 and 38-42 every 56 day (8w) cycle. Primary endpoint: Progression free survival (PFS). mNETS: At 15 months, assuming PFS 66.4% in control arm; target PFS ³ 80%; pNETS: At 12 months, assuming PFS 60% in control arm; target PFS ³ 75%. Secondary endpoints: Objective tumor response rate (complete or partial) (OTRR), overall survival (OS), adverse events (AEs). Results: 75 pts enrolled (Dec 2015 – Nov 2018): mNETs 33 PRRT/CAPTEM, 14 PRRT, median follow up (mFU) 60.3 months; pNETS 19 PRRT/CAPTEM, 9 CAPTEM, mFU 57.5 months (mo). Late Grade 3/4 haematologic AEs: mNETS: 2/32 (6%) PRRT/CAPTEM pts and 4/13 (31%) PRRT pts. Events included myelodysplastic syndrome (40 mo), leukaemia (60 mo), pancytopenia (50 mo), anaemia (32 mo), thrombocytopenia (7 mo). No late haematologic G3/4 AEs were reported in the pNETS cohort. No late renal toxicity was identified in all study arms. Conclusions: CONTROL NETs is the first randomized trial to demonstrate efficacy for PRRT in pNETs, in addition to a standard of care. Extended follow up confirms durable CAPTEM/PRRT activity, with superior PFS in pNETs. Late haematologic toxicity was seen in both mNET PRRT arms but was not higher with additional CAPTEM. The activity of CAPTEM/PRRT in pNETs should be tested in the phase III setting. Clinical trial information: ACTRN12615000909527. [Table: see text]

99m Tc sestamibi SPECT/CT in the prediction of malignant versus benign small renal masses

OBJECTIVES

To determine the effectiveness of ^99m Tc-sestamibi renal SPECT/CT in distinguishing between malignant and benign renal lesions.

PATIENTS AND METHODS

Between June 2018 and October 2020 all patients with new indeterminate small renal masses (SRMs) underwent ^99m Tc-sestamibi renal SPECT/CT prior to biopsy or surgery. The accuracy of ^99m Tc-sestamibi imaging diagnoses was assessed against histopathology. Receiver operating characteristic (ROC) analysis was used to determine the optimum cut-off for the tumour:normal uptake ratio. Logistic regression was used to determine if quantitative analysis significantly added to visual interpretation alone.

RESULTS

A total of 74 patients with SRMs were investigated with ^99m Tc-sestamibi SPECT/CT. SPECT/CT correctly identified 49 malignant tumours and 11 benign tumours, resulting in a sensitivity of 0.89 [95% CI: 0.77 - 0.95] and a specificity of 0.73 [95% CI: 0.45 - 0.91]. ROC analysis of uptake ratios demonstrated that a tumour:normal uptake ratio of 0.41 provided optimal diagnostic accuracy (sensitivity 0.81, specificity 0.88, area under the curve 0.883 [95% CI:0.794 - 0.971]). The uptake ratio was also highly significant in excluding malignancy on univariate logistic regression analysis whereby the higher the uptake ratio, the lower the chances were for malignancy (OR 0.009,95% CI: 0.001-0.118, p < 0.001. However, this did not improve diagnostic accuracy when compared to visual interpretation alone.

CONCLUSION

^99m Tc-sestamibi SPECT/CT is a non-invasive technique with good accuracy in determining if a SRM is benign or malignant.

Long-term survival and toxicity in patients with progressive advanced neuroendocrine tumors treated with lutetium peptide radiolabelled radiotherapy: A Western Australian long-term follow-up study

e16202

Background: There are limited treatment options for advanced neuroendocrine tumours, and radiolabelled somatostatin analogues have shown favourable safety and efficacy over other existing treatments. Lutetium Octreotate has been shown to be the somatostatin analogue of choice in Peptide Radiolabelled Radiotherapy (PRRT) for advanced neuroendocrine tumours (NETs). Methods: We conducted a retrospective review of the long term safety and survival outcomes of 104 patients prospectively treated on the CLEMENT1, CLEMENT2, NETTLE, and NETT VALuE trials where patients with advanced progressive NETs were treated with Lutetium Octreotate PRRT in Perth, Western Australia. With a median follow-up time of 68 months, this is the longest follow-up study of advanced NETs treated with Lutetium PRRT in the literature to date. Results: Results showed comparable periods of disease stability as other studies, with median progression free survival of 43 months, and superior survival to other series, with a median survival of 71 months. There were patients who had very durable responses, with five year overall survival 61.5%, five year progression free survival 30.1%, 10 year overall survival 30.1%, and 10 year progression free survival of 29.3%, demonstrating Lu 177 can provide a very long duration of response in some patients. PRRT treatment was well tolerated with 1.9% of patients suffering long term renal impairment, and 1% with long term mild thrombocytopenia attributed to PRRT. Importantly, there was a higher rate of MDS and leukaemia in our series (6.7%), which is likely attributed to the longer period of follow-up with all except one case occurring 48 months after PRRT treatment, which is later than the median follow up in most other studies. Conclusions: Overall, this study showed that Lutetium PRRT remains an efficacious and well tolerated treatment in long term follow-up. For clinicians deciding on the timing of PRRT for individual patients the 6.7% long term risk of MDS/leukaemia needs to be balanced against the 29.3% PFS at 10 years. Clinical trial information: ACTRN12610000440022.

[177Lu]Lu-PSMA-617 versus cabazitaxel in patients with metastatic castration-resistant prostate cancer (TheraP): a randomised, open-label, phase 2 trial

BACKGROUND

Lutetium-177 [¹⁷⁷Lu]Lu-PSMA-617 is a radiolabelled small molecule that delivers β radiation to cells expressing prostate-specific membrane antigen (PSMA), with activity and safety in patients with metastatic castration-resistant prostate cancer. We aimed to compare [¹⁷⁷Lu]Lu-PSMA-617 with cabazitaxel in patients with metastatic castration-resistant prostate cancer.

METHODS

We did this multicentre, unblinded, randomised phase 2 trial at 11 centres in Australia. We recruited men with metastatic castration-resistant prostate cancer for whom cabazitaxel was considered the next appropriate standard treatment. Participants were required to have adequate renal, haematological, and liver function, and an Eastern Cooperative Oncology Group performance status of 0-2. Previous treatment with androgen receptor-directed therapy was allowed. Men underwent gallium-68 [⁶⁸Ga]Ga-PSMA-11 and 2-flourine-18[¹⁸F]fluoro-2-deoxy-D-glucose (FDG) PET-CT scans. PET eligibility criteria for the trial were PSMA-positive disease, and no sites of metastatic disease with discordant FDG-positive and PSMA-negative findings. Men were randomly assigned (1:1) to [¹⁷⁷Lu]Lu-PSMA-617 (6·0-8·5 GBq intravenously every 6 weeks for up to six cycles) or cabazitaxel (20 mg/m² intravenously every 3 weeks for up to ten cycles). The primary endpoint was prostate-specific antigen (PSA) response defined by a reduction of at least 50% from baseline. This trial is registered with ClinicalTrials.gov, NCT03392428.

FINDINGS

Between Feb 6, 2018, and Sept 3, 2019, we screened 291 men, of whom 200 were eligible on PET imaging. Study treatment was received by 98 (99%) of 99 men randomly assigned to [¹⁷⁷Lu]Lu-PSMA-617 versus 85 (84%) of 101 randomly assigned to cabazitaxel. PSA responses were more frequent among men in the [¹⁷⁷Lu]Lu-PSMA-617 group than in the cabazitaxel group (65 vs 37 PSA responses; 66% vs 37% by intention to treat; difference 29% (95% CI 16-42; p<0·0001; and 66% vs 44% by treatment received; difference 23% [9-37]; p=0·0016). Grade 3-4 adverse events occurred in 32 (33%) of 98 men in the [¹⁷⁷Lu]Lu-PSMA-617 group versus 45 (53%) of 85 men in the cabazitaxel group. No deaths were attributed to [¹⁷⁷Lu]Lu-PSMA-617.

INTERPRETATION

[¹⁷⁷Lu]Lu-PSMA-617 compared with cabazitaxel in men with metastatic castration-resistant prostate cancer led to a higher PSA response and fewer grade 3 or 4 adverse events. [¹⁷⁷Lu]Lu-PSMA-617 is a new effective class of therapy and a potential alternative to cabazitaxel.

FUNDING

Prostate Cancer Foundation of Australia, Endocyte (a Novartis company), Australian Nuclear Science and Technology Organization, Movember, The Distinguished Gentleman's Ride, It's a Bloke Thing, and CAN4CANCER.

Australian experience of peptide receptor radionuclide therapy in lung neuroendocrine tumours

Background: Peptide receptor radionuclide therapy (PRRT) is an approved treatment modality for gastroenteropancreatic neuroendocrine tumours (GEP NETs), Although Phase III randomised clinical trial data is not available for NETs of other site of origin, in practice, PRRT is used more widely in clinical practice, based on its mechanism of targeting the somatostatin receptor. Use of PRRT for lung (bronchial) NET, specifically typical and atypical carcinoid (TC, AC), has been reported only in small retrospective case series. This multicentre study adds to the evidence regarding utility of PRRT for lung NETs.

Materials and Methods: A retrospective chart review of patients with TC and AC who received ¹⁷⁷Lu-dotatate PRRT between January 2002 and June 2019 in six hospitals across Australia was undertaken. Data regarding demographics, efficacy and toxicity was evaluated at each site by the treating clinician.

Results: Forty-eight patients (32 AC, 15 TC, 1 unclassified) received a median of four ¹⁷⁷Lu-dotatate treatments. There was a median of one prior line of systemic treatment (range: 0–3). The response rate to ¹⁷⁷Lu-dotatate was 33%, with a median overall survival of 49 months (range of 3–91), at a median follow up of 33 months. This compares favourably with GEP NET. Overall toxicity was recorded as modest.

Conclusions: ¹⁷⁷Lu-dotatate PRRT in patients with lung NETs is used in real world practice, where it appears well-tolerated with some efficacy. Further evidence could be obtained through a global prospective clinical or registry trial.

Australasian Gastrointestinal Trials Group (AGITG) CONTROL NET Study: Phase II study evaluating the activity of 177Lu-Octreotate peptide receptor radionuclide therapy (LuTate PRRT) and capecitabine, temozolomide CAPTEM)—First results for pancreas and updated midgut neuroendocrine tumors (pNETS, mNETS)

4608

Background: CAPTEM is an accepted regimen for patients (pts) with advanced pNETs. Single agent 177Lu-Octreotate PRRT is now a standard of care for progressive WHO Grade (G) 1/2 mNETs. High activity was seen with LuTate/CAPTEM in a single arm Phase I/II trial. This study was undertaken to determine the relative activity of adding CAPTEM to LuTate PRRT in pts with mNETs and pNETs. Methods: Non-comparative randomised open label parallel group phase II trial with 2:1 randomisation to PRRT/CAPTEM (experimental arm) vs. PRRT (mNETs control) and CAPTEM (pNETS control). PRRT/CAPTEM: 7.8GBq LuTate day(D) 10, 8 weekly (wkly) x 4, with b.i.d. oral CAP 750mg/m2 D1-14 & TEM 75mg/m2D10-14, 8 wkly x 4; PRRT: 8 wkly x 4; CAPTEM 8 wkly x 4. Primary endpoint: Progression free survival (PFS). mNETS- at 15 months (mo) assuming 15mo PFS 66.4% in control arm, aiming for PFS ³ 80%; pNETS- at 12mo assuming 12mo PFS 60% in control arm, aiming for PFS ³ 75%. Secondary endpoints: Objective tumour response rate (complete or partial) (OTRR), clinical benefit rate (OTRR, stable disease) (CBR), toxicity, quality of life. Results: 75 pts enrolled (Dec 2015 – Nov 2018): mNETs 33 PRRT/CAPTEM and 14 PRRT; pNETS 19 PRRT/CAPTEM and 9 CAPTEM. mNETS: Median follow-up 35mo; 15mo PFS was 90% (95% CI: 73-97%) v 92% (95% CI: 57-99%); OTRR 31% vs 15%; and CBR 97% vs 92% for PRRT/CAPTEM v PRRT respectively. Treatment related adverse events (AEs): 24/32 PRRT/CAPTEM pts had at least one G3 event (75%) vs 5/13 (38%, PRRT); and 4/32 pts at least one G4 event (13%) v 1/13 (8%) respectively, mostly haematologic (haem). Only one patient failed to complete therapy (PRRT/CAPTEM). pNETS: Median follow-up 34mo; 12mo PFS was 76% (95% CI: 48-90%) v 67% (95% CI: 28-88%); OTRR 68% vs 33%; and CBR 100% vs 100% for PRRT/CAPTEM v CAPTEM respectively. Treatment related AEs: 5/18 PRRT/CAPTEM pts had at least one G3 event (28%) vs 3/9 (33%) CAPTEM; 3/18 pts at least one G4 event (17%) v 1/9 (11%) respectively. Conclusions: CAPTEM/PRRT is active, meeting its target landmark PFS for CAPTEM/PRRT (12mo pNETs; 15mo mNETs) with numerically greater OTRR in both pNETs and mNETs, but with more haem toxicity in mNETs. As activity was high in both control arms longer follow up is required to determine if the relative activity of PRRT/CAPTEM is sufficient to warrant Phase III evaluation. Clinical trial information: ACTRN12615000909527 .

First results for Australasian Gastrointestinal Trials Group (AGITG) control net study: Phase II study of 177Lu-octreotate peptide receptor radionuclide therapy (LuTate PRRT) +/- capecitabine, temozolomide (CAPTEM) for midgut neuroendocrine tumors (mNETs)

604

Background: Single agent 177Lu-octreotate peptide receptor radionuclide therapy is now a standard of care for progressive mNETS. High activity was seen with LuTate and concurrent CAPTEM chemotherapy in a single arm Phase I/II trial. This study was undertaken to determine the relative activity of adding CAPTEM to LuTate PRRT in patients with mNETs. Methods: Non-comparative randomised open label phase II trial of PRRT +/- CAPTEM in patients with mNETs, with 2:1 randomisation: PRRT /CAPTEM (experimental arm) vs. PRRT (control). PRRT /CAPTEM: 7.8GBq LuTate day(D) 10, 8 weekly (wkly) x 4, with b.i.d. oral CAP 750mg/m2 D1-14 & TEM 75mg/m2 D10-14, 8 wkly x 4, vs. PRRT 8 wkly x 4. Primary endpoint: progression free survival (PFS) at 15 months assuming 15 month PFS of 66.4% in the control arm, aiming for PFS rate > 80%; secondary endpoints: objective tumour response rate (complete or partial response) (OTRR), clinical benefit rate (complete or partial response, stable disease) (CBR), toxicity, and QOL. Results: 47 patients enrolled (Dec 2015 - Feb 2018): 33 PRRT/CAPTEM and 14 PRRT. Two patients withdrew prior to treatment. Patient characteristics were balanced except gender (female 58% vs. 14%). Two patients received 2 prior systemic regimens. After a median follow-up of 32 months, the 15 month PFS was 90% (95% CI: 73-97%) v 92% (95% CI: 57-99%); OTRR 25% vs 15%; and CBR 97% vs 92% for PRRT/CAPTEM v PRRT respectively. For treatment related adverse events 22/32 CAPTEM patients experienced one Grade 3 event (69%) vs 5/13 (38%, PRRT); 4/32 pts experienced one Grade 4 event (13%) v 1/13 (8%) respectively. Only one patient failed to complete therapy due to toxicity (PRRT/CAPTEM). Conclusions: This initial planned analysis demonstrates similarly high 15 month PFS for CAPTEM/PRRT relative to PRRT alone. OTRR is numerically higher but at the cost of greater toxicity. Longer follow up is required to determine if the activity of PRRT/CAPTEM is sufficient to warrant Phase III evaluation. Clinical trial information: ACTRN12615000909527.

Consensus-Derived Quality Performance Indicators for Neuroendocrine Tumour Care

Quality performance indicators (QPIs) are used to monitor the delivery of cancer care. Neuroendocrine tumours (NETs) are a family of individually uncommon cancers that derive from neuroendocrine cells or their precursors, and can occur in most organs. There are currently no QPIs available for NETs and their heterogeneity makes QPI development difficult. CommNETs is a collaboration between NET clinicians, researchers and advocates in Canada, Australia and New Zealand. We created QPIs for NETs using a three-step consensus process. First, a multidisciplinary team used the nominal group technique to create candidates (n = 133) which were then curated into appropriateness statements (62 statements, 44 sub-statements). A two-stage modified RAND/UCLA Delphi consensus process was conducted: an online survey rated the statement appropriateness then the top-ranked statements (n = 20) were assessed in a face-to-face meeting. Finally, 10 QPIs met consensus criteria; documentation of primary site, proliferative index, differentiation, tumour board review, use of a structured pathology report, presence of distant metastasis, 5- and 10-year disease-free and overall survival. These NET QPIs will be trialed as a method to monitor and improve care for people with NETs and to facilitate international comparison.

Impact of contusion injury on intramuscular emm1 group a streptococcus infection and lymphatic spread

Invasive group A Streptococcus (iGAS) is frequently associated with emm1 isolates, with an attendant mortality of around 20%. Cases occasionally arise in previously healthy individuals with a history of upper respiratory tract infection, soft tissue contusion, and no obvious portal of entry. Using a new murine model of contusion, we determined the impact of contusion on iGAS bacterial burden and phenotype.

Calibrated mild blunt contusion did not provide a focus for initiation or seeding of GAS that was detectable following systemic GAS bacteremia, but instead enhanced GAS migration to the local draining lymph node following GAS inoculation at the same time and site of contusion. Increased migration to lymph node was associated with emergence of mucoid bacteria, although was not specific to mucoid bacteria. In one study, mucoid colonies demonstrated a significant increase in capsular hyaluronan that was not linked to a covRS or rocA mutation, but to a deletion in the promoter of the capsule synthesis locus, hasABC, resulting in a strain with increased fitness for lymph node migration.

In summary, in the mild contusion model used, we could not detect seeding of muscle by GAS. Contusion promoted bacterial transit to the local lymph node. The consequences of contusion-associated bacterial lymphatic migration may vary depending on the pathogen and virulence traits selected.

Development and evaluation of a driving observation schedule (DOS) to study everyday driving performance of older drivers

This paper describes the development and evaluation of an on-road procedure, the Driving Observation Schedule (DOS), for monitoring individual driving behavior. DOS was developed for use in the Candrive/Ozcandrive five-year prospective study of older drivers. Key features included observations in drivers' own vehicles, in familiar environments chosen by the driver, with start/end points at their own homes. Participants were 33 drivers aged 75+ years, who drove their selected route with observations recorded during intersection negotiation, lane-changing, merging, low speed maneuvers and maneuver-free driving. Driving behaviors were scored by a specialist occupational therapy driving assessor and another trained observer. Drivers also completed a post-drive survey about the acceptability of DOS. Vehicle position, speed, distance and specific roadways traveled were recorded by an in-vehicle device installed in the participant's vehicle; this device was also used to monitor participants' driving over several months, allowing comparison of DOS trips with their everyday driving. Inter-rater reliability and DOS feasibility, acceptability and ecological validity are reported here. On average, drivers completed the DOS trip in 30.48min (SD=7.99). Inter-rater reliability measures indicated strong agreement between the trained and the expert observers: intra-class correlations (ICC)=0.905, CI 95% 0.747-0.965, p<0.0001; Pearson product correlation, r (18)=.83, p<0.05. Standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV) measures were consistently small (3.0, 2.9 & 3.3%, respectively). Most participants reported being 'completely at ease' (82%) with the driving task and 'highly familiar with the route' (97%). Vehicle data showed that DOS trips were similar to participants' everyday driving trips in roads used, roadway speed limits, drivers' average speed and speed limit compliance. In summary, preliminary findings suggest that DOS can be scored reliably, is of feasible duration, is acceptable to drivers and representative of everyday driving. Pending further research with a larger sample and other observers, DOS holds promise as a means of quantifying and monitoring changes in older drivers' performance in environments typical of their everyday driving.

Characterising neovascularisation in fracture healing with laser Doppler and micro-CT scanning

Vascularity of the soft tissues around a bone fracture is critical for successful healing, particularly when the vessels in the medullary canal are ruptured. The objective of this work was to use laser Doppler and micro-computer tomography (micro-CT) scanning to characterise neovascularisation of the soft tissues surrounding the fracture during healing. Thirty-two Sprague–Dawley rats underwent mid-shaft osteotomy of the left femur, stabilised with a custom-designed external fixator. Five animals were killed at each of 2, 4 days, 1, 2, 4 and 6 weeks post-operatively. Femoral blood perfusion in the fractured and intact contralateral limbs was measured using laser Doppler scanning pre- and post-operatively and throughout the healing period. At sacrifice, the common iliac artery was cannulated and infused with silicone contrast agent. Micro-CT scans of the femur and adjacent soft tissues revealed vessel characteristics and distribution in relation to the fracture zone. Blood perfusion dropped immediately after surgery and then recovered to greater than the pre-operative level by proliferation of small vessels around the fracture zone. Multi-modal imaging allowed both longitudinal functional and detailed structural analysis of the neovascularisation process.

Grunt language versus accent: the perceived communication barriers between international medical graduates and patients in Central Wheatbelt catchments

Due to the chronic shortages of GPs in Australian rural and remote regions, considerable numbers of international medical graduates (IMG) have been recruited. IMG experience many difficulties when relocating to Australia with one of the most significant being effective GP-patient communication. Given that this is essential for effective consultation it can have a substantial impact on health care. A purposive sample of seven practising GPs (five IMG, two Australian-trained doctors (ATD)) was interviewed using a semistructured face-to-face interviewing technique. GPs from Nigeria, Egypt, United Kingdom, India, Singapore and Australia participated. Interviews were transcribed and then coded. The authors used qualitative thematic analysis of interview transcripts to identify common themes. IMG-patient communication barriers were considered significant in the Wheatbelt region as identified by both IMG and ATD. ATD indicated they were aware of IMG-patient communication issues resulting in subsequent consults with patients to explain results and diagnoses. Significantly, a lack of communication between ATD and IMG also emerged, creating a further barrier to effective communication. Analysis of the data generated several important findings that rural GP networks should consider when integrating new IMG into the community. Addressing the challenges related to cross-cultural differences should be a priority, in order to enable effective communication. More open communication between ATD and IMG about GP-patient communication barriers and education programs around GP-patient communication would help both GP and patient satisfaction.

A proximal femoral implant preserves physiological bone deformation: a biomechanical investigation in cadaveric bones

The aim of this study was to compare the perturbances in bone deformation patterns of the proximal femur due to a conventional cemented femoral stem and a novel uncemented implant designed on the principles of osseointegration. Five matched pairs of fresh frozen human femora were mechanically tested. Bone deformation patterns, measured with a video digitizing system under 1.5 kN joint force, showed that the cemented Spectron femoral implant caused significant alterations to the proximal femoral deformation pattern, whereas the Gothenburg osseointegrated titanium femoral implant did not significantly alter the bone behaviour (p < 0.05). Vertical micromotions measured under 1 kN after 1000 cycles were within the threshold of movement tolerable for bone ingrowth (21 microm for the Gothenburg system and 26 microm for the cemented implant).

Fatigue testing of a proximal femoral hip component

The Gothenburg Osseointegrated Titanium (GOT) implant is a novel total hip replacement including a metaphyseal loading proximal femoral component fixed in the retained femoral neck. Endurance testing was performed under conditions analogous to ISO 7206-4: 1989. The cement-free implant is not fixed distally within the intramedullary canal, so distal embedding (as specified in the standard) would have been unrealistic. Instead glass-fibre-reinforced epoxy (GFRE) bushings were used to model reduced bone support mid-length at the medial cortex and distally at the lateral cortex. Such support simulated proximal bone loss, realistically reproducing the effect of osteolysis or fixation failure. Under such conditions the component survived unbroken for 10 million cycles at 3.0 kN peak load.

Friction in orthopaedic zirconia taper assemblies

The torque resistance of zirconia ceramic heads/titanium taper trunnion junctions was tested in accordance with ISO 7206-9:1994(E); using twelve modified heads of 32 mm diameter under representative physiological conditions. Test parameters studied included assembly force, vertical load during test (test load) and head length. Mean torque resistances measured were 8.9 N m for a 1 kN test load and 15 N m at 4 kN test load. Coefficients of friction calculated for the torsional stability ranged from 0.06 to greater than 1.0. Multiple regression analysis confirmed that the failure torques measured were significantly dependent on test load (beta = 0.77; P < 0.001) whereas assembly force and head length played a lesser, insignificant, part in the variation. Data from push-on/pull-off tests were used to calculate coefficients of friction under axial loading, which were significantly correlated with taper angle and material. Torque testing shows greater variability than push-on/pull-off tests for similar combinations, and for zirconia heads on other tapers. The coefficients of friction measured (0.16-0.31) are significantly different from values typically used in stress analyses.

Inaccuracy of acetabular reaming under surgical conditions

Press-fit uncemented acetabular components require accurate implant-bone cavity fit. Ten cavities produced during actual hip arthroplasty using debris-retaining reamers were replicated in dental alginate. An experimental reamer with better cutting prepared 12 acetabulae in mortuo under similar conditions. Positives in dental stone were measured on a coordinate measuring center. Spheres of best-fit and variation of each point from these spheres were calculated. Control cavities in polyurethane foam were measured to estimate casting errors. Diametral errors of conventionally reamed cavities averaged 2.1%, whereas experimental reamers' cavities varied by 0.5% (P < .005). Overall surface variation from hemispheric form in conventionally reamed cavities exceeded the experimental reamer's results (P < .005). Conventional acetabular reamers cut bone inaccurately. Reamers designed for improved bone cutting reduce cavity errors.

Press-fit acetabular cup fixation: principles and testing

Pre-clinical testing of the fixation of press-fit acetabular components of total hip prostheses relies on cadaver or synthetic bone, but the properties and geometry of bone models differ from those of physiological bone. Cup designs use varied mechanisms for initial stability in bone; therefore, using different analogues and tests is appropriate. Press-fit cup stability was tested in the following: firstly, polyurethane (PU) foam modelling cancellous support; secondly, glass-fibre reinforced epoxide (GFRE) tubes modelling acetabular cortical support; thirdly, cadaveric acetabula. Three commercial cups [Harris-Galante II (H-G-II), Zimmer; Optifix, Smith & Nephew, Richards; porous coated anatomic (PCA), Howmedica] and an experimental cup with enhanced rim fixation were tested in three modes: direct pull-out, lever-out and axial torque. The fixation stabilities measured in the PU and the GFRE models showed trends consistent with those in cadaver bone, differing in the oversizing and cup geometry. The experimental cup was significantly more secure in most modes than other cups; the H-G II and Optifix cups showed similar stabilities, lower than that of the experimental cup but greater than that of the PCA cup (analysis of variance and Tukey's highly significant test; p < 0.001). The stabilities measured in cadaver bone more closely approximated those in GFRE. The use of several bone analogues enables separation of fixation mechanisms, allowing more accurate prediction of in vivo performance.

Gothenburg osseointegrated hip arthroplasty. Experience with a novel type of hip design

The culmination of more than 10 years of laboratory and clinical research has been the clinical trial of a novel hip arthroplasty for osseointegration. The femoral component of this Gothenburg hip is a neck retaining, threaded fixture with rotational symmetry, produced in commercially pure titanium with a specific surface texture. Proximally, a standard orthopaedic taper trunnion mates with a 28-mm diameter zirconia head that articulates against the acetabular component. The latter is also of textured commercially pure titanium, encapsulating a thick ultra high molecular weight polyethylene liner. Dedicated alignment guides and cutting instruments ensure accurate bone preparation and implant placement. Limited clinical trials commenced in 1992 and expanded to multicenter clinical trials in 1997. Every hip has been monitored with radiostereometry to measure migration to an accuracy of 0.1 mm. All calcar implanted femoral components show excellent function at 4 to 5 years followup, with no migration revealed by radiostereometry.

Dissociation in bulimic and non-eating-disordered women

A relationship between dissociative experiences and the eating disorders has been reported. However the nature of that link is not clearly understood. This study investigates the links between dissociation (as measured by the Dissociative Experiences Scale-DES II) and eating psychopathology in a clinical group of bulimic women and a nonclinical group of undergraduates. In the nonclinical group, specific dissociative styles were found to be linked with bulimic attitudes on the Eating Attitudes Test. In the eating-disordered group, there was an association between the scales of the DES II and frequency of bringing. This association was primarily due to the effects of the dissociative style of absorption (e.g., daydreaming). Suggestions are made for further research, and the clinical implications of the findings are discussed.

A device for producing experimental fractures

A device is reported for the production of transverse fractures of canine tibiae by a three-point bending technique. With strain-gauged load arms, the device enables simultaneous measurement of the bend strength of the intact bone. Results from a series of 14 dogs confirm the reproducibility of this technique.

Carbon fiber reinforced plastic (CFRP) plates versus stainless steel dynamic compression plates in the treatment of fractures of the tibiae in dogs

In a series of 14 dogs, fractures of both tibiae were caused by a "bone-breaker" designed in the authors' department and observed to produce a consistent and realistic canine fracture. One tibia was plated with a carbon fiber reinforced plastic (CFRP) plate and the other with a dynamic compression (DC) plate. Roentgenographic examination demonstrated healing of the CFRP-plated tibiae with abundant callus, and almost total remodeling of the fracture callus between ten and 20 weeks. Biomechanical testing by three-point bending revealed little difference between the strength of union of the fractures at 12-16 weeks. At 20 weeks, although the numbers were too small for statistical confirmation, the CFRP-plated tibiae were consistently stronger than the DC-plated tibiae.

Designing an implant by CT scanning and solid modelling. Arthrodesis of the shoulder after excision of the upper humerus

Techniques are described by which metal implants can be designed and produced to fit precisely a bony site at a subsequent operation. CT scans and solid modelling were used to produce an accurate three-dimensional representation of the surface of the bone. These techniques were applied to the production of an internal fixation device for shoulder arthrodesis after the resection of a neoplasm of the proximal humerus. The reconstruction utilised a free vascularised fibular graft between the scapula and the distal humeral remnant, fixation being secured with the custom-made implant.