Lutetium oxodotreotide (177Lu-Dotatate) for the treatment of unresectable or metastatic progressive gastroenteropancreatic neuroendocrine tumors: a cost-effectiveness analysis for Scotland

Neuroendocrine neoplasms: Consensus on a patient care pathway

People with neuroendocrine neoplasms (NENs) face a multitude of challenges, including delayed diagnosis, low awareness of the cancer among healthcare professionals and limited access to multidisciplinary care and expert centres. We have developed the first patient care pathway for people living with NENs in England to guide disease management and help overcome these barriers. The pathway was developed in two phases. First, a pragmatic review of the literature was conducted, which was used to develop a draft patient care pathway. Second, the draft pathway was then updated following semi-structured interviews with carefully selected expert stakeholders. After each phase, the pathway was discussed among a multidisciplinary, expert advisory group (which comprised the authors and the Deputy Chief Operating Officer, West Suffolk NHS Foundation Trust), who reached a consensus on the ideal care pathway. This article presents the outputs of this research. The pathway identified key barriers to care and highlighted how these may be addressed, with many of the findings relevant to the rest of the UK and international audiences. NENs are increasing in incidence and prevalence in England, compounding pre-existing inequities in diagnosis and disease management. Effective integration of this pathway within NHS England will help achieve optimal, equitable care provision for all people with NENs, and should be feasible within the existing expert multidisciplinary teams across the country.

Levels of PIVKA-II and alpha-fetoprotein in unresectable hepatocellular carcinoma compared to healthy controls and predictive values of both markers with radiological responses after loco-regional interventions

Background

The significance of the current study was to determine normative levels of PIVKA-II and AFP in patients with unresectable HCC and healthy participants. The second goal was to assess the roles of PIVKA-II and AFP in predicting radiological response after loco-regional therapy.

Methods

This prospective cohort study enrolled consecutive samples of HCC patients and healthy controls. Venous blood samples were obtained at baseline and after interventions to determine serum levels of PIVKA-II and AFP using the chemiluminescent microparticle immunoassay method. Radiologic responses were determined based on the WHO criteria.

Results

Fifty-four HCC patients (mean age 58.9 years, 49 males) and 40 healthy controls (mean age 33.5 years, 26 males) were recruited. The median serum levels of PIVKA-II and AFP in HCC vs. healthy controls were 988.4 vs. 24.2 mAU/ml and 13.6 vs. 1.7 ng/ml, respectively (both p < 0.001). With ROC curve analysis, the area under the curve (AUC) for PIVKA-II was 0.95 95% CI [0.90-0.99], and for AFP it was 0.98, 95% CI [0.95-1.0]). The cut-off value for PIVKA-II was 41.4 mAU/ml, and AFP was 4.8 ng/ml. PIVKA-II levels correlated significantly with radiological responses (r = 0.64, p = 0.02) but not AFP (r = 0.09, p = 0.2).

Conclusion

PIVKA-II and AFP levels are distinctive between unresectable HCC and healthy controls. However, PIVKA-II, not AFP, can predict the radiological response after loco-regional therapy.

Cost-Effectiveness Analysis of 177Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer

BACKGROUND

Metastatic castration-resistant prostate cancer poses a therapeutic challenge with poor prognosis. The VISION trial showed prolonged progression-free and overall survival in patients treated with lutetium Lu 177 vipivotide tetraxetan (177Lu-PSMA-617) radioligand therapy compared with using the standard of care (SoC) alone. The objective of this study was to determine the cost-effectiveness of 177Lu-PSMA-617 treatment compared with SoC therapy.

METHODS

A partitioned survival model was developed using data from the VISION trial, which included overall and progression-free survival and treatment regimens for 177Lu-PSMA-617 and SoC. Treatment costs, utilities for health states, and adverse events were derived from public databases and the literature. Because 177Lu-PSMA-617 was only recently approved, costs for treatment were extrapolated from 177Lu-DOTATATE. Outcome measurements included the incremental cost, effectiveness, and cost-effectiveness ratio. The analysis was performed in a US setting from a healthcare system perspective over the lifetime horizon of 60 months. The willingness-to-pay threshold was set to $50,000, $100,000, and $200,000 per quality-adjusted life years (QALYs).

RESULTS

The 177Lu-PSMA-617 group was estimated to gain 0.42 incremental QALYs. Treatment using 177Lu-PSMA-617 led to an increase in costs compared with SoC ($169,110 vs $85,398). The incremental cost, effectiveness, and cost-effectiveness ratio for 177Lu-PSMA-617 therapy was $200,708/QALYs. Sensitivity analysis showed robustness of the model regarding various parameters, which remained cost-effective at all lower and upper parameter bounds. In probabilistic sensitivity analysis using Monte Carlo simulation with 10,000 iterations, therapy using 177Lu-PSMA-617 was determined as the cost-effective strategy in 37.14% of all iterations at a willingness-to-pay threshold of $200,000/QALYs.

CONCLUSIONS

Treatment using 177Lu-PSMA-617 was estimated to add a notable clinical benefit over SoC alone. Based on the model results, radioligand therapy represents a treatment strategy for patients with metastatic castration-resistant prostate cancer with cost-effectiveness in certain scenarios.

Real-world comparison of healthcare resource utilization and costs of [177Lu]Lu-DOTA-TATE in patients with progressive neuroendocrine tumors in England: a matched cohort analysis using data from the hospital episode statistics dataset

OBJECTIVE

To explore the healthcare resource utilization (HCRU) and costs for patients with progressive gastroenteropancreatic neuroendocrine tumors (GEP-NETs) treated with [¹⁷⁷Lu]Lu-DOTA-TATE and matched patients treated with somatostatin analogs (SSAs), chemotherapy, or targeted therapies.

METHODS

Hospital Episode Statistics (HES) dataset 2016-2018 was used to compare HCRU and costs between the two cohorts. The [¹⁷⁷Lu]Lu-DOTA-TATE cohort included patients assigned with a diagnosis code relevant to GEP-NET, a procedure code for imaging or SSAs, and a subsequent code for radionuclide therapy. The non-[¹⁷⁷Lu]Lu-DOTA-TATE cohort included patients assigned with a diagnosis code relevant to GEP-NET who had an increased frequency of SSAs or switched from SSAs to chemotherapy or targeted therapies. Cohorts were matched on propensity scores with sex, age at disease progression, and Charlson Comorbidity Index as parameters. Healthcare Resource Group codes were used for costing.

RESULTS

A total of 199 matched patients were included. The [¹⁷⁷Lu]Lu-DOTA-TATE cohort had lower overall costs (£1,882,028 vs. £3,016,321; p < .0001), non-elective inpatient spells (289 vs. 611 days) and costs (£849,569 vs. £1,707,109; p < .0001 for both), Accident & Emergency costs (£41,978 vs. £62,480; p = .0013), and average length of stay for overall inpatient spells (14.2 vs. 23.3 days; p = .1092) compared with the non-[¹⁷⁷Lu]Lu-DOTA-TATE cohort.

CONCLUSIONS

These analyses indicate significantly lower overall costs and HCRU for progressive GEP-NET patients treated with [¹⁷⁷Lu]Lu-DOTA-TATE. Current research reveals that future real-world analyses would further benefit from using additional databases linked to the HES dataset such as the Clinical Practice Research Datalink and/or National Cancer Registration and Analysis Service database.

Accuracy of two dosimetry software programs for 177Lu radiopharmaceutical therapy using voxel-based patient-specific phantoms

Purpose

Virtual dosimetry using voxel-based patient-specific phantoms and Monte Carlo (MC) simulations offer the advantage of having a gold standard against which absorbed doses may be benchmarked to establish the dosimetry accuracy. Furthermore, these reference values assist in investigating the accuracy of the absorbed dose methodologies from different software programs. Therefore, this study aimed to compare the accuracy of the absorbed doses computed using LundADose and OLINDA/EXM 1.0.

Methods

The accuracy was based on ¹⁷⁷Lu-DOTATATE distributions of three voxel-based phantoms. SPECT projection images were simulated for 1, 24, 96, and 168 h post-administration and reconstructed with LundADose using 3D OS-EM reconstruction. Mono-exponential curves were fitted to the bio-kinetic data for the kidneys, liver, spleen, and tumours resulting in SPECT time-integrated activity (SPECT-TIA). The SPECT-TIA were used to compute mean absorbed doses using LundADose (LND-D_SPECT) and OLINDA (OLINDA-D_SPECT) for the organs. Pre-defined true activity images, were used to obtain TRUE-TIA and, together with full MC simulations, computed the true doses (MC-D_True). The dosimetry accuracy was assessed by comparing LND-D_SPECT and OLINDA-D_SPECT to MC-D_True.

Results

Overall, the results presented an overestimation of the mean absorbed dose by LND-D_SPECT compared to the MC-D_True with a dosimetry accuracy ≤6.6%. This was attributed to spill-out activity from the reconstructed LND-D_SPECT, resulting in a higher dose contribution than the MC-D_True. There was a general underestimation (<8.1%) of OLINDA-D_SPECT compared to MC-D_True attributed to the geometrical difference in shape between the voxel-based phantoms and the OLINDA models. Furthermore, OLINDA-D_SPECT considers self-doses while MC-D_True reflects self-doses plus cross-doses.

Conclusion

The better than 10% accuracy suggests that the mean dose values obtained with LND-D_SPECT and OLINDA-D_SPECT approximate the true values. The mean absorbed doses of the two software programs, and the gold standard were comparable. This work shall be of use for optimising ¹⁷⁷Lu dosimetry for clinical applications.

Survival predictors of 177Lu-Dotatate peptide receptor radionuclide therapy (PRRT) in patients with progressive well-differentiated neuroendocrine tumors (NETS)

Purpose

¹⁷⁷Lu-Dotatate is an emerging treatment modality for patients with unresectable or metastatic well-differentiated NETs. This study examines survival predictors in patients who received ¹⁷⁷Lu-Dotatate.

Methods

A retrospective single-center review was conducted, examining 47 individuals with progressive well-differentiated NETs treated with ¹⁷⁷Lu-Dotatate (four induction cycles of 5.5 GBq at 10-week intervals followed by eight maintenance cycles of 3.7 GBq at 6-month intervals).

Results

Median follow-up was 63.1 months with a median progression-free survival (PFS) of 34.1 months. However, median overall survival (OS) was not reached at the time of analysis. The presence of ≥ 5 bone metastases (hazard ratio HR 4.33; p = 0.015), non-gastroenteropancreatic (non-GEP) NETs (HR 3.22; p = 0.025) and development of interim ascites (HR 3.15; p = 0.047) independently predicted a worse OS. Patients with chromogranin A of ≥ 4 × upper limit of normal (ULN) had shorter OS (p < 0.001) and PFS (p = 0.004). Similarly, those with pre-existing ascites demonstrated a worse OS (p = 0.009) and PFS (p = 0.026). Liver metastases involving greater than 50% liver volume and the existence of unusual metastatic locations had a negative impact on OS (p = 0.033) and PFS (p = 0.026), respectively.

Conclusion

High burden of skeletal and hepatic metastases, non-GEP-NETs, chromogranin A of ≥ 4 × ULN, unusual metastatic sites, pre-existing and interim ascites are predictors of poor outcomes in patients treated with ¹⁷⁷Lu-Dotatate. These common indicators can be used for the risk stratification and identification of patients most likely to benefit from PRRT.

Trial registration

ClinicalTrials.gov identifier: NCT02236910, Retrospectively registered on September, 2014.