[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).

Validation of Prognostic and Predictive Models for Therapeutic Response in Patients Treated with [177Lu]Lu-PSMA-617 Versus Cabazitaxel for Metastatic Castration-resistant Prostate Cancer (TheraP): A Post Hoc Analysis from a Randomised, Open-label, Phase 2 Trial

BACKGROUND

Prognostic models have been developed using data from a multicentre noncomparative study to forecast the likelihood of a 50% reduction in prostate-specific antigen (PSA50), longer prostate-specific antigen (PSA) progression-free survival (PFS), and longer overall survival (OS) in patients with metastatic castration-resistant prostate cancer receiving [177Lu]Lu-PSMA radioligand therapy. The predictive utility of the models to identify patients likely to benefit most from [177Lu]Lu-PSMA compared with standard chemotherapy has not been established.

OBJECTIVE

To determine the predictive value of the models using data from the randomised, open-label, phase 2, TheraP trial (primary objective) and to evaluate the clinical net benefit of the PSA50 model (secondary objective).

DESIGN, SETTING, AND PARTICIPANTS

All 200 patients were randomised in the TheraP trial to receive [177Lu]Lu-PSMA-617 (n = 99) or cabazitaxel (n = 101) between February 2018 and September 2019.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Predictive performance was investigated by testing whether the association between the modelled outcome classifications (favourable vs unfavourable outcome) was different for patients randomised to [177Lu]Lu-PSMA versus cabazitaxel. The clinical benefit of the PSA50 model was evaluated using a decision curve analysis.

RESULTS AND LIMITATIONS

The probability of PSA50 in patients classified as having a favourable outcome was greater in the [177Lu]Lu-PSMA-617 group than in the cabazitaxel group (odds ratio 6.36 [95% confidence interval {CI} 1.69-30.80] vs 0.96 [95% CI 0.32-3.05]; p = 0.038 for treatment-by-model interaction). The PSA50 rate in patients with a favourable outcome for [177Lu]Lu-PSMA-617 versus cabazitaxel was 62/88 (70%) versus 31/85 (36%). The decision curve analysis indicated that the use of the PSA50 model had a clinical net benefit when the probability of a PSA response was ≥30%. The predictive performance of the models for PSA PFS and OS was not established (treatment-by-model interaction: p = 0.36 and p = 0.41, respectively).

CONCLUSIONS

A previously developed outcome classification model for PSA50 was demonstrated to be both predictive and prognostic for the outcome after [177Lu]Lu-PSMA-617 versus cabazitaxel, while the PSA PFS and OS models had purely prognostic value. The models may aid clinicians in defining strategies for patients with metastatic castration-resistant prostate cancer who failed first-line chemotherapy and are eligible for [177Lu]Lu-PSMA-617 and cabazitaxel.

PATIENT SUMMARY

In this report, we validated previously developed statistical models that can predict a response to Lu-PSMA radioligand therapy in patients with advanced prostate cancer. We found that the statistical models can predict patient survival, and aid in determining whether Lu-PSMA therapy or cabazitaxel yields a higher probability to achieve a serum prostate-specific antigen response.

Prognostic and predictive value of non-steroidal anti-inflammatory drugs in the EORTC 1325/KEYNOTE-054 phase III trial of pembrolizumab versus placebo in resected high-risk stage III melanoma

BACKGROUND

Pain is common in patients with cancer. The World Health Organisation recommends paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) for mild pain and combined with other agents for moderate/severe pain. This study estimated associations of NSAIDs with recurrence-free survival (RFS), distant metastasis-free survival (DMFS) and the incidence of immune-related adverse events (irAEs) in high-risk patients with resected melanoma in the EORTC 1325/KEYNOTE-054 phase III clinical trial.

PATIENTS AND METHODS

Patients with AJCC7 stage IIIA, IIIB or IIIC resected melanoma were randomized to receive 200 mg of adjuvant pembrolizumab (N = 514) or placebo (N = 505) 3-weekly for one year or until recurrence. As previously reported, pembrolizumab prolonged RFS and DMFS. NSAID use was defined as administration between 7 days pre-randomization and starting treatment. Multivariable Cox and Fine and Gray models were used to estimate hazard ratios (HRs) for associations of NSAIDs with RFS, DMFS and irAEs.

RESULTS

Of 1019 patients randomized, 59 and 44 patients in the pembrolizumab and placebo arms, respectively, used NSAIDs. NSAIDs were not associated with RFS (HR 0.91, 95% CI 0.58-1.43) or DMFS in the pembrolizumab (HR 1.03, 95% CI 0.65-1.66) or placebo arms (for RFS, HR 0.76, 95% CI 0.48-1.20; for DMFS, HR 0.80, 95% CI 0.49-1.31). NSAIDs were associated with the incidence of irAEs in the placebo arm (HR 3.06, 95% CI 1.45-6.45) but not in the pembrolizumab arm (HR 0.94, 95% CI 0.58-1.53).

CONCLUSION

NSAIDs were not associated with efficacy outcomes nor the risk of irAEs in patients with resected high-risk stage III melanoma receiving adjuvant pembrolizumab.

Real-world health-related quality of life outcomes for patients with resected stage III/IV melanoma treated with adjuvant anti-PD1 therapy

BACKGROUND

While adjuvant therapy with anti-programmed cell death protein-1 (anti-PD1) for patients with resected stage III/IV melanoma has been shown to improve recurrence-free survival, the overall survival benefit remains uncertain. This study aims to evaluate the impact of adjuvant anti-PD1 therapy on the health-related quality of life (HRQOL) of patients with resected stage III/IV melanoma METHODS: Data was used from two melanoma registries in Australia and the Netherlands. Patients with resected stage III/IV melanoma treated with adjuvant anti-PD1 who completed a baseline and at least one post-baseline HRQOL assessment were included. HRQOL was assessed using the EORTC QLQ-C30 at baseline, 3, 6, and 12 months. Established thresholds were used for interpreting changes in QLQ-C30 scores.

RESULTS

92 patients were included. Mean symptom and functioning scores improved or remained stable at 12 months compared to baseline. However, a substantial proportion of patients experienced a clinically significant decline in role (39%, μ = -50.8), social (41%, μ = -32.7), or emotional (50%, μ = -25.1) functioning at 12 months compared to baseline. Younger patients were more likely to experience clinically significant deteriorations in role (OR=1.07, 95% CI: 1.02-1.13, p < 0.01) and social (OR=1.06, 95% CI: 1.01-1.11, p = 0.013) functioning.

CONCLUSION

A significant proportion of patients with resected stage III/IV melanoma who received adjuvant anti-PD1 experienced clinically significant declines in role, social and emotional functioning at 12 months compared to baseline. This highlights the HRQOL issues that may arise during adjuvant anti-PD1 therapy which may require supportive care intervention.

Administering [177Lu]Lu-PSMA-617 Prior to Radical Prostatectomy in Men with High-risk Localised Prostate Cancer (LuTectomy): A Single-centre, Single-arm, Phase 1/2 Study

BACKGROUND

High-risk localised prostate cancer (HRCaP) has high rates of biochemical recurrence; [177Lu]Lu-PSMA-617 is effective in men with advanced prostate cancer.

OBJECTIVE

To investigate the dosimetry, safety, and efficacy of upfront [177Lu]Lu-PSMA-617 in men with HRCaP prior to robotic radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS

In this single-arm, phase I/II trial, we recruited men with HRCaP (any of prostate-specific antigen [PSA] >20 ng/ml, International Society of Urological Pathology (ISUP) grade group [GG] 3-5, and ≥cT2c), with high tumour uptake on [68Ga]Ga-PSMA-11 positron emission tomography/computed tomography (PSMA PET/CT), and scheduled for RP.

INTERVENTION

Cohort A (n = 10) received one cycle and cohort B (n = 10) received two cycles of [177Lu]Lu-PSMA-617 (5 GBq) followed by surgery 6 weeks later.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was tumour radiation absorbed dose. Adverse events (AEs; Common Terminology Criteria for Adverse Events (CTCAE) version 5.0), surgical safety (Clavien-Dindo), imaging, and biochemical responses were evaluated (ClinicalTrials.gov: NCT04430192).

RESULTS AND LIMITATIONS

Between May 29, 2020 and April 28, 2022, 20 patients were enrolled. The median PSA was 18 ng/ml (interquartile range [IQR] 11-35), Eighteen (90%) had GG ≥3, and six (30%) had N1 disease. The median (IQR) highest tumour radiation absorbed dose after cycle 1 for all lesions was 35.5 Gy (19.5-50.1), with 19.6 Gy (11.3-48.4) delivered to the prostate. Five patients received radiation to lymph nodes. Nine (45%) patients achieved >50% PSA decline. The most common AEs related to [177Lu]Lu-PSMA-617 were grade 1 fatigue in eight (40%), nausea in seven (35%), dry mouth in six (30%), and thrombocytopenia in four (20%) patients. No grade 3/4 toxicities or Clavien 3-5 complications occurred. Limitations include small a sample size.

CONCLUSIONS

In men with HRCaP and high prostate-specific membrane antigen (PSMA) expression, [177Lu]Lu-PSMA-617 delivered high levels of targeted radiation doses with few toxicities and without compromising surgical safety. Further studies of [177Lu]Lu-PSMA-617 in this population are worthwhile to determine whether meaningful long-term oncological benefits can be demonstrated.

PATIENT SUMMARY

In this study, we demonstrate that up to two cycles of [177Lu]Lu-PSMA-617 given prior to radical prostatectomy in patients with high-risk localised prostate cancer are safe and deliver targeted doses of radiation to tumour-affected tissues. It is tolerated well with minimal treatment-related adverse events, and surgery is safe with a low rate of complications. Activity measured through PSA reduction, repeat PSMA PET/CT, and histological response is promising.

Olaparib for the Treatment of Patients With Metastatic Castration-Resistant Prostate Cancer and Alterations in BRCA1 and/or BRCA2 in the PROfound Trial

Olaparib improved PFS and OS across subgroups of BRCA1/2mut #prostatecancer patients in the PROFOUND phase III trial.

Novel endoscopic scoring system for immune mediated colitis: A Multicenter Retrospective Study of 674 Patients

BACKGROUND & AIMS

No endoscopic scoring system has been established for immune-mediated colitis (IMC). This study aimed to establish such a system for IMC and explore its utility in guiding future selective immunosuppressive therapy (SIT) use compared to clinical symptoms.

METHODS

This retrospective international 14-center study included 674 patients who developed IMC after immunotherapy and underwent endoscopic evaluation. Ten endoscopic features were selected by group consensus and assigned one point each to calculate an IMC endoscopic score (IMCES). IMCES cutoffs were chosen to maximize specificity for SIT use. This specificity was compared between IMCES, and clinical symptoms graded according to a standardized instrument.

RESULTS

A total of 309 (45.8%) patients received SIT. IMCES specificity for SIT use was 82.8% with a cutoff of 4 . The inclusion of ulceration as a mandatory criterion resulted in higher specificity (85.0% for a cutoff of 4). In comparison, the specificity of a Mayo Endoscopy Score (MES) of 3 was 74.6% while specificity of clinical symptom grading was much lower at 27.4% and 12.3% respectively. Early endoscopy was associated with timely SIT use (p<0.001, r=0.4084).

CONCLUSIONS

This is the largest, multi-center study to devise an endoscopic scoring system to guide IMC management. An IMCES cutoff 4 has a higher specificity for SIT use than clinical symptoms, supporting early endoscopic evaluation for IMC.

Detection of PSMA expression on circulating tumor cells by blood-based liquid biopsy in prostate cancer

Background

For patients with mCRPC, PSMA-targeted radioligand treatment has significantly improved the clinical outcome. A blood-based liquid biopsy assay for recognizing PSMA protein expression on circulating tumor cells may be beneficial for better informing therapeutic decision-making and identifying the patients most likely to benefit from PSMA-targeted radioligand therapy.

Methods

Using high-throughput imaging and digital AI pathology algorithms, a four-color immunofluorescence assay has been developed to find PSMA protein expression on CTCs on a glass slide. Cell line cells (LNCaP/PC3s/22Rv1) spiked into healthy donor blood were used to study the precision, specificity, sensitivity, limit of detection, and overall accuracy of the assay. Clinical validation and low-pass whole-genome sequencing were performed in PSMA-PET-positive patients with high-risk mCRPC (N = 24) utilizing 3 mL of blood.

Results

The PSMA CTC IF assay achieved analytical specificity, sensitivity, and overall accuracy above 99% with high precision. In the clinical validation, 76% (16/21) of the cases were PSMA positive with CTC heterogeneity, and 88% (21/24) of the patients contained at least one conventional CTC per milliliter of blood. Thirty-six low-pass-sequenced CTCs from 11 individuals with mCRPC frequently exhibited copy number increases in AR and MYC and losses in RB1, PTEN, TP53, and BRCA2 locus.

Conclusions

The analytical validation utilizing Epic Sciences' liquid biopsy CTC platform demonstrated the potential to detect PSMA protein expression in CTCs from patients with mCRPC. This assay is positioned as an effective research tool to evaluate PSMA expression, heterogeneity, and therapeutic response in many ongoing clinical studies to target tumors that express PSMA.

The features and management of acquired resistance to PD1-based therapy in metastatic melanoma

BACKGROUND

Anti-PD-1 therapy (PD1) either alone or with anti-CTLA-4 (CTLA4), has high initial response rates, however 20% of patients (pts) with complete response (CR) and 30% with partial response (PR) within 12 months of treatment experience subsequent disease progression by 6 years. The nature and optimal management of this acquired resistance (AR) remains unknown.

METHODS

Pts from 16 centres who responded to PD1-based therapy and who later progressed were examined. Demographics, disease characteristics and subsequent treatments were evaluated.

RESULTS

299 melanoma pts were identified, median age 64y, 44% BRAFV600m. 172 (58%) received PD1 alone, 114 (38%) PD1/CTLA4 and 13 (4%) PD1 and an investigational drug. 90 (30%) pts had CR, 209 (70%) PR. Median time to AR was 12.6 mo (95% CI, 11.3, 14.2). Most (N = 193, 65%) progressed in a single organ site, and in a solitary lesion (N = 151, 51%). The most frequent sites were lymph nodes (38%) and brain (25%). Management at AR included systemic therapy (ST, 45%), local therapy (LT) +ST (31%), LT alone (21%), or observation (3%). There was no statistical difference in PFS2 or OS based on management, however, PFS2 was numerically superior for pts treated with ST alone who progressed off PD1 therapy than those who progressed on PD1 (2-year PFS2 42% versus 25%, p = 0.249). mOS from AR was 38.0 months (95% CI, 29.5-NR); longer in single-site versus multi-site progression (2-year OS 70% vs 54%, p < 0·001).

CONCLUSIONS

Acquired resistance to PD1 therapy in melanoma is largely oligometastatic, and pts may have a favorable survival outcome following salvage treatment.

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.

Increased Thyroidal Activity on Routine FDG-PET/CT after Combination Immune Checkpoint Inhibition: Temporal Associations with Clinical and Biochemical Thyroiditis

BACKGROUND

FDG-PET/CT used for immune checkpoint inhibitor (ICI) response assessment can incidentally identify immune-related adverse events (irAEs), including thyroiditis. This study aimed to correlate the time course of FDG-PET/CT evidence of thyroiditis with clinical and biochemical evolution of thyroid dysfunction.

METHODS

A retrospective review was performed by two independent blinded nuclear medicine physicians (NMPs) of thyroidal FDG uptake in 127 patients who underwent PET/CT between January 2016 and January 2019 at baseline and during treatment monitoring of combination ICI therapy for advanced melanoma. Interobserver agreement was assessed and FDG-PET/CT performance defined by a receiver-operating characteristic (ROC) curve using thyroid function tests (TFTs) as the standard of truth. Thyroid maximum standardized uptake value (SUVmax) and its temporal changes with respect to the longitudinal biochemistry were serially recorded.

RESULTS

At a median of 3 weeks after commencing ICI, 43/127 (34%) had a diagnosis of thyroiditis established by abnormal TFTs. FDG-PET/CT was performed at baseline and at a median of 11 weeks (range 3-32) following the start of therapy. ROC analysis showed an area under the curve of 0.87 (95% CI 0.80, 0.94) for FDG-PET/CT for detection of thyroiditis with a positive predictive value of 93%. Among patients with biochemical evidence of thyroiditis, those with a positive FDG-PET/CT were more likely to develop overt hypothyroidism (77% versus 35%, p < 0.01). In the evaluation of the index test, there was an almost perfect interobserver agreement between NMPs of 93.7% (95% CI 89.4-98.0), kappa 0.83.

CONCLUSION

Increased metabolic activity of the thyroid on routine FDG-PET/CT performed for tumoral response of patients undergoing ICI therapy is generally detected well after routine biochemical diagnosis. Elevation of FDG uptake in the thyroid is predictive of overt clinical hypothyroidism and suggests that an ongoing robust inflammatory response beyond the initial thyrotoxic phase may be indicative of thyroid destruction.

Imaging for assessment of cancer treatment response to immune checkpoint inhibitors can be complementary in identifying hypophysitis

Introduction

Hypophysitis is reported in 8.5%-14% of patients receiving combination immune checkpoint inhibition (cICI) but can be a diagnostic challenge. This study aimed to assess the role of routine diagnostic imaging performed during therapeutic monitoring of combination anti-CTLA-4/anti-PD-1 treatment in the identification of hypophysitis and the relationship of imaging findings to clinical diagnostic criteria.

Methods

This retrospective cohort study identified patients treated with cICI between January 2016 and January 2019 at a quaternary melanoma service. Medical records were reviewed to identify patients with a documented diagnosis of hypophysitis based on clinical criteria. Available structural brain imaging with magnetic resonance imaging (MRI) or computed tomography (CT) of the brain and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography with computed tomography (FDG-PET/CT) were assessed retrospectively. The main radiological outcome measures were a relative change in pituitary size or FDG uptake temporally attributed to cICI.

Results

There were 162 patients (median age 60 years, 30% female) included. A total of 100 and 134 had serial CT/MRI of the brain and FDG-PET/CT, respectively. There were 31 patients who had a documented diagnosis of hypophysitis and an additional 20 who had isolated pituitary imaging findings. The pituitary gland enlargement was mild, and the largest absolute gland size was 13 mm, with a relative increase of 7 mm from baseline. There were no cases of optic chiasm compression. Pituitary enlargement and increased FDG uptake were universally transient. High-dose glucocorticoid treatment for concurrent irAEs prevented assessment of the pituitary-adrenal axis in 90% of patients with isolated imaging findings.

Conclusion

Careful review of changes in pituitary characteristics on imaging performed for assessment of therapeutic response to iICI may lead to increased identification and more prompt management of cICI-induced hypophysitis.

The role of diabetes in metastatic melanoma patients treated with nivolumab plus relatlimab

BACKGROUND

The combination of nivolumab + relatlimab is superior to nivolumab alone in the treatment of naive patients and has activity in PD-1 refractory melanoma. We had previously observed a reduced expression of LAG3 in melanoma tissue from patients with type 2 diabetes.

METHOD

To evaluate the impact of diabetes on oncological outcomes of patients with advanced melanoma treated with nivolumab plus the LAG3 inhibitor relatlimab we performed a retrospective multicenter study.

RESULTS

Overall, 129 patients were included: 88 without diabetes before the treatment, 37 who were diagnosed with type 2 diabetes before the start of treatment, and 4 without diabetes before treatment who developed immune checkpoint inhibitor-induced diabetes (ICI-DM). PFS was 21.71 months (95% CI: 15.61-27.81) in patients without diabetes, 10.23 months (95% CI: 5.81-14.66) in patients with type 2 diabetes, and 50.85 months (95% CI: 23.04-78.65) in patients who developed ICI-DM. OS was 37.94 months (95% CI: 31.02-44.85) in patients without diabetes, 22.12 months (95% CI: 14.41-29.85) in those with type 2 diabetes and 57.64 months (95% CI: 42.29-72.99) in those who developed ICI-DM. Multivariate analysis showed that the presence of diabetes and LDH was correlated with OS and PFS. The mean OS was 64.63 months in subjects with low levels of glucose (< 137 mg/dl) and 36.27 months in those with high levels (hazard ratio 0.16, 95% CI: 0.04-0.58; p = 0.005). The patients whose glucose blood level increased after 3 months of treatment with nivolumab + relatinib compared to baseline (ratio of blood level at baseline/after 3 months > 1.5) had a worse prognosis than those whose glucose level had not increased. This result was observed also in subgroups treated either in first line or further lines. Patients who developed ICI-DM during the study period had better outcomes than the overall population and patients without diabetes.

CONCLUSIONS

LAG3 inhibition for treating metastatic or unresectable melanoma has a reduced efficacy in patients with type 2 diabetes, possibly due to a low expression of LAG3 in tumor tissue. Higher level evidence should be obtained.

Bempegaldesleukin Plus Nivolumab in Untreated Advanced Melanoma: The Open-Label, Phase III PIVOT IO 001 Trial Results

PURPOSE

Despite marked advances in the treatment of unresectable or metastatic melanoma, the need for novel therapies remains. Bempegaldesleukin (BEMPEG), a pegylated interleukin-2 (IL-2) cytokine prodrug, demonstrated efficacy in the phase II PIVOT-02 trial. PIVOT IO 001 (ClinicalTrials.gov identifier: NCT03635983) is a phase III, randomized, open-label study that builds on the PIVOT-02 results in first-line melanoma.

METHODS

Patients with previously untreated, unresectable, or metastatic melanoma were randomly assigned 1:1 to receive BEMPEG plus nivolumab (NIVO) or NIVO monotherapy. Primary end points were objective response rate (ORR) and progression-free survival (PFS) by blinded independent central review and overall survival (OS). Secondary and exploratory end points included additional efficacy measures, safety, and pharmacokinetics (PKs) and pharmacodynamics analyses.

RESULTS

In 783 patients (n = 391, BEMPEG plus NIVO; n = 392, NIVO monotherapy), the median follow-up was 11.6 months in the intent-to-treat population. The ORR with BEMPEG plus NIVO was 27.7% versus 36.0% with NIVO (two-sided P = .0311). The median PFS with BEMPEG plus NIVO was 4.17 months (95% CI, 3.52 to 5.55) versus 4.99 months (95% CI, 4.14 to 7.82) with NIVO (hazard ratio [HR], 1.09; 97% CI, 0.88 to 1.35; P = .3988). The median OS was 29.67 months (95% CI, 22.14 to not reached [NR]) with BEMPEG plus NIVO versus 28.88 months (95% CI, 21.32 to NR) with NIVO (HR, 0.94; 99.929% CI, 0.59 to 1.48; P = .6361). Grade 3-4 treatment-related adverse events (AEs) and serious AE rates were higher with the combination (21.7% and 10.1%, respectively) versus NIVO (11.5% and 5.5%, respectively). BEMPEG PK exposure and absolute lymphocyte count changes after BEMPEG plus NIVO were comparable between PIVOT IO 001 and PIVOT-02.

CONCLUSION

The PIVOT IO 001 study did not meet its primary end points of ORR, PFS, and OS. Increased toxicity was observed with BEMPEG plus NIVO versus NIVO.

The landscape of cell-free mitochondrial DNA in liquid biopsy for cancer detection

BACKGROUND

Existing methods to detect tumor signal in liquid biopsy have focused on the analysis of nuclear cell-free DNA (cfDNA). However, non-nuclear cfDNA and in particular mitochondrial DNA (mtDNA) has been understudied. We hypothesize that an increase in mtDNA in plasma could reflect the presence of cancer, and that leveraging cell-free mtDNA could enhance cancer detection.

RESULTS

We survey 203 healthy and 664 cancer plasma samples from three collection centers covering 12 cancer types with whole genome sequencing to catalogue the plasma mtDNA fraction. The mtDNA fraction is increased in individuals with cholangiocarcinoma, colorectal, liver, pancreatic, or prostate cancer, in comparison to that in healthy individuals. We detect almost no increase of mtDNA fraction in individuals with other cancer types. The mtDNA fraction in plasma correlates with the cfDNA tumor fraction as determined by somatic mutations and/or copy number aberrations. However, the mtDNA fraction is also elevated in a fraction of patients without an apparent increase in tumor-derived cfDNA. A predictive model integrating mtDNA and copy number analysis increases the area under the curve (AUC) from 0.73 when using copy number alterations alone to an AUC of 0.81.

CONCLUSIONS

The mtDNA signal retrieved by whole genome sequencing has the potential to boost the detection of cancer when combined with other tumor-derived signals in liquid biopsies.

Niraparib plus abiraterone acetate with prednisone in patients with metastatic castration-resistant prostate cancer and homologous recombination repair gene alterations: second interim analysis of the randomized phase III MAGNITUDE trial

BACKGROUND

Patients with metastatic castration-resistant prostate cancer (mCRPC) and BRCA alterations have poor outcomes. MAGNITUDE found patients with homologous recombination repair gene alterations (HRR+), particularly BRCA1/2, benefit from first-line therapy with niraparib plus abiraterone acetate and prednisone (AAP). Here we report longer follow-up from the second prespecified interim analysis (IA2).

PATIENTS AND METHODS

Patients with mCRPC were prospectively identified as HRR+ with/without BRCA1/2 alterations and randomized 1 : 1 to niraparib (200 mg orally) plus AAP (1000 mg/10 mg orally) or placebo plus AAP. At IA2, secondary endpoints [time to symptomatic progression, time to initiation of cytotoxic chemotherapy, overall survival (OS)] were assessed.

RESULTS

Overall, 212 HRR+ patients received niraparib plus AAP (BRCA1/2 subgroup, n = 113). At IA2 with 24.8 months of median follow-up in the BRCA1/2 subgroup, niraparib plus AAP significantly prolonged radiographic progression-free survival {rPFS; blinded independent central review; median rPFS 19.5 versus 10.9 months; hazard ratio (HR) = 0.55 [95% confidence interval (CI) 0.39-0.78]; nominal P = 0.0007} consistent with the first prespecified interim analysis. rPFS was also prolonged in the total HRR+ population [HR = 0.76 (95% CI 0.60-0.97); nominal P = 0.0280; median follow-up 26.8 months]. Improvements in time to symptomatic progression and time to initiation of cytotoxic chemotherapy were observed with niraparib plus AAP. In the BRCA1/2 subgroup, the analysis of OS with niraparib plus AAP demonstrated an HR of 0.88 (95% CI 0.58-1.34; nominal P = 0.5505); the prespecified inverse probability censoring weighting analysis of OS, accounting for imbalances in subsequent use of poly adenosine diphosphate-ribose polymerase inhibitors and other life-prolonging therapies, demonstrated an HR of 0.54 (95% CI 0.33-0.90; nominal P = 0.0181). No new safety signals were observed.

CONCLUSIONS

MAGNITUDE, enrolling the largest BRCA1/2 cohort in first-line mCRPC to date, demonstrated improved rPFS and other clinically relevant outcomes with niraparib plus AAP in patients with BRCA1/2-altered mCRPC, emphasizing the importance of identifying this molecular subset of patients.

Efficacy of immune checkpoint inhibitors for the treatment of advanced melanoma in patients with concomitant chronic lymphocytic leukemia

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the management of advanced melanoma (AM). However, data on ICI effectiveness have largely been restricted to clinical trials, thereby excluding patients with co-existing malignancies. Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia and is associated with increased risk of melanoma. CLL alters systemic immunity and can induce T-cell exhaustion, which may limit the efficacy of ICIs in patients with CLL. We, therefore, sought to examine the efficacy of ICI in patients with these co-occurring diagnoses.

PATIENTS AND METHODS

In this international multicenter study, a retrospective review of clinical databases identified patients with concomitant diagnoses of CLL and AM treated with ICI (US-MD Anderson Cancer Center, N = 24; US-Mayo Clinic, N = 15; AUS, N = 19). Objective response rates (ORRs), assessed by RECIST v1.1, and survival outcomes [overall survival (OS) and progression-free survival (PFS)] among patients with CLL and AM were assessed. Clinical factors associated with improved ORR and survival were explored. Additionally, ORR and survival outcomes were compared between the Australian CLL/AM cohort and a control cohort of 148 Australian patients with AM alone.

RESULTS

Between 1997 and 2020, 58 patients with concomitant CLL and AM were treated with ICI. ORRs were comparable between AUS-CLL/AM and AM control cohorts (53% versus 48%, P = 0.81). PFS and OS from ICI initiation were also comparable between cohorts. Among CLL/AM patients, a majority were untreated for their CLL (64%) at the time of ICI. Patients with prior history of chemoimmunotherapy treatment for CLL (19%) had significantly reduced ORRs, PFS, and OS.

CONCLUSIONS

Our case series of patients with concomitant CLL and melanoma demonstrate frequent, durable clinical responses to ICI. However, those with prior chemoimmunotherapy treatment for CLL had significantly worse outcomes. We found that CLL disease course is largely unchanged by treatment with ICI.

Copy number architectures define treatment-mediated selection of lethal prostate cancer clones

Despite initial responses to hormone treatment, metastatic prostate cancer invariably evolves to a lethal state. To characterize the intra-patient evolutionary relationships of metastases that evade treatment, we perform genome-wide copy number profiling and bespoke approaches targeting the androgen receptor (AR) on 167 metastatic regions from 11 organs harvested post-mortem from 10 men who died from prostate cancer. We identify diverse and patient-unique alterations clustering around the AR in metastases from every patient with evidence of independent acquisition of related genomic changes within an individual and, in some patients, the co-existence of AR-neutral clones. Using the genomic boundaries of pan-autosome copy number changes, we confirm a common clone of origin across metastases and diagnostic biopsies, and identified in individual patients, clusters of metastases occupied by dominant clones with diverged autosomal copy number alterations. These autosome-defined clusters are characterized by cluster-specific AR gene architectures, and in two index cases are topologically more congruent than by chance (p-values 3.07 × 10-8 and 6.4 × 10-4). Integration with anatomical sites suggests patterns of spread and points of genomic divergence. Here, we show that copy number boundaries identify treatment-selected clones with putatively distinct lethal trajectories.

Novel radionuclide therapy combinations in prostate cancer

Prostate cancer remains the commonest cancer diagnosed in males and a leading cause of cancer-related death. Men with metastatic castration-resistant prostate cancer (mCRPC) who have progressed on chemotherapy and androgen receptor pathway inhibitors (ARPI) have limited treatment options, significant morbidity, and poor outcomes. Prostate-specific membrane antigen (PSMA)-directed radionuclide therapy (RNT) is emerging as an efficacious and well-tolerated therapy; however, disease progression is universal. Several ongoing RNT trials focus on combination strategies to improve efficacy and durability of treatment response, including combinations with ARPIs, chemotherapy, immunotherapy, and targeted therapies. Further, efforts are underway to expand the role of PSMA-directed RNT to earlier stages of disease including hormone-sensitive and localized prostate cancer. In this review, we discuss the rationale and ongoing RNT combination therapeutic trials in prostate cancer and summarize the efficacy and toxicity associated with RNT.

Prognostic and predictive value of metformin in the European Organisation for Research and Treatment of Cancer 1325/KEYNOTE-054 phase III trial of pembrolizumab versus placebo in resected high-risk stage III melanoma

BACKGROUND

Metformin is a commonly prescribed and well-tolerated medication. In laboratory studies, metformin suppresses BRAF wild-type melanoma cells but accelerates the growth of BRAF-mutated cells. This study investigated the prognostic and predictive value of metformin, including with respect to BRAF mutation status, in the European Organisation for Research and Treatment of Cancer 1325/KEYNOTE-054 randomised controlled trial.

METHODS

Patients with resected high-risk stage IIIA, IIIB, or IIIC melanoma received 200 mg of pembrolizumab (n = 514) or placebo (n = 505) every 3 weeks for twelve months. Pembrolizumab prolonged recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) at approximately 42 months median follow-up (Eggermont et al., TLO, 2021). Multivariable Cox regression was used to estimate associations of metformin with RFS and DMFS. Interaction terms were used to model effect modification by treatment and BRAF mutation.

RESULTS

Fifty-four patients (0.5%) used metformin at baseline. Metformin was not significantly associated with RFS (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.52-1.45) and DMFS (HR 0.82, 95% CI 0.47-1.44). The interaction between metformin and the treatment arm was not significant for either RFS (p = 0.92) or DMFS (p = 0.93). Among patients with mutated BRAF, the association of metformin with RFS (HR 0.70, 95% CI 0.37-1.33) was greater in magnitude though not significantly different to those without mutated BRAF (HR 0.98, 95% CI 0.56-1.69).

CONCLUSIONS

There was no significant impact of metformin use on pembrolizumab efficacy in resected high-risk stage III melanoma. However, larger studies or pooled analyses are needed, particularly to explore a possible effect of metformin in BRAF-mutated melanoma.

Adjuvant therapy for stage II melanoma: the need for further studies

Immunotherapy with checkpoint inhibitors has revolutionised the outcomes for melanoma patients. In the metastatic setting, patients treated with nivolumab and ipilimumab have an expected 5-year survival of> 50%. For patients with resected high-risk stage III disease, adjuvant pembrolizumab, nivolumab or dabrafenib and trametinib are associated with a significant improvement in both relapse-free survival (RFS) and distant metastasis-free survival (DMFS). More recently neoadjuvant immunotherapy has shown very promising outcomes in patients with clinically detectable nodal disease and is likely to become a new standard of care. For stage IIB/C disease, two pivotal adjuvant trials of pembrolizumab and nivolumab have also reported a significant improvement in both RFS and DMFS. However, the absolute benefit is low and there are concerns about the risk of severe toxicities as well as long-term morbidity from endocrine toxicity. Ongoing registration phase III trials are currently evaluating newer immunotherapy combinations and the role of BRAF/MEK-directed targeted therapy for stage II melanoma. However, our ability to personalise therapy based on molecular risk stratification has lagged behind the development of novel immune therapies. There is a critical need to evaluate the use of tissue and blood-based biomarkers, to better select patients that will recur and avoid unnecessary treatment for the majority of patients cured by surgery alone.

Volunteers as a resource for asset mapping and maintaining a living resource directory: lessons from an academic-community partnership

AIMS

Health and social services are fundamental to public and population health, and disruptions can have devastating effects on individuals of all ages. During the first wave of the COVID-19 pandemic, the availability of health and social services rapidly changed. Existing resources experienced changes in operation and mode of service delivery, while new resources emerged to address escalating needs. Both the general public and service providers lacked access to accurate information on availability and access, and existing service directories became obsolete or unreliable. To address this gap, a committee of university students expanded its volunteer base, partnered with a local non-profit organization, and invested in maintaining a centralized, up-to-date resource directory for the region.

METHODS/RESULTS

Student volunteers sourced and consolidated existing county-level directories to curate more than 370 resources across 12 healthcare and social care domains in a Google Sheets platform. This directory was publicly accessible, available in English and Spanish, adjustable to community feedback and needs, disseminated through the local health system intranet, synthesized into paper handouts for food pantries, and utilized to curate a directory aimed toward older adult needs. Students worked in a tiered leadership model and mobilized quickly to respond to immediate community needs.

CONCLUSION

This academic-community partnership engaging student volunteers can be a low-cost, high-value resource to support public health systems meet the information needs of their community, particularly during periods of crisis or rapid changes in service availability.

Health-related quality of life in GALAHAD: A multicenter, open-label, phase 2 study of niraparib for patients with metastatic castration-resistant prostate cancer and DNA-repair gene defects

BACKGROUND: Niraparib is a highly selective poly (adenosine diphosphateribose) polymerase-1 and poly (adenosine diphosphate-ribose) polymerase-2 inhibitor indicated for select patients with ovarian, fallopian tube, and primary peritoneal cancer. The phase 2 GALAHAD trial (NCT02854436) demonstrated that niraparib monotherapy is tolerable and efficacious in patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) gene alterations, particularly those with breast cancer gene (BRCA) alterations who had progressed on prior androgen signaling inhibitor therapy and taxane-based chemotherapy. OBJECTIVE: To report the prespecified patient-reported outcomes analysis from GALAHAD. METHODS: Eligible patients with alterations to BRCA1 and/or BRCA2 (BRCA cohort) and with pathogenic alterations in other HRR genes (other HRR cohort) were enrolled and received niraparib 300 mg once daily. Patient-reported outcome instruments included the Functional Assessment of Cancer Therapy-Prostate and the Brief Pain Inventory-Short Form. Changes from baseline were compared using a mixed-effect model for repeated measures. RESULTS: On average, health-related quality of life (HRQoL) improved in the BRCA cohort by cycle 3 (mean change = 6.03; 95% CI = 2.76-9.29) and was maintained above baseline until cycle 10 (mean change = 2.84; 95% CI = -1.95 to 7.63), whereas the other HRR cohort showed no early change in HRQoL from baseline (mean change = -0.07; 95% CI = -4.69 to 4.55) and declined by cycle 10 (mean change = -5.10; 95% CI = -15.3 to 5.06). Median time to deterioration in pain intensity and pain interference could not be estimated in either cohort. CONCLUSIONS: Patients with advanced mCRPC and BRCA alterations treated with niraparib experienced more meaningful improvement in overall HRQoL, pain intensity, and pain interference compared with those with other HRR alterations. In this population of castrate, heavily pretreated patients with mCRPC and HRR alterations, stabilization, and improvement in HRQoL may be relevant to consider when making treatment decisions. DISCLOSURES: This work was supported by Janssen Research & Development, LLC (no grant number). Dr Smith has received grants and personal fees from Bayer, Amgen, Janssen, and Lilly; and has received personal fees from Astellas Pharma, Novartis, and Pfizer. Dr Sandhu has received grants from Amgen, Endocyte, and Genentech; has received grants and personal fees from AstraZeneca and Merck; and has received personal fees from Bristol Myers Squibb and Merck Serono. Dr George has received personal fees from the American Association for Cancer Research, Axess Oncology, Capio Biosciences, Constellation Pharma, EMD Serono, Flatiron, Ipsen, Merck Sharp & Dohme, Michael J. Hennessey Association, Millennium Medical Publishing, Modra Pharma, Myovant Sciences, Inc., NCI Genitourinary, Nektar Therapeutics, Physician Education Resource, Propella TX, RevHealth, LLC, and UroGPO; has received grants and personal fees from Astellas Pharma, AstraZeneca, Bristol Myers Squibb, and Pfizer; has received personal fees and nonfinancial support from Bayer and UroToday; has received grants from Calithera and Novartis; and has received grants, personal fees, and nonfinancial support from Exelixis, Inc., Sanofi, and Janssen Pharma. Dr Chi has received grants from Janssen during the conduct of the study; has received grants and personal fees from AstraZeneca, Bayer, Astellas Pharma, Novartis, Pfizer, POINT Biopharma, Roche, and Sanofi; and has received personal fees from Daiichi Sankyo, Merck, and Bristol Myers Squibb. Dr Saad has received grants, personal fees, and nonfinancial support from Janssen during the conduct of the study; and has received grants, personal fees, and nonfinancial support from AstraZeneca, Astellas Pharma, Pfizer, Bayer, Myovant, Sanofi, and Novartis. Dr Thiery-Vuillemin has received grants, personal fees, and nonfinancial support from Pfizer; has received personal fees and nonfinancial support from AstraZeneca, Janssen, Ipsen, Roche/Genentech, Merck Sharp & Dohme, and Astellas Pharma; and has received personal fees from Sanofi, Novartis, and Bristol Myers Squibb. Dr Olmos has received grants, personal fees, and nonfinancial support from AstraZeneca, Bayer, Janssen, and Pfizer; has received personal fees from Clovis, Daiichi Sankyo, and Merck Sharp & Dohme; and has received nonfinancial support from Astellas Pharma, F. Hoffman-LaRoche, Genentech, and Ipsen. Dr Danila has received research support from the US Department of Defense, the American Society of Clinical Oncology, the Prostate Cancer Foundation, Stand Up to Cancer, Janssen Research & Development, Astellas Pharma, Medivation, Agensys, Genentech, and CreaTV. Dr Gafanov has received grants from Janssen during the conduct of the study. Dr Castro has received grants from Janssen during the conduct of the study; has received grants and personal fees from Janssen, Bayer, AstraZeneca, and Pfizer; and has received personal fees from Astellas Pharma, Merck Sharp & Dohme, Roche, and Clovis. Dr Moon has received research funding from SeaGen, HuyaBio, Janssen, BMS, Aveo, Xencor, and has received personal fees from Axess Oncology, MJH, EMD Serono, and Pfizer. Dr Joshua has received nonfinancial support from Janssen; consulted or served in an advisory role for Neoleukin, Janssen Oncology, Ipsen, AstraZeneca, Sanofi, Noxopharm, IQvia, Pfizer, Novartis, Bristol Myers Squibb, Merck Serono, and Eisai; and received research funding from Bristol Myers Squibb, Janssen Oncology, Merck Sharp & Dohme, Mayne Pharma, Roche/Genentech, Bayer, MacroGenics, Lilly, Pfizer, AstraZeneca, and Corvus Pharmaceuticals. Drs Mason, Liu, Bevans, Lopez-Gitlitz, and Francis and Mr Espina are employees of Janssen Research & Development. Dr Mason owns stocks with Janssen. Dr Fizazi has participated in advisory boards and talks for Amgen, Astellas, AstraZeneca, Bayer, Clovis, Daiichi Sankyo, Janssen, MSD, Novartis/AAA, Pfizer, and Sanofi, with honoraria to his institution (Institut Gustave Roussy); has participated in advisory boards for, with personal honoraria from, Arvinas, CureVac, MacroGenics, and Orion. Study registration number: NCT02854436.

BRCA1 and BRCA2 carriers with breast, ovarian and prostate cancer demonstrate a different pattern of metastatic disease compared with non-carriers: results from a rapid autopsy programme

AIM

To catalogue and compare the pattern of metastatic disease in germline BRCA1/2 pathogenic mutation carriers and non-carriers with breast, ovarian and prostate cancer from a rapid autopsy programme.

METHODS AND RESULTS

The number of metastases in the major body systems and the proportion of participants with metastases were documented in 50 participants (19 germline mutation carriers). Analysis was conducted on the participants' pattern of disease for the different cancers and mutation subgroups. The four commonly affected organ systems were the digestive (liver only) (82%), respiratory (76%), gastrointestinal (65%) and reticuloendothelial (42%). There were significant differences in the pattern of metastatic breast cancer in BRCA1/2 germline carriers compared with non-carriers. Breast cancer carriers had significantly fewer organ systems involved (median n = 3, range = 1-3) compared with non-carriers (median n = 9, range = 1-7) (P = 0.03). BRCA1/2 carriers with ovarian carcinomas had significantly more organ systems with metastatic carcinoma (median n = 10, range = 3-8) than non-carriers (median n = 5, range = 3-5) (P < 0.001). There were no significant differences in the number of involved systems in BRCA2 carriers compared with non-carriers with prostate cancer (P = 1.0). There was an absence of locoregional disease (6.5%) compared with distant disease (93.5%) among the three cancer subtypes (P < 0.001). The majority of metastatic deposits (97%) collected during the autopsy were identified by recent diagnostic imaging.

CONCLUSION

Even though a major limitation of this study is that our numbers are small, especially in the breast cancer carrier group, the metastatic patterns of breast and ovarian cancers may be impacted by BRCA1/2 carrier status, suggesting that tumours derived from patients with these mutations use different mechanisms of dissemination. The findings may focus clinical diagnostic imaging for monitoring metastases where whole-body imaging resources are scant.

Niraparib and Abiraterone Acetate for Metastatic Castration-Resistant Prostate Cancer

PURPOSE

Metastatic castration-resistant prostate cancer (mCRPC) remains a lethal disease with current standard-of-care therapies. Homologous recombination repair (HRR) gene alterations, including BRCA1/2 alterations, can sensitize cancer cells to poly (ADP-ribose) polymerase inhibition, which may improve outcomes in treatment-naïve mCRPC when combined with androgen receptor signaling inhibition.

METHODS

MAGNITUDE (ClinicalTrials.gov identifier: NCT03748641) is a phase III, randomized, double-blinded study that evaluates niraparib and abiraterone acetate plus prednisone (niraparib + AAP) in patients with (HRR+, n = 423) or without (HRR-, n = 247) HRR-associated gene alterations, as prospectively determined by tissue/plasma-based assays. Patients were assigned 1:1 to receive niraparib + AAP or placebo + AAP. The primary end point, radiographic progression-free survival (rPFS) assessed by central review, was evaluated first in the BRCA1/2 subgroup and then in the full HRR+ cohort, with secondary end points analyzed for the full HRR+ cohort if rPFS was statistically significant. A futility analysis was preplanned in the HRR- cohort.

RESULTS

Median rPFS in the BRCA1/2 subgroup was significantly longer in the niraparib + AAP group compared with the placebo + AAP group (16.6 v 10.9 months; hazard ratio [HR], 0.53; 95% CI, 0.36 to 0.79; P = .001). In the overall HRR+ cohort, rPFS was significantly longer in the niraparib + AAP group compared with the placebo + AAP group (16.5 v 13.7 months; HR, 0.73; 95% CI, 0.56 to 0.96; P = .022). These findings were supported by improvement in the secondary end points of time to symptomatic progression and time to initiation of cytotoxic chemotherapy. In the HRR- cohort, futility was declared per the prespecified criteria. Treatment with niraparib + AAP was tolerable, with anemia and hypertension as the most reported grade ≥ 3 adverse events.

CONCLUSION

Combination treatment with niraparib + AAP significantly lengthened rPFS in patients with HRR+ mCRPC compared with standard-of-care AAP.

[Media: see text].

Safety of Lutetium-177 prostate-specific membrane antigen-617 (PSMA-617) radioligand therapy in the setting of severe renal impairment: a case report and literature review

Reported here is a case of rapidly progressive metastatic castration-resistant prostate cancer treated with [177Lu]Lu-PSMA-617 in the setting of severe renal impairment and impending ureteric obstruction. PSMA is expressed on renal tubular cells, raising the possibility of radiation-induced nephrotoxicity, and this level of renal impairment would typically exclude the patient from [177Lu]Lu-PSMA-617 therapy. Multidisciplinary input, individualized dosimetry, and patient-specific dose reduction were used to ensure the cumulative dose to the kidneys remained within acceptable limits. He was initially planned for treatment with six cycles of [177Lu]Lu-PSMA-617. However, he had an excellent response to therapy following four cycles of treatment and the last two cycles were omitted. He has been followed for 1-year posttherapy without evidence of disease recurrence. No acute or chronic nephrotoxicity was observed. This case report highlights the utility of [177Lu]Lu-PSMA-617 therapy in severe renal impairment and provides evidence of relative safety in patients who would otherwise not be considered candidates for therapy.

Spatial analysis with SPIAT and spaSim to characterize and simulate tissue microenvironments

Spatial proteomics technologies have revealed an underappreciated link between the location of cells in tissue microenvironments and the underlying biology and clinical features, but there is significant lag in the development of downstream analysis methods and benchmarking tools. Here we present SPIAT (spatial image analysis of tissues), a spatial-platform agnostic toolkit with a suite of spatial analysis algorithms, and spaSim (spatial simulator), a simulator of tissue spatial data. SPIAT includes multiple colocalization, neighborhood and spatial heterogeneity metrics to characterize the spatial patterns of cells. Ten spatial metrics of SPIAT are benchmarked using simulated data generated with spaSim. We show how SPIAT can uncover cancer immune subtypes correlated with prognosis in cancer and characterize cell dysfunction in diabetes. Our results suggest SPIAT and spaSim as useful tools for quantifying spatial patterns, identifying and validating correlates of clinical outcomes and supporting method development.

Health-related quality of life in patients with melanoma brain metastases treated with immunotherapy

Aims: To describe the health-related quality of life (HRQoL) of melanoma brain metastasis (MBM) patients throughout the first 18 weeks of ipilimumab-nivolumab or nivolumab treatment. Materials & methods: HRQoL data (European Organisation for Research and Treatment of Cancer's Core Quality of Life Questionnaire, additional Brain Neoplasm Module, and EuroQol 5-Dimension 5-Level Questionnaire) were collected as a secondary outcome of the Anti-PD1 Brain Collaboration phase II trial. Mixed linear modeling assessed changes over time, whereas the Kaplan-Meier method was used to determine median time to first deterioration. Results: Asymptomatic MBM patients treated with ipilimumab-nivolumab (n = 33) or nivolumab (n = 24) maintained baseline HRQoL. MBM patients with symptoms or leptomeningeal/progressive disease treated with nivolumab (n = 14) reported a statistically significant trend toward improvement. Conclusion: MBM patients treated with either ipilimumab-nivolumab or nivolumab did not report a significant deterioration in HRQoL within 18 weeks of treatment initiation. Clinical trial registration: NCT02374242 (ClinicalTrials.gov).

Abstract 5614: Genomic aberrations in circulating tumor DNA (ctDNA) and clinical outcomes from [177Lu]Lu-PSMA-617 in metastatic castration-resistant prostate cancer (mCRPC)

[177Lu]Lu-PSMA-617 (LuPSMA) radionuclide therapy improves overall survival in mCRPC, and was recently approved by the FDA. Nevertheless, owing to the heterogeneous nature of mCRPC, responses to LuPSMA therapy can be variable, and resistance is inevitable. As a result, biomarkers linked to clinical outcome with LuPSMA are urgently required. Using plasma ctDNA, we present the first comprehensive genomic analysis of a prospective cohort of mCRPC patients treated with LuPSMA. Targeted sequencing of 78 genes was performed on baseline plasma and matched buffy coat samples from patients who received LuPSMA on a prospective registry (NCT04769817). Reportable alterations included pathogenic single-nucleotide and copy number variants. Association between alterations and clinical outcomes were assessed using log rank, cox proportional, and chi-squared analyses. Clinical data collected included PSA decline by ≥50% or ≥90% (PSA50-response rate, PSA50-RR; and PSA90-RR), and PSA progression free survival (PSA-PFS). In total, 100 patients (median age 74 years, range 52-90) received a median of 4 cycles of LuPSMA. 83 patients had detectable ctDNA (median fraction 17%, range 0-94%) with PSA50-RR 50%, PSA90-RR 22%, and a median PSA-PFS of 7.2 months. Patients with an AR or PTEN aberration had significantly shorter PSA-PFS (HR 0.50 and 0.59, respectively; Table), as did patients with any PI3K pathway aberration (HR 0.56). Additionally, patients with a high ctDNA burden had significantly worse PSA-PFS (HR 0.42, Table). There were no significant differences in PSA-RR based on deleterious genomic changes. Our data reveal that aberrations in the AR and PI3K pathways, along with pre-treatment ctDNA fraction, whilst not linked to PSA-RR, are prognostic for durability of response to LuPSMA. If validated in larger cohorts, these data will help to optimise the use of LuPSMA by improving patient selection and enhancing prognostication.

Analysis of clinical endpoints based on deleterious genomic changes in ctDNA n PSA-PFS (months, wild type (wt) vs variant) PSA-PFS HR (95% CI, wt vs variant) PSA50-RR (wt vs variant) PSA90-RR (wt vs variant) Exonic AR variants 47 8.1 vs 6.0 p=0.005 0.50 (0.30-0.83) p=0.006 58% vs 40% p=0.09 23% vs 21% p=0.8 Any AR variant (intronic and upstream enhancer regions included) 49 8.1 vs 6.0 p=0.007 0.53 (0.31-0.83) p=0.008 60% vs 41% p=0.09 24% vs 20% p=0.7 RB1 variant 19 7.9 vs 5.5 p=0.2 0.67 (0.39-1.2) p=0.2 51% vs 42% p=0.5 23% vs 21% p=0.9 PTEN variant 25 7.8 vs 6.3 p=0.04 0.59 (0.36-1.00) p=0.045 50% vs 48% p=0.9 22% vs 24% p=0.8 TP53 variant 43 8.1 vs 6.7 p=0.1 0.67 (0.42-1.1) p=0.1 52% vs 47% p=0.6 20% vs 26% p=0.5 BRCA2 variant 10 7.7 vs 5.1 p=0.2 0.63 (0.29-1.30) p=0.2 51% vs 40% p=0.7 20% vs 40% p=0.1 PIK3CA variant 8 7.7 vs 4.1 p=0.08 0.48 (0.20-1.1) p=0.09 52% vs 13% p=0.06 23% vs 13% p=0.5 PI3K pathway variant 35 7.8 vs 5.5 p= 0.02 0.56 (0.34-0.91) p=0.02 55% vs 40% p=0.2 22% vs 23% p=0.9 ctDNA fraction ≥20% 43 9.0 vs 5.1 p=0.0002 0.42 (0.26-0.67) p&lt;0.001 55% vs 42% p=0.2 21% vs 23% p=0.8

Citation Format: Heidi Fettke, Louise Kostos, James Buteau, Jason A. Steen, Elizabeth Medhurst, Mo B. Haskali, Declan Murphy, Maria Docanto, Patricia Bukczynska, Nicole Ng, Shahneen Sandhu, Siavash Foroughi, Luc Furic, Tu Nguyen-Dumont, Michael S. Hofman, Arun A. Azad. Genomic aberrations in circulating tumor DNA (ctDNA) and clinical outcomes from [177Lu]Lu-PSMA-617 in metastatic castration-resistant prostate cancer (mCRPC). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5614.

Durability of response to immune checkpoint inhibitors in metastatic Merkel cell carcinoma after treatment cessation

BACKGROUND

Metastatic Merkel cell carcinoma (mMCC) is highly responsive to immune checkpoint inhibitors (ICIs); however, durability of response after treatment cessation and response to retreatment in the setting of progression is unknown.

METHODS

Patients (pts) having mMCC from 10 centres who discontinued ICI treatment for a reason other than progression were studied.

RESULTS

Forty patients were included. Median time on treatment was 13.5 months (range 1-35). Thirty-one patients (77.5%) stopped treatment electively while 9 patients (22.5%) stopped due to treatment-related toxicity. After median of 12.3 months from discontinuation, 14 pts (35%) have progressed (PD). Disease progression rate following ICI discontinuation was 26% (8 of 31) in patients who discontinued in complete response (CR), 57% (4 of 7) in patients in partial response and 100% (2 of 2) in those with stable disease. Median progression-free survival (PFS) after treatment cessation was 21 months (95% confidence interval [CI], 18- not reached [NR]), with a third of patients progressing during their first year off treatment. PFS was longer for patients who discontinued ICI electively (median PFS 29 months; 95% CI, 21-NR) compared to those who stopped due to toxicity (median PFS 11 months; 95% CI, 10-NR). ICI was restarted in 8 of 14 pts (57%) with PD, with response rate of 75% (4 CR, 2 partial response, 1 stable disease, 1 PD).

CONCLUSION

ICI responses in mMCC do not appear durable off treatment, including in patients who achieve a CR, though response to retreatment is promising. Extended duration of treatment needs to be investigated to optimise long-term outcomes.

Testosterone suppression plus enzalutamide versus testosterone suppression plus standard antiandrogen therapy for metastatic hormone-sensitive prostate cancer (ENZAMET): an international, open-label, randomised, phase 3 trial

BACKGROUND

The interim analysis of the ENZAMET trial of testosterone suppression plus either enzalutamide or standard nonsteroidal antiandrogen therapy showed an early overall survival benefit with enzalutamide. Here, we report the planned primary overall survival analysis, with the aim of defining the benefit of enzalutamide treatment in different prognostic subgroups (synchronous and metachronous high-volume or low-volume disease) and in those who received concurrent docetaxel.

METHODS

ENZAMET is an international, open-label, randomised, phase 3 trial conducted at 83 sites (including clinics, hospitals, and university centres) in Australia, Canada, Ireland, New Zealand, the UK, and the USA. Eligible participants were males aged 18 years or older with metastatic, hormone-sensitive prostate adenocarcinoma evident on CT or bone scanning with ^99mTc and an Eastern Cooperative Oncology Group performance status score of 0-2. Participants were randomly assigned (1:1), using a centralised web-based system and stratified by volume of disease, planned use of concurrent docetaxel and bone antiresorptive therapy, comorbidities, and study site, to receive testosterone suppression plus oral enzalutamide (160 mg once per day) or a weaker standard oral non-steroidal antiandrogen (bicalutamide, nilutamide, or flutamide; control group) until clinical disease progression or prohibitive toxicity. Testosterone suppression was allowed up to 12 weeks before randomisation and for up to 24 months as adjuvant therapy. Concurrent docetaxel (75 mg/m² intravenously) was allowed for up to six cycles once every 3 weeks, at the discretion of participants and physicians. The primary endpoint was overall survival in the intention-to-treat population. This planned analysis was triggered by reaching 470 deaths. This study is registered with ClinicalTrials.gov, NCT02446405, ANZCTR, ACTRN12614000110684, and EudraCT, 2014-003190-42.

FINDINGS

Between March 31, 2014, and March 24, 2017, 1125 participants were randomly assigned to receive non-steroidal antiandrogen (n=562; control group) or enzalutamide (n=563). The median age was 69 years (IQR 63-74). This analysis was triggered on Jan 19, 2022, and an updated survival status identified a total of 476 (42%) deaths. After a median follow-up of 68 months (IQR 67-69), the median overall survival was not reached (hazard ratio 0·70 [95% CI 0·58-0·84]; p<0·0001), with 5-year overall survival of 57% (0·53-0·61) in the control group and 67% (0·63-0·70) in the enzalutamide group. Overall survival benefits with enzalutamide were consistent across predefined prognostic subgroups and planned use of concurrent docetaxel. The most common grade 3-4 adverse events were febrile neutropenia associated with docetaxel use (33 [6%] of 558 in the control group vs 37 [6%] of 563 in the enzalutamide group), fatigue (four [1%] vs 33 [6%]), and hypertension (31 [6%] vs 59 [10%]). The incidence of grade 1-3 memory impairment was 25 (4%) versus 75 (13%). No deaths were attributed to study treatment.

INTERPRETATION

The addition of enzalutamide to standard of care showed sustained improvement in overall survival for patients with metastatic hormone-sensitive prostate cancer and should be considered as a treatment option for eligible patients.

FUNDING

Astellas Pharma.

Impact of concurrent tumor events on the prostate cancer outcomes of germline BRCA2 mutation carriers

BACKGROUND

Several studies have reported the association of germline BRCA2 (gBRCA2) mutations with poor clinical outcomes in prostate cancer (PCa), but the impact of concurrent somatic events on gBRCA2 carriers survival and disease progression is unknown.

PATIENTS AND METHODS

To ascertain the role of frequent somatic genomic alterations and histology subtypes in the outcomes of gBRCA2 mutation carriers and non-carriers, we correlated the tumour characteristics and clinical outcomes of 73 gBRCA2 and 127 non-carriers. Fluorescent in-situ hybridisation and next-generation sequencing were used to detect copy number variations in BRCA2, RB1, MYC and PTEN. Presence of intraductal and cribriform subtypes was also assessed. The independent impact of these events on cause-specific survival (CSS), metastasis-free survival and time to castration-resistant disease was assessed using cox-regression models.

RESULTS

Somatic BRCA2-RB1 co-deletion (41% versus 12%, p < 0.001) and MYC amplification (53.4% versus 18.8%, p < 0.001) were enriched in gBRCA2 compared to sporadic tumours. Median CSS from diagnosis of PCa was 9.1 versus 17.6 years in gBRCA2 carriers and non-carriers, respectively (HR 2.12; p = 0.002), Median CSS in gBRCA2 carriers increased to 11.3 and 13.4 years in the absence of BRCA2-RB1 deletion or MYC amplification, respectively. Median CSS of non-carriers decreased to 8 and 2.6 years if BRCA2-RB1 deletion or MYC amplification were detected.

CONCLUSIONS

gBRCA2-related prostate tumours are enriched for aggressive genomic features, such as BRCA2-RB1 co-deletion and MYC amplification. The presence or absence of these events modify the outcomes of gBRCA2 carriers.

FDG PET/CT Prognostic Markers in Patients with Advanced Melanoma Treated with Ipilimumab and Nivolumab

Background Despite improved response to combined ipilimumab and nivolumab (hereafter, IpiNivo) treatment for advanced melanoma, many patients exhibit primary or acquired resistance. This, combined with high risk of immune-related adverse events, makes identifying markers predictive of outcomes desirable. Purpose To investigate the prognostic value of fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) PET/CT parameters at baseline and as part of response monitoring in patients with advanced melanoma undergoing IpiNivo treatment. Materials and Methods This was a single-center retrospective study of adult patients with melanoma who received IpiNivo. Baseline FDG PET/CT parameters that included metabolic tumor volume (MTV), tumor stage, mutation status, Eastern Cooperative Oncology Group performance score, lactate dehydrogenase level, and treatment line were correlated with overall survival in univariable and multivariable Cox regression analyses. Treatment response as determined with FDG PET/CT was correlated with overall survival. Results In total, 122 patients (median age, 61 years [IQR, 51-69 years]; 89 men) were included; 78% (95 of 122) had an Eastern Cooperative Oncology Group score of 0, 52% (45 of 86) had an elevated lactate dehydrogenase level, 39% (48 of 122) had a metastatic stage of M1c and 45% (55 of 122) M1d, 45% (55 of 122) had BRAF V600E/K mutation, and the median MTV was 42 mL. Patients with a higher than median MTV at baseline FDG PET/CT had a lower 12-month survival rate compared with those with a lower than median MTV (43% [95% CI: 32, 58] vs 66% [95% CI: 55, 79], P < .001). In multivariable analysis, higher versus lower than median MTV, Eastern Cooperative Oncology Group performance scores of 1-2 versus 0, and subsequent versus first-line IpiNivo treatment were independently associated with overall survival (hazard ratio [HR]: 1.68 [95% CI: 1.02, 2.78], P = .04; 3.1 [95% CI: 1.8, 5.4], P < .001; and 11.2 [95% CI: 3.4, 37.1], P = .002, respectively). The 12-month overall survival rate was lower in patients with progressive disease than in those without progression (35% [95% CI: 24, 51] vs 90% [95% CI: 83, 99]; HR, 7.3 [95% CI: 3.9, 13.3]; P < .001). Conclusion Baseline fluorine 18 fluorodeoxyglucose PET/CT metabolic tumor volume was an independent prognostic marker in patients with advanced melanoma who received ipilimumab and nivolumab treatment. © RSNA, 2023 Supplemental material is available for this article.

Evolution: Phase II study of radionuclide 177Lu-PSMA-617 therapy versus 177Lu-PSMA-617 in combination with ipilimumab and nivolumab for men with metastatic castration-resistant prostate cancer (mCRPC; ANZUP 2001)

TPS271

Background: Combination immune checkpoint inhibitors (ICI) with ipilimumab and nivolumab has been shown to induce adaptive immune responses in patients with mCRPC, albeit resulting in modest clinical benefit. There is growing evidence that radiation may enhance the activity of ICI by modulating the tumour immune microenvironment. We hypothesize that the radionuclide 177Lu-PSMA-617 may result in immunogenic cell death and therefore synergise with combination ICI to improve long term clinical outcomes. EVOLUTION aims to determine the activity and safety of ipilimumab and nivolumab in combination with 177Lu-PSMA-617 in patients with mCRPC. Methods: This open label, multicentre, phase 2 study will randomly assign 100 participants with mCRPC in a 2:1 ratio stratified by site and prior exposure to docetaxel to either: the experimental combination of 177Lu-PSMA-617 7.5 GBq every 6 weeks for up to 6 doses plus ipilimumab 3 mg/kg every 6 weeks x 4 doses and nivolumab 1 mg/kg every 3 weeks x 8 doses during induction, followed by nivolumab 480 mg every 4 weeks x 18 doses during maintenance or 177Lu-PSMA-617 alone. Key eligibility criteria include progression on prior androgen receptor pathway inhibitors, no more than one line of prior chemotherapy, significant PSMA avidity on 68GaPSMA-11 PET/CT (SUVmax ≥15 at one disease site and SUVmax ≥10 at measurable sites of disease > 10 mm), no FDG positive/PSMA negative disease and no contraindications to ICI. The primary endpoint is 12-month PSA progression-free survival (PSA-PFS). Secondary endpoints are PSA response rate, adverse events, radiographic-PFS, overall survival, objective response rate, duration of response and health-related quality of life. Correlative studies will evaluate exploratory biomarkers as potential predictive/prognostic factors. Assessments include clinical reviews and blood tests at baseline, then every 3-4 weeks; CT and bone scan at baseline, then every 12 weeks; 68Ga-PSMA-11 and 18F FDG PET/CTs at baseline; 68Ga-PSMA-11 PET/CT at week 24 and 177Lu-PSMA-617 SPECT/CT 24 hours after each 177Lu-PSMA-617 dose. Translational bloods include circulating tumour DNA and peripheral blood mononuclear cells collected at baseline, weeks 13 and 25, and at radiological progression. Optional fresh biopsies will be collected at baseline, weeks 3-5 and at progression. A sample size of 100 provides 90% power at the 10% level of significance to reject the null hypothesis (that 1 year PSA-PFS is 20%) if the alternative hypothesis is true (that 1 year PSA-PFS is 35%). Accrual as of the 11th of October 2022 is 23. Clinical trial information: NCT05150236 .

Performance of a blood-based liquid biopsy test to detect PSMA expression on circulating tumor cells in men with metastatic prostate cancer

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Background: PSMA-targeted radioligand therapy has dramatically improved clinical outcomes in men with mCRPC. A blood-based liquid biopsy assay to detect PSMA expression on circulating tumor cells (CTCs) could be helpful to optimize therapeutic decisions and identify patients most likely to benefit from PSMA-targeted therapies. Here we describe the development of this PSMA blood-based assay and the application of the single cell sequencing (SCS) pipeline to identify copy number alterations and further characterize heterogeneity in late-stage disease. Methods: A 4-color immunofluorescence (IF) assay was developed to detect PSMA expression on CTCs on the Epic Sciences liquid biopsy platform. CTCs were identified as DAPI+, cytokeratin (CK)+, and CD45- with appropriate cell morphology. Cells were plated onto glass slides and subjected to IF staining followed by CTC identification using a high throughput scanning platform with digital pathology machine learning algorithms. Cell line cells (LNCaP, PC3s, 22Rv1) of varying PSMA expression levels were spiked into normal blood (CLC/WBC; 1:10000) to create laboratory derived slides. Assay specificity, sensitivity, limit of detection (LOD), precision, and overall accuracy, as well as subcellular localization of biomarker expression were reported. Clinical validation was performed in a cohort of high-risk mCRPC patients (N=24) with previously demonstrated PSMA expression by tissue biopsy, utilizing 3ml of blood. Additionally, a subset of CTCs (36 cells from 11 patients) underwent single-cell low-pass whole genome sequencing to identify copy number alterations. Results: The PSMA CTC assay (Epic Sciences) achieved analytical specificity, sensitivity, and overall accuracy of over 99%. Precision was evaluated using intra-class correlation (ICC) (0.98). The assay showed an LOD of 1 CLC/technical replicate. PSMA expression was specific to staining outside the nucleus and distinguished from CK cytoplasmic staining. Analysis of 24 mCRPC samples revealed that 21/24 (88%) had at least one conventional CTC/mL (range: 0-30 CTCs/mL), of which 16/21 (76%) were PSMA positive (range: 0-27 CTCs/mL) with considerable tumor heterogeneity. 36 sequenced CTCs (N=11 pts) exhibited genomic heterogeneity and frequent AR (3/11), MYC (7/11), and MYCN (5/11) gains or losses of PTEN (4/11), TP53 (7/11), BRCA2 (5/11), CHD1 (6/11), and/or RB1(5/11 pts). Conclusions: The PSMA CTC assay analytical results firmly support its feasibility to detect PSMA expression in CTCs from mCRPC patient samples. The assay demonstrates high sensitivity, specificity, and overall accuracy. Many ongoing trials are designed to target PSMA-positive tumors, positioning this assay as a robust research tool to identify and longitudinally monitor PSMA expression and explore heterogeneity, response, and resistance in these patient populations.

Impact of run-in treatment with abiraterone acetate and prednisone (AAP) in the MAGNITUDE study of niraparib (NIRA) and AAP in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) gene alterations

172

Background: NIRA/AAP significantly improved outcomes in pts with mCRPC and HRR gene alterations, particularly in BRCA, in the phase 3 MAGNITUDE study. As a practical measure, pts were permitted to receive up to 4 mos of AAP (in 1L mCRPC) prior to randomization to allow time for genomic testing. We evaluated the impact of AAP run-in treatment on the efficacy of NIRA/AAP. Methods: 423 pts with mCRPC and HRR gene alterations were randomized 1:1 to receive NIRA/AAP or placebo (PBO)/AAP. At the prespecified second interim analysis, a sensitivity analysis based on the duration of AAP run-in was conducted. Pts with BRCA alterations were also analyzed separately. Results: Median duration of prior AAP treatment received was 1.9 (range, 0.3–4.1) mos. Pts receiving AAP ≤2 mos had similar benefit (radiographic progression-free survival [rPFS] hazard ratio [HR], 0.69 [95% confidence interval [CI], 0.36-1.30]; time to cytotoxic chemotherapy [TCC] HR, 0.52 [95% CI, 0.24-1.11]; time to symptomatic progression [TSP] HR, 0.32 [95% CI, 0.13-0.79]; Table) to pts not receiving any prior AAP. rPFS benefit was not demonstrated in pts who had previously received AAP >2 – 4 mos: HR, 1.47 (95% CI, 0.66-3.30). Findings were consistent in the BRCA population. Conclusions: Pts receiving a short run-in (≤2 mos) of AAP alone obtained similar benefit from NIRA/AAP as those who received both NIRA/AAP together for initial treatment of mCRPC. While interpretation of data is limited by the small sample size and event numbers, for pts where NIRA/AAP is being considered as therapy, AAP may be initiated during HRR testing and combination treatment should be initiated expeditiously once HRR positivity is established to attain maximal treatment benefit. Clinical trial information: NCT03748641 . [Table: see text]

Heterogeneity of canonical prostate cancer markers across lesions in metastatic castration-resistant prostate cancer

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Background: Metastatic castration-resistant prostate cancers (mCRPC) show a diversity of clinical responses and phenotypes, suggesting molecular heterogeneity. Understanding molecular phenotypes is critical for patient stratification and selection of therapeutic targets. Treatment with androgen receptor (AR) pathway inhibitors are thought to drive AR-negative disease and the emergence of neuroendocrine lineages. There are several emerging biomarkers for mCRPC, including novel targets, such as PSMA and STEAP1, and markers of neuroendocrine and aggressive disease, such as INSM1, DLL3, and loss of p53, RB1 and PTEN. Our understanding of the co-expression of such biomarkers across multiple metastatic sites is currently limited. This study aimed to determine biomarker expression in multiple anatomical sites within individual mCRPC patients. Methods: Through the rapid-autopsy CASCADE program at the Peter MacCallum Cancer Centre, tissue was obtained from 5-14 tumor sites from 12 individual mCRPC patients yielding samples from a total of 110 tumor sites (8 primary and 102 metastatic). Ten patients were diagnosed with prostate adenocarcinoma (89 sites), and 2 patients with neuroendocrine histopathology in all sites (21 sites). Tissue was stained for AR, PSMA, STEAP1, INSM1, DLL3 p53, RB1 and PTEN by immunohistochemistry (IHC). Serial sections were reviewed and scored by a pathologist. IHC results were corroborated with genetic information derived from DNA sequencing. Results: In the adenocarcinoma cohort, on average 77% of sites of individual patients had AR expression, suggesting intra-patient heterogeneity. Co-expression of AR and PSMA was common (55/89 sites), but 6/10 adenocarcinoma patients had 1 to 6 PSMA+AR- lesions. Co-expression of PSMA and STEAP1 was also common in adenocarcinoma patients (60/89 sites), although 8/10 patients had 1 to 2 PSMA-STEAP1+ lesions, and 7 patients had 1 to 3 PSMA+STEAP1- lesions. Expression of INSM1 and DLL3 was mostly seen in the 2 patients (20/21 sites) with neuroendocrine prostate cancer. In contrast, only 2 INSM1+DLL3+ tumor sites in liver and 1 INSM1-DLL3+ prostate cancer sample were detected in the adenocarcinoma cohort. Of the 110 sites, p53 loss was observed in 9, RB1 loss in 30 and PTEN loss in 25 sites. Of these, 8/9, 14/30 and 8/25 occurred in INSM1+DLL3+ sites, suggesting that loss of these markers does not always correlate with INSM1 and DLL3 expression. Conclusions: While AR, PSMA and STEAP1 expression are frequently detected in a single site of disease, this co-expression is not consistent across all sites. In this dataset, INSM1 and DLL3 expression was almost exclusively confined to neuroendocrine prostate cancer. Loss of RB1 and PTEN often occurs without INSM1 and DLL3 expression. Understanding differential biomarker expression in mCRPC may guide future targeted treatments and warrants further research.

Efficacy of systemic therapy following [177Lu] Lu-PSMA in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

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Background: [177Lu]Lu-PSMA (LuPSMA) is currently FDA-approved for use in the post-taxane, post-antiandrogen setting in pts with mCRPC. Little is known about the efficacy of treatment in pts with subsequent progression after LuPSMA. In this single-centre retrospective analysis, we evaluated efficacy of first subsequent therapy following LuPSMA. Methods: 234 mCRPC pts who received LuPSMA at the Peter MacCallum Cancer Centre from 2015-2022 were analysed. Pts were excluded if they did not receive any subsequent treatment (n=136), if they received the initial course of LuPSMA in combination with another therapy (n=10), or if insufficient follow-up data were available (n=15).Retreatment withLuPSMA was considered a subsequent line of therapy. Data collected included 50% PSA response rate (PSA-RR), PSA-progression free survival (PSA-PFS) and overall survival (OS). Survival outcomes were calculated using Kaplan-Meier analysis. Results: Of 73 evaluable pts, 32 were retreated with LuPSMA (median 2 cycles); and 41 commenced a new line of systemic therapy. In the LuPSMA retreatment group, the PSA-RR was 44%, median PSA-PFS was 3.8 months and median OS 14.8 months. In pts who changed to a new line of treatment, cabazitaxel was the most commonly prescribed therapy (n=25), followed by docetaxel (n=7), and single-agent carboplatin (n=4), in addition to carboplatin/etoposide, mitoxantrone, olaparib, capecitabine and a clinical trial (n=1 for each). PSA-RR was 12%, median PSA-PFS was 3.5 months and median OS 6.6 months. Conclusions: This retrospective data demonstrates that retreatment with LuPSMA is associated with benefit, though this is reduced compared to initial treatment. In our cohort of pts who commenced a new line of therapy, most were not suitable for retreatment with LuPSMA, potentially reflecting de-differentiated and more aggressive disease phenotypes. In those not suitable for LuPSMA retreatment, other systemic therapy appears to have limited benefit, highlighting the lack of effective salvage options and raising questions about treatment sequencing. [Table: see text]

Niraparib (NIRA) with abiraterone acetate and prednisone (AAP) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) gene alterations: Second interim analysis (IA2) of MAGNITUDE

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Background: In the primary analysis of the phase 3 MAGNITUDE study, NIRA/AAP significantly improved outcomes in pts with mCRPC and HRR gene alterations. Here, we report results from IA2 of secondary endpoints in MAGNITUDE. Methods: 423 eligible pts with mCRPC and HRR alterations (HRR+ cohort) were randomized 1:1 to receive NIRA/AAP (n = 212) or placebo (PBO)/AAP (n = 211). At the prespecified IA2, secondary endpoints (time to cytotoxic chemotherapy [TCC], time to symptomatic progression [TSP], overall survival [OS]) were formally assessed and the primary rPFS endpoint was updated in the HRR+ cohort, with sensitivity analysis performed for the subgroup of pts with BRCA alterations. Results: Updated descriptive rPFS results at IA2 (cutoff: June 17, 2022) were consistent with the primary analysis in the HRR+ cohort. In the BRCA subgroup, NIRA/AAP extended median rPFS to 19.5 mos vs 10.9 mos with PBO/AAP. NIRA/AAP led to statistically significant benefit in TSP in the HRR+ cohort with consistent benefit in the BRCA subgroup. Continued consistent improvement of TCC was seen with NIRA/AAP in the HRR+ cohort and in the BRCA subgroup. There was a trend towards improved OS with NIRA/AAP in the BRCA subgroup in the primary stratified analysis and the multivariate analysis (MVA), accounting for imbalances in key baseline characteristics. BRCA pts treated with NIRA/AAP experienced delayed time to worst pain intensity (HR, 0.70; 95% CI, 0.44, 1.12; nominal P = 0.1338) and pain interference (HR, 0.67; 95% CI, 0.40, 1.12; nominal P = 0.1275) compared to PBO/AAP. The safety profile at IA2 was consistent with that of the primary analysis, with no new safety signals observed. Conclusions: With 26.8 months of median follow-up, there was a statistically significant and meaningful clinical benefit in TSP and meaningful clinical benefit in TCC. Additionally, updated rPFS results from MAGNITUDE IA2 were consistent with the primary analysis; OS benefit was not conclusive due to immaturity and will be followed through to final analysis. Taken together, these data continue to support the use of NIRA/AAP in pts with mCRPC and BRCA alterations or select other HRR gene alterations. Clinical trial information: NCT03748641 . [Table: see text]

Impact of immune checkpoint inhibitors and targeted therapy on health-related quality of life of people with stage III and IV melanoma: a mixed-methods systematic review

BACKGROUND

Immune checkpoint inhibitors (ICI) and targeted therapies (TT) have significantly improved disease control and survival in people with stage III and IV cutaneous melanoma. Understanding the impact of therapy on health-related quality of life (HRQL) is vital for treatment decision-making and determining targets for supportive care intervention. We conducted a mixed-methods systematic review to synthesise the impact of ICIs and TT on all domains of HRQL in these populations.

METHODS

A systematic literature search was conducted in April 2022 on MEDLINE, PsycINFO, Embase and the Cochrane Central Register of Controlled Trials. Quantitative and qualitative data relevant to the review question were extracted and synthesised in tables according to setting (adjuvant versus metastatic), treatment type (ICI versus TT) and HRQL issue.

RESULTS

Twenty-eight papers describing 27 studies were included: 15 randomised controlled trials (RCTs), four cohort studies, four single arm cross-sectional studies, two qualitative studies, one case control study and one mixed-methods study. In four studies of people with resected stage III melanoma, adjuvant pembrolizumab and dabrafenib-trametinib did not clinically or statistically change HRQL compared to baseline. In 17 studies of people with unresectable stage III/IV melanoma, inconsistencies in the impact of ICI on symptoms, functioning and overall HRQL were noted across different study designs. TT was associated with improvements in symptoms, functioning and HRQL across six studies.

CONCLUSION

This review highlights the key physical, psychological and social issues experienced by people with stage III and IV melanoma treated with ICI and TT. Inconsistencies in the impact of ICI on HRQL were observed in different study designs. This highlights the need for treatment-specific patient-reported outcome measures for determining the impact of these therapies on HRQL and real-world data to inform treatment decision-making and appropriate supportive care interventions.

Adjuvant Therapy of Nivolumab Combined With Ipilimumab Versus Nivolumab Alone in Patients With Resected Stage IIIB-D or Stage IV Melanoma (CheckMate 915)

PURPOSE

Ipilimumab and nivolumab have each shown treatment benefit for high-risk resected melanoma. The phase III CheckMate 915 trial evaluated adjuvant nivolumab plus ipilimumab versus nivolumab alone in patients with resected stage IIIB-D or IV melanoma.

PATIENTS AND METHODS

In this randomized, double-blind, phase III trial, 1,833 patients received nivolumab 240 mg once every 2 weeks plus ipilimumab 1 mg/kg once every 6 weeks (916 patients) or nivolumab 480 mg once every 4 weeks (917 patients) for ≤ 1 year. After random assignment, patients were stratified by tumor programmed death ligand 1 (PD-L1) expression and stage. Dual primary end points were recurrence-free survival (RFS) in randomly assigned patients and in the tumor PD-L1 expression-level < 1% subgroup.

RESULTS

At a minimum follow-up of approximately 23.7 months, there was no significant difference between treatment groups for RFS in the all-randomly assigned patient population (hazard ratio, 0.92; 95% CI, 0.77 to 1.09; P = .269) or in patients with PD-L1 expression < 1% (hazard ratio, 0.91; 95% CI, 0.73 to 1.14). In all patients, 24-month RFS rates were 64.6% (combination) and 63.2% (nivolumab). Treatment-related grade 3 or 4 adverse events were reported in 32.6% of patients in the combination group and 12.8% in the nivolumab group. Treatment-related deaths were reported in 0.4% of patients in the combination group and in no nivolumab-treated patients.

CONCLUSION

Nivolumab 240 mg once every 2 weeks plus ipilimumab 1 mg/kg once every 6 weeks did not improve RFS versus nivolumab 480 mg once every 4 weeks in patients with stage IIIB-D or stage IV melanoma. Nivolumab showed efficacy consistent with previous adjuvant studies in a population resembling current practice using American Joint Committee on Cancer eighth edition, reaffirming nivolumab as a standard of care for melanoma adjuvant treatment.

Safety Profile of Ipatasertib Plus Abiraterone vs Placebo Plus Abiraterone in Metastatic Castration-resistant Prostate Cancer

PURPOSE

Adding ipatasertib to abiraterone and prednisone/prednisolone significantly improved radiographic progression-free survival for patients with metastatic castration-resistant prostate cancer (mCRPC) with PTEN-loss tumours by immunohistochemistry in the IPATential150 trial (NCT03072238). Here we characterise the safety of these agents in subpopulations and assess manageability of key adverse events (AEs).

MATERIALS AND METHODS

In this randomised, double-blind, phase 3 trial, patients with previously untreated asymptomatic or mildly symptomatic mCRPC were randomised 1:1 to receive ipatasertib-abiraterone or placebo-abiraterone (all with prednisone/prednisolone). AEs were analysed, focusing on key AEs of diarrhoea, hyperglycaemia, rash and transaminase increased.

RESULTS

1097 patients received study medication and were assessed for safety (47% with PTEN-loss tumours by immunohistochemistry and 20% were Asian). Ipatasertib was associated with increased Grade 3/4 AEs and AEs leading to treatment discontinuation vs placebo. The rate of discontinuation of ipatasertib was 18% in patients with PTEN-loss and 21% overall. The frequencies of all-grade, Grade 3/4 and serious AEs were similar between the PTEN-loss and overall populations. Diarrhoea, hyperglycaemia, rash and transaminase elevation were more frequent in ipatasertib-treated patients, appearing rapidly after treatment initiation (median onset: 8-43 days for ipatasertib arm and 56-104 days for placebo). The ipatasertib discontinuation rate was 32% and 18% in Asian and non-Asian patients, respectively, despite similar baseline characteristics and Grade 3/4 AE frequencies between groups.

CONCLUSIONS

Ipatasertib plus abiraterone had an overall tolerable safety profile consistent with known toxicities. More AEs leading to drug discontinuation were observed with ipatasertib than placebo, but incidence would likely be lessened with prophylactic measures.

Combination of the STING Agonist MIW815 (ADU-S100) and PD-1 Inhibitor Spartalizumab in Advanced/Metastatic Solid Tumors or Lymphomas: An Open-Label, Multicenter, Phase Ib Study

PURPOSE

The stimulator of IFN genes (STING) is a transmembrane protein that plays a role in the immune response to tumors. Single-agent STING agonist MIW815 (ADU-S100) has demonstrated immune activation but limited antitumor activity. This phase Ib, multicenter, dose-escalation study assessed the safety and tolerability of MIW815 plus spartalizumab (PDR001), a humanized IgG4 antibody against PD-1, in 106 patients with advanced solid tumors or lymphomas.

PATIENTS AND METHODS

Patients were treated with weekly intratumoral injections of MIW815 (50-3,200 μg) on a 3-weeks-on/1-week-off schedule or once every 4 weeks, plus a fixed dose of spartalizumab (400 mg) intravenously every 4 weeks.

RESULTS

Common adverse events were pyrexia (n = 23; 22%), injection site pain (n = 21; 20%), and diarrhea (n = 12; 11%). Overall response rate was 10.4%. The MTD was not reached. Pharmacodynamic biomarker analysis demonstrated on-target activity.

CONCLUSIONS

The combination of MIW815 and spartalizumab was well tolerated in patients with advanced/metastatic cancers, including in patients with anti-PD-1 refractory disease. Minimal antitumor responses were seen.

Effect of Coenzyme Q10 Supplementation on Sarcopenia, Frailty, and Falls: A Scoping Review

Coenzyme Q10 (CoQ10) is well-known for its antioxidant effects and has been highlighted in research related to aging and many age-related conditions. However, there is limited research on the benefit of CoQ10 supplementation in conditions impacting the physical robustness of older adults, such as sarcopenia, frailty, falls and osteoporosis. This scoping review identified and summarized 4 studies that assessed the effects of exogenous CoQ10 on outcomes relating to sarcopenia, frailty, and falls. Results of the studies showed statistically significant improvements in a variety of physical robustness related outcomes, however several limitations of these studies prevent conclusive recommendations from being drawn regarding the benefit of CoQ10 supplementation in these conditions. A well-designed randomized control trial assessing the benefit of CoQ10 supplementation on clinically relevant outcomes related to sarcopenia, frailty, and falls may be warranted.

Neurological adverse effects associated with anti-PD1 antibodies alone or in combination with ipilimumab: a multicenter case series

Anti-programmed cell death protein 1 (PD1) antibodies, pembrolizumab and nivolumab, alone or in combination with ipilimumab, have become standard treatment for melanoma and multiple other malignancies. Neurological adverse effects are rare and have not been well characterized to date. Patients who developed neurological adverse effects while being treated with PD1, alone or in combination with ipilimumab, were retrospectively identified from 10 cancer centers. Fifty-eight patients were included, and the median time from treatment initiation to development of neurological adverse effects was 7 weeks (range, 1-86.5 weeks). Thirty-seven (64%) toxicities affected the peripheral nervous system. Fifty (86%) patients were treated with corticosteroids, with 22 (37%) patients requiring further immunomodulation including intravenous immunoglobulin (16), plasmapheresis (7), mycophenolate mofetil (4), cyclophosphamide (1), and rituximab (1). Twenty-seven (46%) had a complete resolution of their neurological symptoms, and two (4%) patients died secondary to complications from their neurological adverse effects. The response rate of the cancer to immunotherapy was 78%, and the median progression free survival was not reached. Neurological adverse effects can occur with PD1 treatment, do not appear to impact treatment response, but may be irreversible or worsen in some patients. Management may require immunomodulation beyond corticosteroids.

Clinical Application of Poly(ADP-ribose) Polymerase (PARP) Inhibitors in Prostate Cancer

Approximately a quarter of men with metastatic castrate resistant prostate cancer (mCRPC) have alterations in homologous recombination repair (HRR). These patients exhibit enhanced sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors. Leveraging the synthetic lethality between PARP inhibition and HRR deficiency, studies have established marked clinical benefit and a survival advantage from PARP inhibitors (PARPi) in mCRPC, most notably in cancers with BRCA1/2 alterations. The role of PARPi is evolving beyond patients with HRR alterations, with studies increasingly focused on exploiting synergistic effects from combination therapeutics. Strategies combining PARP inhibitors with androgen receptor pathway inhibitors, radiation, radioligand therapy, chemotherapy and immunotherapy demonstrate potential additional benefits in mCRPC and these approaches are rapidly moving into the metastatic hormone sensitive treatment paradigm. In this review we summarise the development and expanding role of PARPi in prostate cancer including biomarkers of response, the relationship between the androgen receptor and PARP, evidence for combination therapeutics and the future directions of PARPi in precision medicine for prostate cancer.

Five-Year Analysis of Adjuvant Pembrolizumab or Placebo in Stage III Melanoma

Pembrolizumab or Placebo in Stage III MelanomaPatients with stage III melanoma randomly received adjuvant pembrolizumab or placebo. Five-year recurrence-free survival was 55.4% (95% CI, 50.8 to 59.8) versus 38.3% (33.9 to 42.7) and 5-year metastasis-free survival was 60.6% (56.0 to 64.9) versus 44.5% (39.9 to 48.9) for adjuvant pembrolizumab and placebo, respectively. No new safety signals were associated with adjuvant pembrolizumab.

Modelling aggressive prostate cancers of young men in immune-competent mice, driven by isogenic Trp53 alterations and Pten loss

Understanding prostate cancer onset and progression in order to rationally treat this disease has been critically limited by a dire lack of relevant pre-clinical animal models. We have generated a set of genetically engineered mice that mimic human prostate cancer, initiated from the gland epithelia. We chose driver gene mutations that are specifically relevant to cancers of young men, where aggressive disease poses accentuated survival risks. An outstanding advantage of our models are their intact repertoires of immune cells. These mice provide invaluable insight into the importance of immune responses in prostate cancer and offer scope for studying treatments, including immunotherapies. Our prostate cancer models strongly support the role of tumour suppressor p53 in functioning to critically restrain the emergence of cancer pathways that drive cell cycle progression; alter metabolism and vasculature to fuel tumour growth; and mediate epithelial to mesenchymal-transition, as vital to invasion. Importantly, we also discovered that the type of p53 alteration dictates the specific immune cell profiles most significantly disrupted, in a temporal manner, with ramifications for disease progression. These new orthotopic mouse models demonstrate that each of the isogenic hotspot p53 amino acid mutations studied (R172H and R245W, the mouse equivalents of human R175H and R248W respectively), drive unique cellular changes affecting pathways of proliferation and immunity. Our findings support the hypothesis that individual p53 mutations confer their own particular oncogenic gain of function in prostate cancer.