ATLANTIS: a randomised multi-arm phase II biomarker-directed umbrella screening trial of maintenance targeted therapy after chemotherapy in patients with advanced or metastatic urothelial cancer

Similar genetic profile in early and late stage urothelial tract cancer

INTRODUCTION

Urothelial tract cancer (UTC) ranks as the tenth most prevalent cancer and holds the seventh position in terms of mortality worldwide. Despite its prevalence and mortality ranking, there are still gaps in the knowledge of the mutational landscape in patients with advanced disease who have limited therapeutic options after multiple lines of prior treatment. This study compares the genomic and transcriptomic landscape, and targeted treatment options between metastatic UTC (mUTC) patients treated with multiple lines of therapy compared to newly diagnosed, untreated Muscle Invasive Bladder Cancer (MIBC).

METHODS

We compared genomic and clinical data from two cohorts: mUTC patients who received multiple lines of therapy and were referred to the Copenhagen Prospective Personalized Oncology (CoPPO) project at Rigshospitalet, University of Copenhagen. Data for MIBC UTC patients were acquired from the Cancer Genome Atlas Bladder Cancer (TCGA BLCA) cohort. Biopsies in CoPPO were performed at the time of enrollment. 523 highly important cancer-related genes (TrueSight Oncology-500 targeted sequencing panel) were used from both cohorts for comparative analysis. Analyses included RNA count data to compare predicted molecular subtypes in each cohort separately.

RESULTS

Patients from the CoPPO cohort had a lower median age at first-line treatment than the TCGA BLCA cohort, with no significant gender disparity. The predominant histology was urothelial cell carcinoma in both cohorts. Genomic analysis revealed no significant difference between the top mutated genes in the two cohorts, specifically looking into DNA damage repair genes. Molecular subtyping indicated a higher frequency of neuroendocrine differentiation in the CoPPO cohort. 13% of patients in the CoPPO cohort received targeted therapy based on genomic findings, and 16% received non-targeted treatment, totaling 29% receiving CoPPO treatment (9 patients). The remaining 71% received best supportive care. Kaplan-Meier analysis showed a non-significant survival benefit for the intervention group in the CoPPO cohort.

CONCLUSION

When focusing on 523 highly relevant cancer genes, the mutational profile of mUTC patients who have undergone numerous treatment lines resembles that of newly diagnosed MIBC. These alterations can be targeted, indicating the potential advantage of early genomic testing for personalized treatment within clinical trials.

PARP Inhibitors for Metastatic Urothelial Carcinoma: A Systematic Review of Efficacy and Safety

BACKGROUND

Poly (ADP-ribose) polymerase (PARP) inhibitors have activity in various cancers. Metastatic urothelial carcinoma (MUC) is platinum sensitive and a subset harbour DNA repair gene alterations.

OBJECTIVE

To assess evidence for efficacy and safety of PARP inhibition for MUC.

METHODS

This systematic review included randomised clinical trials (RCTs) evaluating PARP inhibitors as monotherapy, or in therapeutic combinations, compared to relevant comparators or best supportive care. The primary endpoint was progression free survival (PFS). We searched MEDLINE (Ovid), EMBASE, ClinicalTrials.gov and Cochrane Central Register of Controlled Trials from March 2013 to March 2023. Each study was appraised using the Cochrane Risk of Bias 2 Tool. Study results were synthesised descriptively. Registration: PROSPERO CRD42023403145.

RESULTS

From 247 identified reports, we included three phase 2 RCTs including 252 patients. Two RCTs assessed PARP inhibition in unselected patient groups (one first line platinum ineligible, one post chemotherapy maintenance) and found no evidence of efficacy. All three RCTs assessed subgroups defined by biomarker selection for somatic DNA repair defects. Two of these identified PFS benefit with PARP inhibition compared to a relevant comparator (one first line in combination with immunotherapy, one maintenance monotherapy). Safety outcomes were consistent with prior experience of PARP inhibitors. The risk of bias across the outcomes was generally low.

CONCLUSIONS

PARP inhibitors lack efficacy for unselected MUC patients. Phase 2 RCTs support further investigation of PARP inhibition within biomarker-selected patient subsets. The optimal biomarker is not yet determined. Limitations in the current evidence relate to small sample sizes and low statistical power.

FOCUS4 biomarker laboratories: from the benefits to the practical and logistical issues faced during 6 years of centralised testing

AIMS

FOCUS4 was a phase II/III umbrella trial, recruiting patients with advanced or metastatic colorectal cancer, between 2014 and 2020. Molecular profiling of patients' formalin-fixed, paraffin-embedded tumour blocks was undertaken at two centralised biomarker laboratories (Leeds and Cardiff), and the results fed directly to the Medical Research Council Clinical Trials Unit, and used for subsequent randomisation. Here the laboratories discuss their experiences.

METHODS

Following successful tumour content assessment, blocks were sectioned for DNA extraction and immunohistochemistry (IHC). Pyrosequencing was initially used to determine tumour mutation status (KRAS, NRAS, BRAF and PIK3CA), then from 2018 onwards, next-generation sequencing was employed to allow the inclusion of TP53. Protein expression of MLH1, MSH2, MSH6, PMS2 and pTEN was determined by IHC. An interlaboratory comparison programme was initiated, allowing sample exchanges, to ensure continued assay robustness.

RESULTS

1291 tumour samples were successfully analysed. Assay failure rates were very low; 1.9%-3.3% for DNA sequencing and 0.9%-1.3% for IHC. Concordance rates of >98% were seen for the interlaboratory comparisons, where a result was obtained by both laboratories.

CONCLUSIONS

Practical and logistical problems were identified, including poor sample quality and difficulties with sample anonymisation. The often last-minute receipt of a sample for testing and a lack of integration with National Health Service mutation analysis services were challenging. The laboratories benefitted from both pretrial validations and interlaboratory comparisons, resulting in robust assay development and provided confidence during the implementation of new sequencing technologies. We conclude that our centralised approach to biomarker testing in FOCUS4 was effective and successful.

Stranger Things: New Roles and Opportunities for Androgen Receptor in Oncology Beyond Prostate Cancer

The androgen receptor (AR) is one of the oldest therapeutic targets in oncology and continues to dominate the treatment landscape for advanced prostate cancer, where nearly all treatment regimens include some form of AR modulation. In this regard, AR remains the central driver of prostate cancer cell biology. Emerging preclinical and clinical data implicate key roles for AR in additional cancer types, thereby expanding the importance of this drug target beyond prostate cancer. In this mini-review, new roles for AR in other cancer types are discussed as well as their potential for treatment with AR-targeted agents. Our understanding of these additional functions for AR in oncology expand this receptor's potential as a therapeutic target and will help guide the development of new treatment approaches.

A Randomized, Double-Blind, Biomarker-Selected, Phase II Clinical Trial of Maintenance Poly ADP-Ribose Polymerase Inhibition With Rucaparib Following Chemotherapy for Metastatic Urothelial Carcinoma

PURPOSE

A DNA repair deficiency (DRD) phenotype exists within a subset of metastatic urothelial carcinomas (mUC) predicting benefit from platinum-based chemotherapy. We tested switch maintenance therapy with the poly ADP-ribose polymerase inhibitor rucaparib, following chemotherapy, for DRD biomarker-positive mUC.

METHODS

DRD biomarker-positive mUC patients, within 10 weeks of chemotherapy, and without cancer progression, were randomly assigned (1:1) to maintenance rucaparib 600 mg twice a day orally, or placebo, until disease progression. The primary end point was progression-free survival (PFS). Statistical analysis targeted a hazard ratio of 0.5 with a 20% one-sided α for this signal-seeking trial. PFS (RECIST 1.1) was compared between trial arms, by intention to treat, within a Cox model.

RESULTS

Out of 248 patients, 74 (29.8%) were DRD biomarker-positive and 40 were randomly assigned. A total of 12 (60%) and 20 (100%) PFS events occurred in the rucaparib and placebo arms, respectively (median follow-up was 94.6 weeks in those still alive). Median PFS was 35.3 weeks (80% CI, 11.7 to 35.6) with rucaparib and 15.1 weeks (80% CI, 11.9 to 22.6) with placebo (hazard ratio, 0.53; 80% CI, 0.30 to 0.92; one-sided P = .07). In the safety population (n = 39) treatment-related adverse events were mostly low grade. Patients received a median duration of 10 rucaparib or six placebo cycles on treatment. Treatment-related adverse events (all grades) of fatigue (63.2% v 30.0%), nausea (36.8% v 5.0%), rash (21.1% v 0%), and raised alanine aminotransferase (57.9% v 10%) were more common with rucaparib.

CONCLUSION

Maintenance rucaparib, following platinum-based chemotherapy, extended PFS in DRD biomarker-selected patients with mUC and was tolerable. Further investigation of poly ADP-ribose polymerase inhibition in selected patients with mUC is warranted.

Switch Maintenance Therapy for Metastatic Urothelial Carcinoma

INTRODUCTION

While switch maintenance therapy is being increasingly investigated in solid tumors, it is a standard in only a few. We conducted a systematic review on switch maintenance therapy for metastatic urothelial carcinoma.

EVIDENCE ACQUISITION

In this systematic review, we conducted a literature search in PubMed and Cochrane databases up to 2021, based on PRISMA statement guidelines. One hundred and fifty eight articles were identified and after a three-step selection process and six articles, using different agents were included in evidence synthesis. The primary end points were effect on overall survival, progression free survival, safety and tolerability.

EVIDENCE SYNTHESIS

In the pre-immunotherapy era, targeted therapies like sunitinib, lapatinib and vinflunine were studied as switch maintenance therapy in metastatic urothelial carcinoma but did not show any overall survival benefit. Use of anti-PD-1/PD-L1 agents have shown promise as switch maintenance therapy; pembrolizumab showed improvement in progression free survival in a phase 2 trial and avelumab showed improvement in overall survival and progression free survival in the phase 3 JAVELIN Bladder 100 trial.

CONCLUSION

Immunotherapy with anti-PD-1/PD-L1 agents has emerged as an effective switch maintenance strategy in patients with metastatic urothelial carcinoma. Intensification of the immunotherapy backbone in this setting can potentially further enhance outcomes. Emerging evidence shows a potential role of Poly (ADP-ribose) polymerase (PARP) inhibitors in this setting as well. Results from ongoing and planned studies will help us understand which switch maintenance approaches would be most effective for improving outcomes in metastatic urothelial carcinoma.

TALASUR trial: a single arm phase II trial assessing efficacy and safety of TALazoparib and Avelumab as maintenance therapy in platinum-Sensitive metastatic or locally advanced URothelial carcinoma

BACKGROUND

Urothelial carcinoma (UC) is the ninth most commonly diagnosed cancer worldwide, with a 3.8/1 male to female ratio. Platinum-based chemotherapy is the first line standard of care for fit patients with advanced UC. However, despite a response rate (RR) for approximately half of patients receiving standard chemotherapy, durable responses are rare (median progression-free progression (PFS) around 8 months). Recently, immune checkpoint inhibitors (ICI) have emerged as new therapeutic options. Among them, Avelumab, an anti-PD-L1 antibody, was assessed in maintenance treatment, demonstrating an overall survival improvement in the JAVELIN Bladder-100 phase III trial. These findings led to its approval as first line maintenance therapy for patients with locally advanced or metastatic UC who have not progressed on prior platinum-containing chemotherapy. However, disease progression as best response was noticed for 37% of patients under Avelumab as maintenance treatment. UC has targetable genomic alterations, including DNA damage repair (DDR) alterations. DDR deficiency is known to major sensitivity to both platinum-based chemotherapy and PD-1/PD-L1 blockade and the combination of ICI and PARP inhibitors showed promising results. It therefore warrants to assess the interest of combining ICI plus PARP inhibitors as maintenance treatment in UC patients.

METHODS

The TALASUR trial is a single-arm multicenter phase 2 study aiming to assess the antitumor activity of the combination of Avelumab with Talazoparib among patients with locally advanced/metastatic UC in maintenance therapy after platinum-based chemotherapy. The primary objective is to determine the efficacy of the combination, assessed through PFS. Secondary objectives are as follows: safety profile of the association, objective response, duration of tumoral response, disease control rate, time to subsequent therapy, quality of life. A blood and tumor collections will be also constituted. Patient will receive the combination therapy of daily oral Talazoparib (1 mg/day) and intra-venous Avelumab 800 mg on days 1 and 15, in a 28-day cycle. Fifty patients will be enrolled.

DISCUSSION

Talazoparib with Avelumab combination may have additive activity when administrated jointly. We hypothesize that combination will increase the antitumor activity in UC first line maintenance setting with an acceptable safety profile.

TRIAL REGISTRATION

NCT04678362, registered December 21, 2020.

PROTOCOL VERSION

 Version 1.3 dated from 2020 09 11.

Design and analysis of umbrella trials: Where do we stand?

Background

The efficiencies that master protocol designs can bring to modern drug development have seen their increased utilization in oncology. Growing interest has also resulted in their consideration in non-oncology settings. Umbrella trials are one class of master protocol design that evaluates multiple targeted therapies in a single disease setting. Despite the existence of several reviews of master protocols, the statistical considerations of umbrella trials have received more limited attention.

Methods

We conduct a systematic review of the literature on umbrella trials, examining both the statistical methods that are available for their design and analysis, and also their use in practice. We pay particular attention to considerations for umbrella designs applied outside of oncology.

Findings

We identified 38 umbrella trials. To date, most umbrella trials have been conducted in early phase settings (73.7%, 28/38) and in oncology (92.1%, 35/38). The quality of statistical information available about conducted umbrella trials to date is poor; for example, it was impossible to ascertain how sample size was determined in the majority of trials (55.3%, 21/38). The literature on statistical methods for umbrella trials is currently sparse.

Conclusions

Umbrella trials have potentially great utility to expedite drug development, including outside of oncology. However, to enable lessons to be effectively learned from early use of such designs, there is a need for higher-quality reporting of umbrella trials. Furthermore, if the potential of umbrella trials is to be realized, further methodological research is required.