Cancer genomics: the challenge of drug accessibility

Clinical Impact of Comprehensive Molecular Profiling in Adolescents and Young Adults with Sarcoma

Sarcomas are a heterogenous group of tumours that commonly carry poor prognosis with limited therapeutic options. Adolescents and young adults (AYAs) with sarcoma are a unique and understudied patient population that have only achieved modest survival gains compared to other groups. We present our institutional experience of AYAs with sarcoma who underwent comprehensive molecular profiling (CMP) via either large-panel targeted DNA sequencing or whole genome and transcriptome sequencing and evaluated the feasibility and clinical impact of this approach. Genomic variants detected were determined to be clinically relevant and actionable following evaluation by the Molecular Tumour Board. Clinicians provided feedback regarding the utility of testing three months after reporting. Twenty-five patients who were recruited for CMP are included in this analysis. The median time from consent to final molecular report was 45 days (interquartile range: 37-57). Potentially actionable variants were detected for 14 patients (56%), and new treatment recommendations were identified for 12 patients (48%). Pathogenic germline variants were identified in three patients (12%), and one patient had a change in diagnosis. The implementation of CMP for AYAs with sarcoma is clinically valuable, feasible, and should be increasingly integrated into routine clinical practice as technologies and turnaround times continue to improve.

Effects of volume-based procurement policy on the usage and expenditure of first-generation targeted drugs for non-small cell lung cancer with EGFR mutation in China: an interrupted time series study

OBJECTIVES

In December 2018, China launched national volume-based procurement (NVBP) to negotiate drug prices with manufacturers. Gefitinib was one of the 25 pilot drugs, which is used for treatment of non-small cell lung cancer. Lung cancer is the most common type of cancer in China and targeted drugs like gefitinib have been proven to provide clinical benefits to patients. This study aims to explore the impact of NVBP policy on the usage and expenditure of anticancer drugs.

METHODS

Gefitinib and alternative drugs (icotinib and erlotinib) were used as objects of study. Quarterly data from the China Hospital Pharmaceutical Audit database in 9454 hospitals in China were used for analysis. Descriptive analysis was conducted using purchase volume and expenditure as variables. Interrupted time-series (ITS) analysis was applied to further analyse the effect of NVBP policy on the medicines under study.

RESULTS

During the 12-month period before (2018Q2-2019Q1) and after (2019Q2-2020Q1) the NVBP policy, the total purchase volume of medicines rose from 4.48 million defined daily dose (DDD) to 7.02 million DDD, with an increase of 56.66%. Purchase volume of gefitinib and alternative drugs increased 100.61% and 14.88%, respectively. After the implementation of NVBP policy, procurement volume of alternative drugs decreased by 72 051 DDD (p value=0.044) and trend change decreased by 56 738 DDD (p value<0.01). The overall expenditure reduction was 14.7%, with the expenditure of gefitinib reducing by 38.47% and alternative drugs increasing by 10.70%. ITS analysis indicated statistically significant differences in level and trend changes for expenditure of total drugs and gefitinib.

CONCLUSIONS

The evidence provided in this study indicated that the implementation of NVBP policy was related to the expenditure reduction of the first generation of anti-EGFR lung cancer drugs. The policy effectively controlled the increase in expenditures for corresponding drugs while ensuring the use of drugs.

Access to Clinical Trials for Adolescents and Young Adults With Cancer: A Meta-Research Analysis

BACKGROUND

The 18-year-old age limit for inclusion in clinical trials constitutes a hurdle for adolescents and young adults (AYAs) with cancer. We analyzed the impact of this age barrier on the access of AYAs to cancer trials and novel therapies.

METHODS

ClinicalTrials.gov was searched to identify all the trials including patients with 10 malignancies relevant for AYAs (January 2007 to July 2018). The trials were categorized as pediatric (patients <18 y), adult (≥18 y), and transitional (including adult and pediatric patients). Transitional trials with a lower limit between 12 and 18 years and an upper limit younger than 40 years were considered AYA-specific.

RESULTS

Of 2764 identified trials, 2176 were included: 79% adult, 19% transitional, 2% pediatric. Five trials were AYA-specific. The proportion of academic trials was higher for transitional (69%; 288 of 421) than for adult trials (48%; 832 of 1718) (P < .0001). The total number of new trials increased over the years (156 in 2007; 228 in 2017); however, the number of transitional trials remained stable. The availability of trials increased with age, with a major increase at age 18 years: at age 17 years, 20% (442 of 2176) of trials were potentially accessible vs 95% (2075 of 2176) at 18 years. For trials investigating targeted therapies, this increase was 460% (197 trials available at age 17 years; 901 at 18 years) and for immunotherapies, 1200% (55 at age 17 years; 658 at 18 years).

CONCLUSIONS

AYAs have limited access to cancer trials and innovative therapies, with no improvement over the last decade. The 18-years-old age limit continues to be a major hurdle. Our findings are consistent with the internationally supported idea that age inclusion criteria in oncological trials should be changed.

Prospective analysis of 895 patients on a UK Genomics Review Board

BACKGROUND

The increasing frequency and complexity of cancer genomic profiling represents a challenge for the oncology community. Results from next-generation sequencing-based clinical tests require expert review to determine their clinical relevance and to ensure patients are stratified appropriately to established therapies or clinical trials.

METHODS

The Sarah Cannon Research Institute UK/UCL Genomics Review Board (GRB) was established in 2014 and represents a multidisciplinary team with expertise in molecular oncology, clinical trials, clinical cancer genetics and molecular pathology. Prospective data from this board were collated.

RESULTS

To date, 895 patients have been reviewed by the GRB, of whom 180 (20%) were referred for clinical trial screening and 62 (7%) received trial therapy. For a further 106, a clinical trial recommendation was given.

CONCLUSIONS

Numerous challenges are faced in implementing a GRB, including the identification of potential germline variants, the interpretation of variants of uncertain significance and consideration of the technical limitations of pathology material when interpreting results. These challenges are likely to be encountered with increasing frequency in routine practice. This GRB experience provides a model for the multidisciplinary review of molecular profiling data and for the linking of molecular analysis to clinical trial networks.

Effects of removing reimbursement restrictions on targeted therapy accessibility for non-small cell lung cancer treatment in Taiwan: an interrupted time series study

INTERVENTIONS

Targeted therapies have been proven to provide clinical benefits to patients with metastatic non-small cell lung cancer (NSCLC). Gefitinib was initially approved and reimbursed as a third-line therapy for patients with advanced NSCLC by the Taiwan National Health Insurance (NHI) in 2004; subsequently it became a second-line therapy (in 2007) and further a first-line therapy (in 2011) for patients with epidermal growth factor receptor mutation-positive advanced NSCLC. Another targeted therapy, erlotinib, was initially approved as a third-line therapy in 2007, and it became a second-line therapy in 2008.

OBJECTIVES

This study is aimed towards an exploration of the impacts of the Taiwan NHI reimbursement policies (removing reimbursement restrictions) related to accessibility of targeted therapies.

SETTING

We retrieved 2004-2013 claims data for all patients with lung cancer diagnoses from the NHI Research Database.

DESIGN AND OUTCOME MEASURES

Using an interrupted time series design and segmented regression, we estimated changes in the monthly prescribing rate by patient number and market shares by cost following each modification of the reimbursement policy for gefitinib and erlotinib for NSCLC treatment.

RESULTS

Totally 92 220 patients with NSCLC were identified. The prescribing rate of the targeted therapies increased by 15.58%, decreased by 10.98% and increased by 6.31% following the introduction of gefitinib as a second-line treatment in 2007, erlotinib as a second-line treatment in 2008 and gefitinib as as first line treatment in 2011, respectively. The average time to prescription reduced by 65.84% and 41.59% following coverage of erlotinib by insurance and gefitinib/erlotinib as second-line treatments in 2007-2008 and following gefitinib as the first-line treatment in 2011.

CONCLUSIONS

The changes in reimbursement policies had a significant impact on the accessibility of targeted therapies for NSCLC treatment. Removing reimbursement restrictions can significantly increase the level and the speed of drug accessibility.

Analysis of Circulating Tumor DNA and Clinical Correlates in Patients with Esophageal, Gastroesophageal Junction, and Gastric Adenocarcinoma

PURPOSE

Esophageal, gastroesophageal junction, and gastric adenocarcinoma (herein gastroesophageal adenocarcinomas) are associated with poor prognosis and limited systemic treatment options. To further understand the genomic landscape of gastroesophageal cancers and its clinical correlations, circulating tumor DNA (ctDNA) from patients' plasma was evaluated using next-generation sequencing (NGS).

EXPERIMENTAL DESIGN

We analyzed genomic alterations of 55 patients (mostly advanced disease; 9, surgically resectable) with gastroesophageal adenocarcinomas using clinical-grade NGS performed on plasma-derived ctDNA (54-73 gene panel). The test detects single-nucleotide variants, as well as copy number amplifications, fusions, and indels in selected genes.

RESULTS

Seventy-six percent of patients (42/55) had ≥1 genomic alteration [including variants of unknown significance (VUS)] and 69.1% (38/55) had ≥1 characterized alteration (excluding VUSs). The median number of alterations per patient was 2 (range, 0-15). TP53 (50.9%, 28/55), PIK3CA (16.4%, 9/55), ERBB2 (14.5%, 8/55), and KRAS (14.5%, 8/55) genes were most frequently affected characterized alterations. Thirty-one patients also had tissue NGS. Concordance between tissue and ctDNA ranged from 61.3% (TP53 alterations) to 87.1% (KRAS alterations). ERBB2 alterations were significantly associated with poor overall survival (HR, 14.06; 95% confidence interval, 2.44-81.03; P = 0.003 multivariate analysis). Among patients with ≥1 alteration, no 2 patients had identical molecular portfolios. All patients with ≥1 characterized alteration had theoretically targetable alterations by an FDA-approved agent (on- or off-label). Illustrative case treated with cognate agent is presented.

CONCLUSIONS

Evaluation of ctDNA by NGS among patients with gastroesophageal adenocarcinoma is feasible. Patients harbored heterogeneous patterns of genomics, with most having alterations that are potentially pharmacologically tractable.

Long-term exposure to MST-312 leads to telomerase reverse transcriptase overexpression in MCF-7 breast cancer cells

Telomerase is an enzyme responsible for telomere maintenance in almost all human cancer cells, but generally not expressed in somatic ones. Therefore, antitelomerase therapy is a potentially revolutionary therapeutic strategy, and the antitumor activity of telomerase inhibitors (TI) has been studied extensively recently, mainly for breast cancer. However, the effects expected from treatment with TI will appear only after many cell divisions, but the effects of this long-term approach are unknown. In this work, the consequences of 3120 h exposure of human breast cancer cells to TI MST-312 were investigated. MCF-7 cells were treated with MST-312 at a subtoxic concentration for a long time, and then cell morphology, viability, senescence, and proliferation were analyzed by phase-contrast microscopy, MTT assay, β-galactosidase test, and the trypan blue exclusion assay, respectively. Also, chromosomal stability was evaluated by classical cytogenetic analysis. The average length of telomeres and telomerase reverse transcriptase expression were accessed by real-time PCR and real-time RT-PCR, respectively. The MST-312 showed cytotoxic action and promoted telomere erosion, senescence, and chromosome aberrations, as expected, but in a small proportion. Nevertheless, the proliferation rate of the culture was not affected. As the main effect, the chronic exposure led to cell adaptation by overexpression of telomerase in response to the inhibitor, which is a potential cause of therapeutic failure and may be associated with a poor prognosis. In conclusion, despite the high therapeutic potential of TIs such as MST-312, the molecular outcomes of long-term exposure of tumors on these drugs have to be evaluated when considering their clinical application, especially for breast cancer treatment.

Identifying actionable variants using next generation sequencing in patients with a historical diagnosis of undifferentiated pleomorphic sarcoma

There are limited data regarding the molecular characterization of undifferentiated pleomorphic sarcomas (UPS; formerly malignant fibrous histiocytoma). This study aimed to investigate the utility of next generation sequencing (NGS) in UPS to identify subsets of patients who harbour actionable mutations. Patients diagnosed with UPS underwent pathological re-evaluation by a pathologist specializing in sarcoma. Tumor DNA was isolated from archived fresh frozen tissue samples and genotyped using NGS with the Illumina MiSeq TruSeq Amplicon Cancer Panel (48 genes, 212 amplicons). In total, 95 patients initially classified with UPS were identified. Following pathology re-review the histological subtypes were reclassified to include: Myxofibrosarcoma (MFS, N = 44); UPS(N = 18); and Others (N = 27; including undifferentiated spindle cell sarcoma (N = 15) and dedifferentiated liposarcoma (N = 6)). Seven cases were excluded from further analysis for other reasons. Baseline demographics of the finalized cohort (N = 88) showed a median age of 66 years (32-95), primarily with stage I-III disease (92%) and high-grade (86%) lesions. Somatic mutations were identified in 31 cases (35%)(Total mutations = 36: solitary mutation(n = 27); two mutations( =n = 3); three mutations(n = 1)). The most commonly identified mutations were in TP53 (n = 24), ATM (n = 3) and PIK3CA (n = 2). Three of 43 patients with MFS and one of 18 patients with UPS had clinically relevant mutations, mainly related to biomarkers of prediction of response; however few had targetable driver mutations. Somatic mutation status did not influence disease free or overall survival. Based on the small number of clinically relevant mutations, these data do not support the routine use of targeted NGS panels outside of research protocols in UPS.

Precision medicine for advanced prostate cancer

PURPOSE OF REVIEW

Precision cancer medicine, the use of genomic profiling of patient tumors at the point-of-care to inform treatment decisions, is rapidly changing treatment strategies across cancer types. Precision medicine for advanced prostate cancer may identify new treatment strategies and change clinical practice. In this review, we discuss the potential and challenges of precision medicine in advanced prostate cancer.

RECENT FINDINGS

Although primary prostate cancers do not harbor highly recurrent targetable genomic alterations, recent reports on the genomics of metastatic castration-resistant prostate cancer has shown multiple targetable alterations in castration-resistant prostate cancer metastatic biopsies. Therapeutic implications include targeting prevalent DNA repair pathway alterations with PARP-1 inhibition in genomically defined subsets of patients, among other genomically stratified targets. In addition, multiple recent efforts have demonstrated the promise of liquid tumor profiling (e.g., profiling circulating tumor cells or cell-free tumor DNA) and highlighted the necessary steps to scale these approaches in prostate cancer.

SUMMARY

Although still in the initial phase of precision medicine for prostate cancer, there is extraordinary potential for clinical impact. Efforts to overcome current scientific and clinical barriers will enable widespread use of precision medicine approaches for advanced prostate cancer patients.

Targeting tumor suppressor genes for cancer therapy

Cancer drugs are broadly classified into two categories: cytotoxic chemotherapies and targeted therapies that specifically modulate the activity of one or more proteins involved in cancer. Major advances have been achieved in targeted cancer therapies in the past few decades, which is ascribed to the increasing understanding of molecular mechanisms for cancer initiation and progression. Consequently, monoclonal antibodies and small molecules have been developed to interfere with a specific molecular oncogenic target. Targeting gain-of-function mutations, in general, has been productive. However, it has been a major challenge to use standard pharmacologic approaches to target loss-of-function mutations of tumor suppressor genes. Novel approaches, including synthetic lethality and collateral vulnerability screens, are now being developed to target gene defects in p53, PTEN, and BRCA1/2. Here, we review and summarize the recent findings in cancer genomics, drug development, and molecular cancer biology, which show promise in targeting tumor suppressors in cancer therapeutics.

The Challenges of Precision Oncology Drug Development and Implementation

The drivers of precision medicine are clear: for patients (and physicians)--more options, durable clinical benefit, reduced exposure to non-effective drugs and potential to leverage current scientific and technological advances; for the pharmaceutical industry--the potential to tackle core challenges in discovering and developing better and more efficacious medicines, to reduce rates of attrition in drug development and to reduce development costs; for healthcare systems and payers--improved efficiency through the provision of effective care and avoiding ineffective treatments. Oncology has been at the vanguard, the improvements gained in patient survival notable. However, the increasing number of molecular subgroups requires an equally increasing number (and new generation) of highly selective agents targeting inevitably lower incidence molecular segments. Innovative trial designs (umbrella/basket studies) are emerging as a patient-centric approach to drug development, and the rise in public-private partnerships, cross-industry, government and non-profit sector collaborations is enabling implementation of complex clinical trial designs. This poses significant challenges for healthcare systems and regulatory approval. Further substantial evolution of policy and processes, particularly regulatory requirements for approval for new therapeutics, are required.

Patient-centric trials for therapeutic development in precision oncology

An enhanced understanding of the molecular pathology of disease gained from genomic studies is facilitating the development of treatments that target discrete molecular subclasses of tumours. Considerable associated challenges include how to advance and implement targeted drug-development strategies. Precision medicine centres on delivering the most appropriate therapy to a patient on the basis of clinical and molecular features of their disease. The development of therapeutic agents that target molecular mechanisms is driving innovation in clinical-trial strategies. Although progress has been made, modifications to existing core paradigms in oncology drug development will be required to realize fully the promise of precision medicine.