Site-agnostic biomarker-guided oncology drug development

The Potential of Trastuzumab Deruxtecan as a Tissue Agnostic Drug

BACKGROUND

Many modern anticancer drugs are designed to target specific molecular alterations harbored by the cancer. If a specific drug is able to target these alterations, regardless of the organ or tissue in which the cancer originates, it will often be characterized as a tissue- or tumor agnostic drug. According to the Food and Drug Administration (FDA), a tissue-agnostic drug refers to a drug that targets a specific molecular alteration across multiple cancer types, as defined by organ, tissue, or tumor type.

SUMMARY

Over the last 6 years, the FDA has approved seven tissue-agnostic drugs, and more are anticipated in the future. One promising candidate for a tissue-agnostic classification is the antibody-drug conjugate trastuzumab deruxtecan (T-DXd). Currently, T-DXd is approved for the treatment of human epidermal growth factor receptor 2 (HER2)-positive and HER2-low breast cancer, HER2-positive gastric or gastroesophageal junction adenocarcinoma, and non-small cell lung cancer with activating HER2 mutations. Ongoing clinical research is exploring the potential of T-DXd in various solid tumors that harbor specific HER2 molecular alterations, and encouraging results, including the interim data from the DESTINY-PanTumor02 trial, have been published, which suggest a tissue-agnostic potential.

KEY MESSAGES

Published phase I data as well as the interim results from the phase II DESTINY-PanTumor02 trial indicates that patients with different HER2-positive advanced solid tumors may benefit from treatment with T-DXd. Based on the currently available data, it seems likely that T-DXd possesses pantumor activity. However, different clinical trials are ongoing, and it will be necessary to see the results from these trials before drawing a final conclusion. When discussing tissue-agnostic potential, it is important to add that for most of the patients enrolled in the DESTINY-PanTumor02 and other trials, few treatment alternatives seem to exist, and T-DXd might be able to cover an unmet medical need.

The significance of tissue-agnostic biomarkers in solid tumors: the more the merrier?

INTRODUCTION

To date, several emerging biomarkers have gained considerable interest in the field of predictive molecular oncology. The advent of precision medicine has led to the development of innovative drugs targeting rare molecular pathways independently from histology, defined as tissue-agnostic drugs.

AREAS COVERED

Although there is a lot of promise for this new tissue-agnostic model in the oncological scenario, crucial issues from both the diagnostic and therapeutic standpoint are emerging. This review aims to critically examine the role of tissue-agnostic biomarkers in different solid tumors, focusing on the prevalence and methods of detection of agnostic biomarkers together with drug approvals to guide clinicians in this evolving landscape.

EXPERT OPINION

To strengthen the framework for tissue-agnostic approvals, the dialogue between regulatory, industrial, and academic parties should be intensified. Critical questions include the development of an efficient network system that can overcome the heterogeneity of patients' inclusion criteria along with the increasingly difficult interpretation of next-generation sequencing (NGS) profiling technologies. Cost-effectiveness and risk-benefit studies are needed in the national context considering the modalities of access to diagnostic tests and reimbursement of treatments.

Challenges and Solutions for the Benefit Assessment of Tumor-Agnostic Therapies in Germany

OBJECTIVES

Precision medicine is increasingly important in cancer treatment. Tumor-agnostic therapies are used regardless of tumor entity because they target specific biomarkers in tumors. In Germany, the benefit assessment of oncological pharmaceuticals has traditionally been entity specific. Thus, the assessment of tumor-agnostic therapies leaves stakeholders with various challenges. Our aim was to systematically identify challenges and possible solutions for the benefit assessment of therapies in tumor-agnostic indications using a 2-step sequential qualitative approach.

METHODS

To identify relevant challenges, we conducted qualitative interviews with different stakeholders who were involved in previous benefit assessments of tumor-agnostic therapies in Germany. To identify possible solutions for these challenges, we systematically searched MEDLINE, Embase, and the websites of European health technology assessment bodies for relevant literature.

RESULTS

We identified 9 categories of challenges of which the following were deemed particularly relevant: the absence of direct comparative studies, challenges regarding the use of basket studies and indirect comparisons, challenges in determining the appropriate comparative therapy in a tumor-agnostic indication, and challenges on the system side. Seven categories of solutions were identified, including an increased use of real-world evidence, making conditional decisions in the context of systematic reassessments, splitting the field of application, and finding (new) ways to design and analyze basket studies.

CONCLUSION

A range of possible solutions, which can help to meet the identified challenges in Germany, have been found. Future research should investigate the acceptance and feasibility of these solutions.

Extrapolating evidence for molecularly targeted therapies from common to rare cancers: a scoping review of methodological guidance

OBJECTIVES

Cancer is increasingly classified according to biomarkers that drive tumour growth and therapies developed to target them. In rare biomarker-defined cancers, randomised controlled trials to adequately assess targeted therapies may be infeasible. Extrapolating existing evidence of targeted therapy from common cancers to rare cancers sharing the same biomarker may reduce evidence requirements for regulatory approval in rare cancers. It is unclear whether guidelines exist for extrapolation. We sought to identify methodological guidance for extrapolating evidence from targeted therapies used for common cancers to rare biomarker-defined cancers.

DESIGN

Scoping review.

DATA SOURCES

Websites of health technology assessment agencies, regulatory bodies, research groups, scientific societies and industry. EBM Reviews-Cochrane Methodology Register and Health Technology Assessment, Embase and MEDLINE databases (1946 to 11 May 2022).

ELIGIBILITY CRITERIA

Papers proposing a framework or recommendations for extrapolating evidence for rare cancers, small populations and biomarker-defined cancers.

DATA EXTRACTION AND SYNTHESIS

We extracted framework details where available and guidance for components of extrapolation. We used these components to structure and summarise recommendations.

RESULTS

We identified 23 papers. One paper provided an extrapolation framework but was not cancer specific. Extrapolation recommendations addressed six distinct components: strategies for grouping cancers as the same biomarker-defined disease; analytical validation requirements of a biomarker test to use across cancer types; strategies to generate control data when a randomised concurrent control arm is infeasible; sources to inform biomarker clinical utility assessment in the absence of prospective clinical evidence; requirements for surrogate endpoints chosen for the rare cancer; and assessing and augmenting safety data in the rare cancer.

CONCLUSIONS

In the absence of an established framework, our recommendations for components of extrapolation can be used to guide discussions about interpreting evidence to support extrapolation. The review can inform the development of an extrapolation framework for biomarker-targeted therapies in rare cancers.

Characterization of KRC-108 as a TrkA Kinase Inhibitor with Anti-Tumor Effects

Tropomyosin receptor kinase A (TrkA) protein is a receptor tyrosine kinase encoded by the NTRK1 gene. TrkA signaling mediates the proliferation, differentiation, and survival of neurons and other cells following stimulation by its ligand, the nerve growth factor. Chromosomal rearrangements of the NTRK1 gene result in the generation of TrkA fusion protein, which is known to cause deregulation of TrkA signaling. Targeting TrkA activity represents a promising strategy for the treatment of cancers that harbor the TrkA fusion protein. In this study, we evaluated the TrkA-inhibitory activity of the benzoxazole compound KRC-108. KRC-108 inhibited TrkA activity in an in vitro kinase assay, and suppressed the growth of KM12C colon cancer cells harboring an NTRK1 gene fusion. KRC-108 treatment induced cell cycle arrest, apoptotic cell death, and autophagy. KRC-108 suppressed the phosphorylation of downstream signaling molecules of TrkA, including Akt, phospholipase Cγ, and ERK1/2. Furthermore, KRC-108 exhibited anti-tumor activity in vivo in a KM12C cell xenograft model. These results indicate that KRC-108 may be a promising therapeutic agent for Trk fusion-positive cancers.

Current status of precision medicine in pediatric oncology in Spain: a consensus report by the Spanish Society of Paediatric Haematology and Oncology (SEHOP)

The study analyzes the current status of personalized medicine in pediatric oncology in Spain. It gathers national data on the tumor molecular studies and genomic sequencing carried out at diagnosis and at relapse, the centers that perform these studies, the technology used and the interpretation and clinical applicability of the results. Current challenges and future directions to achieve a coordinated national personalized medicine strategy in pediatric oncology are also discussed. Next generation sequencing-based (NGS) gene panels are the technology used in the majority of centers and financial limitations are the main reason for not incorporating these studies into routine care. Nowadays, the application of precision medicine in pediatric oncology is a reality in a great number of Spanish centers. However, its implementation is uneven and lacks standardization of protocols; therefore, national coordination to overcome the inequalities is required. Collaborative work within the Personalized Medicine Group of SEHOP is an adequate framework for encouraging a step forward in the effort to move precision medicine into the national healthcare system.

TRK Inhibitors: Tissue-Agnostic Anti-Cancer Drugs

Recently, two tropomycin receptor kinase (Trk) inhibitors, larotrectinib and entrectinib, have been approved for Trk fusion-positive cancer patients. Clinical trials for larotrectinib and entrectinib were performed with patients selected based on the presence of Trk fusion, regardless of cancer type. This unique approach, called tissue-agnostic development, expedited the process of Trk inhibitor development. In the present review, the development processes of larotrectinib and entrectinib have been described, along with discussion on other Trk inhibitors currently in clinical trials. The on-target effects of Trk inhibitors in Trk signaling exhibit adverse effects on the central nervous system, such as withdrawal pain, weight gain, and dizziness. A next generation sequencing-based method has been approved for companion diagnostics of larotrectinib, which can detect various types of Trk fusions in tumor samples. With the adoption of the tissue-agnostic approach, the development of Trk inhibitors has been accelerated.

Colon Cancer Biomarkers: Implications for Personalized Medicine

The heterogeneity of colon cancers and their reactions presents both a challenge and promise for personalized medicine. The challenge is to develop effective biologically personalized therapeutics guided by predictive and prognostic biomarkers. Presently, there are several classes of candidate biomarkers, including genomic probes, inhibitory RNAs, assays for immunity dysfunction and, not to be forgotten, specific histopathologic and histochemical features. To develop effective therapeutics, candidate biomarkers must be qualified and validated in comparable independent cohorts, no small undertaking. This process and subsequent deployment in clinical practice involves not only the strong association of the biomarker with the treatment but also careful attention to the prosaic aspects of representative tumor site selection, obtaining a fully adequate sample which is preserved and prepared to optimize high quality analysis. In the future, the clinical utility of biomarker analytical results will benefit from associated clinical and basic science data with the assistance of artificial intelligence techniques. By application of an individualized, selected suite of biomarkers, comprehensively interpreted, individualized, more effective and less toxic therapy for colon cancer will be enabled, thereby fulfilling the promise of personalized medicine.