Nature Reviews. Drug Discovery | Development and Challenges of Tumour-Agnostic Kinase Inhibitors

This article systematically reviews the development of tumour-agnostic kinase inhibitors targeting molecular pathways rather than tissue origin, covering clinical evidence and resistance mechanisms for targets such as NTRK, RET, and BRAF, revealing a new paradigm in precision medicine.

 

Literature Overview

The article 'Tumour-agnostic kinase inhibitors,' published in Nature Reviews. Drug Discovery, reviews and summarizes the development, clinical efficacy, resistance mechanisms, and challenges of biomarker-driven small-molecule kinase inhibitors. The paper highlights the therapeutic applications of kinase targets such as NTRK, RET, BRAF/MEK, and FGFR across various solid and hematologic malignancies, emphasizing the central role of next-generation sequencing (NGS) in patient selection. It also discusses how innovative trial designs, such as basket trials, accelerate drug approval. Although several drugs have received tissue-agnostic approval, most remain limited to solid tumors and face challenges including the difficulty of identifying rare targets and frequent resistance mutations. The article analyzes the pan-cancer potential of emerging targets like ALK, KRASG12C, and HER2, suggesting that future development must balance biological understanding with clinical feasibility. The entire section is coherent and logically structured, ending with a period in Chinese.

Background Knowledge

Tumour-agnostic therapy, also known as 'tissue-agnostic' treatment, refers to therapeutic strategies based on molecular features rather than the tumor's tissue of origin. The rationale is that certain driver genetic alterations (e.g., kinase fusions or mutations) can independently drive oncogenesis across different tumor types, forming 'molecularly defined cancers.' Protein kinases, as critical nodes in signal transduction, are frequently abnormally activated in cancer and thus serve as important drug targets. With the widespread adoption of high-throughput genomic sequencing, an increasing number of kinase targets have been identified as pan-cancer drivers. For example, although NTRK gene fusions are rare overall (~0.3%), they occur at high frequency in rare tumors such as infantile fibrosarcoma and exhibit high sensitivity to TRK inhibitors. Similarly, gene rearrangements in RET, ALK, and FGFR occur across multiple cancer types, offering opportunities for targeted therapy. However, developing such therapies faces significant challenges: first, target alterations are extremely rare in common cancers, requiring large-scale screening for patient enrollment; second, resistance mechanisms are complex, such as kinase domain mutations that reduce drug binding; third, efficacy of certain targets varies significantly across tissues (e.g., poor response to BRAF inhibitors in colorectal cancer), suggesting the need for combination strategies. Therefore, efficiently identifying patients with targetable alterations, overcoming resistance, and extending these therapies to hematologic malignancies have become key research areas. This study systematically reviews approved and investigational kinase inhibitors, providing valuable guidance for future drug development.

 

 

Research Methods and Experiments

The article employs a systematic literature review approach, integrating data from key clinical trials, including phase I/II single-arm basket trials (e.g., NAVIGATE, STARTRK, FIGHT-202) and multicenter real-world studies. It focuses on FDA-approved tumour-agnostic kinase inhibitors such as larotrectinib, entrectinib, and repotrectinib (targeting NTRK fusions), selpercatinib (targeting RET fusions), dabrafenib/trametinib (targeting BRAFV600E mutations), and pemigatinib (targeting FGFR1 rearrangements). Efficacy was assessed using objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). The study also includes pan-cancer clinical data for KRASG12C inhibitors (e.g., sotorasib, adagrasib) and HER2-targeted agents to evaluate their cross-tumor activity. Additionally, the authors analyze resistance mechanisms, particularly acquired kinase domain mutations (e.g., solvent-front and gatekeeper mutations in NTRK), and their impact on treatment. The paper also discusses the value of novel trial designs such as basket and umbrella trials in accelerating drug development.

Key Conclusions and Perspectives

• Several small-molecule kinase inhibitors have received FDA tumour-agnostic approval, including larotrectinib, entrectinib, and repotrectinib (NTRK fusions), selpercatinib (RET fusions), and dabrafenib/trametinib (BRAFV600E mutations), indicating that molecularly targeted therapies are increasingly moving beyond histological constraints
• Despite progress, nearly all tumour-agnostic approvals do not cover both solid and hematologic tumors, showing limitations in indications. For example, pemigatinib is approved for FGFR1-rearranged hematologic malignancies, but most other drugs are limited to solid tumors
• Basket trials are a key design for advancing tumour-agnostic drug development, enabling validation of pan-cancer efficacy by enrolling patients with specific genetic alterations regardless of tumor type
• Targets such as NTRK, RET, and BRAF are frequently found in rare tumors but have low overall mutation rates in common cancers (e.g., NTRK fusions ~0.3%), making patient selection difficult and necessitating large-scale NGS testing
• Resistance remains a major challenge; common mechanisms for NTRK inhibitors include acquired kinase domain mutations (e.g., G667C, G696C). Second-generation inhibitors like repotrectinib can overcome some resistance mutations, but difficult-to-treat cases such as double mutations persist
• Emerging targets such as KRASG12C and HER2 mutations/amplifications show pan-cancer activity. KRASG12C inhibitors sotorasib and adagrasib demonstrate antitumor activity in NSCLC, colorectal cancer, and cholangiocarcinoma, supporting their potential as tumour-agnostic targets
• The HER2-targeted antibody-drug conjugate trastuzumab deruxtecan has received tumour-agnostic approval based on IHC protein expression, becoming the first tissue-agnostic therapy not reliant on genetic alterations, thus expanding the definition of biomarkers
• The success of precision medicine depends on the widespread adoption of molecular diagnostics like NGS. Future efforts must improve testing accessibility to ensure patients with targetable alterations are promptly identified and treated

Research Significance and Prospects

This study provides a comprehensive summary of the clinical progress and challenges in tumour-agnostic kinase inhibitors, highlighting the shift from 'histology-driven' to 'molecularly driven' treatment paradigms. Its significance lies in offering drug developers a clear target-drug matching framework and demonstrating the feasibility of basket trials in developing drugs for rare alterations. The article also points out current limitations, such as incomplete tumor type coverage and complex resistance mechanisms, suggesting the need for next-generation inhibitors with broader and more durable efficacy.

Looking ahead, as multi-omics data accumulate and AI-assisted target discovery advances, more pan-cancer driver kinases will be identified. Overcoming resistance will require developing reversible or covalent inhibitors, bispecific molecules, or combination therapies. Additionally, extending these strategies to hematologic malignancies requires further research. Ultimately, achieving truly 'pan-cancer' precision therapy will require addressing systemic issues such as testing costs, healthcare accessibility, and heterogeneous treatment responses.

 

 

Conclusion

This article provides a comprehensive review of the current state of tumour-agnostic kinase inhibitor development, highlighting the immense potential of precision medicine strategies based on molecular characteristics rather than tissue origin. Several drugs targeting kinases such as NTRK, RET, and BRAF have received FDA approval, significantly improving outcomes for patients with advanced cancers harboring these alterations. However, these therapies are largely limited to solid tumors and face challenges due to the rarity of targets and frequent resistance. Basket trials and NGS-based testing are core tools driving the development of these agents. The pan-cancer activity of emerging targets like KRASG12C and HER2 further expands the therapeutic landscape. Future research should focus on overcoming resistance, enhancing drug breadth, and increasing testing accessibility to achieve truly personalized pan-cancer therapy. This review serves as a valuable resource for clinicians and drug developers, marking a new era in precision oncology.

 

Jacob J Adashek, Mina Nikanjam, and Razelle Kurzrock. Tumour-agnostic kinase inhibitors. Nature reviews. Drug discovery.