Larotrectinib efficacy and safety in adult patients with tropomyosin receptor kinase fusion sarcomas

Background

Larotrectinib, a first-in-class, highly selective tropomyosin receptor kinase (TRK) inhibitor, has demonstrated efficacy in adult and pediatric patients with various solid tumors harboring NTRK gene fusions. This subset analysis focuses on the efficacy and safety of larotrectinib in an expanded cohort of adult patients with TRK fusion sarcomas.

Methods

Patients (≥18 years old) with sarcomas harboring NTRK gene fusions were identified from three clinical trials. Patients received larotrectinib 100 mg orally twice daily. Response was investigator-assessed per RECIST v1.1. Data cutoff was July 20, 2021.

Results

At the data cutoff, 36 adult patients with TRK fusion sarcomas had initiated larotrectinib therapy: two (6%) patients had bone sarcomas, four (11%) had gastrointestinal stromal tumors, and 30 (83%) had soft tissue sarcomas. All patients were evaluable for response and demonstrated an objective response rate of 58% (95% confidence interval, 41–74). Patients responded well to larotrectinib regardless of number of prior lines of therapy. Adverse events (AEs) were mostly grade 1/2. Grade 3 treatment-emergent AEs (TEAEs) occurred in 15 (42%) patients. There were no grade 4 TEAEs. Two grade 5 TEAEs were reported, neither of which were considered related to larotrectinib. Four (11%) patients permanently discontinued treatment due to TEAEs.

Conclusions

Larotrectinib demonstrated robust and durable responses, extended survival benefit, and a favorable safety profile in adult patients with TRK fusion sarcomas with longer follow-up. These results continue to demonstrate that testing for NTRK gene fusions should be incorporated into the clinical management of adult patients with various types of sarcomas.

Plain Language Summary

• Tropomyosin receptor kinase (TRK) fusion proteins result from translocations involving the NTRK gene and cause cancer in a range of tumor types.
• Larotrectinib is an agent that specifically targets TRK fusion proteins and is approved for the treatment of patients with TRK fusion cancer.
• This study looked at how well larotrectinib worked in adult patients with sarcomas caused by TRK fusion proteins.
• Over half of patients had a durable response to larotrectinib, with no unexpected side effects.
• These results show that larotrectinib is safe and effective in adult patients with TRK fusion sarcomas.

     

Efficacy and safety of larotrectinib in TRK fusion-positive primary central nervous system tumors

BackgroundLarotrectinib is a first-in-class, highly selective tropomyosin receptor kinase (TRK) inhibitor approved to treat adult and pediatric patients with TRK fusion-positive cancer. The aim of this study was to evaluate the efficacy and safety of larotrectinib in patients with TRK fusion-positive primary central nervous system (CNS) tumors.MethodsPatients with TRK fusion-positive primary CNS tumors from two clinical trials ({"type":"clinical-trial","attrs":{"text":"NCT02637687","term_id":"NCT02637687"}}NCT02637687, {"type":"clinical-trial","attrs":{"text":"NCT02576431","term_id":"NCT02576431"}}NCT02576431) were identified. The primary endpoint was investigator-assessed objective response rate (ORR).ResultsAs of July 2020, 33 patients with TRK fusion-positive CNS tumors were identified (median age: 8.9 years; range: 1.3–79.0). The most common histologies were high-grade glioma (HGG; n = 19) and low-grade glioma (LGG; n = 8). ORR was 30% (95% confidence interval [CI]: 16–49) for all patients. The 24-week disease control rate was 73% (95% CI: 54–87). Twenty-three of 28 patients (82%) with measurable disease had tumor shrinkage. The 12-month rates for duration of response, progression-free survival, and overall survival were 75% (95% CI: 45–100), 56% (95% CI: 38–74), and 85% (95% CI: 71–99), respectively. Median time to response was 1.9 months (range 1.0–3.8 months). Duration of treatment ranged from 1.2–31.3+ months. Treatment-related adverse events were reported for 20 patients, with grade 3–4 in 3 patients. No new safety signals were identified.ConclusionsIn patients with TRK fusion-positive CNS tumors, larotrectinib demonstrated rapid and durable responses, high disease control rate, and a favorable safety profile.     

Canadian Consensus for Biomarker Testing and Treatment of TRK Fusion Cancer in Adults

The tyrosine receptor kinase (TRK) inhibitors larotrectinib and entrectinib were recently approved in Canada for the treatment of solid tumours harbouring neurotrophic tyrosine receptor kinase (NTRK) gene fusions. These NTRK gene fusions are oncogenic drivers found in most tumour types at a low frequency (<5%), and at a higher frequency (>80%) in a small number of rare tumours (e.g., secretory carcinoma of the salivary gland and of the breast). They are generally mutually exclusive of other common oncogenic drivers. Larotrectinib and entrectinib have demonstrated impressive overall response rates and tolerability in Phase I/II trials in patients with TRK fusion cancer with no other effective treatment options. Given the low frequency of TRK fusion cancer and the heterogeneous molecular testing landscape in Canada, identifying and optimally managing such patients represents a new challenge. We provide a Canadian consensus on when and how to test for NTRK gene fusions and when to consider treatment with a TRK inhibitor. We focus on five tumour types: thyroid carcinoma, colorectal carcinoma, non-small cell lung carcinoma, soft tissue sarcoma, and salivary gland carcinoma. Based on the probability of the tumour harbouring an NTRK gene fusion, we also suggest a tumour-agnostic consensus for NTRK gene fusion testing and treatment. We recommend considering a TRK inhibitor in all patients with TRK fusion cancer with no other effective treatment options.     

Canadian Consensus for Biomarker Testing and Treatment of TRK Fusion Cancer in Pediatric Patients

Neurotrophic tyrosine receptor kinase gene fusions (NTRK) are oncogenic drivers present at a low frequency in most tumour types (<5%), and at a higher frequency (>80%) in a small number of rare tumours (e.g., infantile fibrosarcoma [IFS]) and considered mutually exclusive with other common oncogenic drivers. Health Canada recently approved two tyrosine receptor kinase (TRK) inhibitors, larotrectinib (for adults and children) and entrectinib (for adults), for the treatment of solid tumours harbouring NTRK gene fusions. In Phase I/II trials, these TRK inhibitors have demonstrated promising overall response rates and tolerability in patients with TRK fusion cancer who have exhausted other treatment options. In these studies, children appear to have similar responses and tolerability to adults. In this report, we provide a Canadian consensus on when and how to test for NTRK gene fusions and when to consider treatment with a TRK inhibitor for pediatric patients with solid tumours. We focus on three pediatric tumour types: non-rhabdomyosarcoma soft tissue sarcoma/unspecified spindle cell tumours including IFS, differentiated thyroid carcinoma, and glioma. We also propose a tumour-agnostic consensus based on the probability of the tumour harbouring an NTRK gene fusion. For children with locally advanced or metastatic TRK fusion cancer who have either failed upfront therapy or lack satisfactory treatment options, TRK inhibitor therapy should be considered.     

China special issue on gastrointestinal tumors—NTRK fusion in a large real-world population and clinical utility of circulating tumor DNA genotyping to guide TRK inhibitor treatment

Neurotrophic tropomyosin receptor kinase (NTRK) gene fusions are rare oncogenic drivers and targets of TRK inhibitors in solid tumors. Little is known about NTRK fusion in Chinese patients with pan-cancer. Our study investigated the prevalence and genomic features of NTRK1/2/3 gene fusions in 67 883 Chinese patients with pan-cancer using next-generation sequencing (NGS) data and circulating tumor DNA (ctDNA) NGS to guide TRK inhibitor treatment and resistance monitoring. The prevalence of NTRK fusion (tissue NGS) in the pan-cancer population was 0.18%, with 46 unique NTRK-fusion partner pairs, of which 33 were not previously reported. NTRK2 breakpoint occurred more frequently in intron 15 than intron 12. In colorectal cancers (CRCs), compared to NTRK-negative tumors, NTRK-positive tumors displayed higher tumor mutational burden (TMB) levels (54.6 vs 17.7 mut/Mb, P < .0001). In microsatellite instability-high (MSI-H) CRC, patients with NTRK fusion had a significantly lower TMB than NTRK-negative cases (69.3 vs 79.9 mut/Mb, P = .012). The frequency of NTRK fusion in a ctDNA NGS cohort of 20 954 patients with cancer was similar to that of the tissue NGS cohort. In eight NTRK fusion ctDNA-positive patients, larotrectinib induced objective response in 75% of patients and median progression-free survival was 16.3 months. Blood samples collected from a patient with disease progression after larotrectinib treatment revealed NTRK3 G623R as the potential resistance mechanism. Our study revealed previously unreported NTRK fusion partners, associations of NTRK fusion with MSI and TMB, and the potential utility of ctDNA to screen candidates for TRK inhibitors and monitor drug resistance.     

CAR-T细胞治疗实体肿瘤的新策略

[摘要] 嵌合型抗原受体修饰T(chimeric antigen receptor modified T,CAR-T)细胞治疗作为一种新的过继性免疫疗法在血液肿瘤中已取得了较好的疗效。在实体肿瘤中,肿瘤微环境中存在大量免疫抑制细胞、免疫抑制分子以及胞外基质,对迁移的CAR-T细胞的细胞毒性效应产生抑制作用,在实体肿瘤内严重抑制CAR-T细胞的抗肿瘤效力。同时,大多数实体肿瘤存在肿瘤异质性且缺乏相对特异性肿瘤抗原,CAR-T细胞在实体肿瘤部位的归巢能力差并伴随着脱靶效应,使其在实体瘤中的疗效欠佳。与血液肿瘤相比,实体瘤具有复杂的生物学特性,需要针对性的策略才能保证CAR-T细胞抗肿瘤长期有效。本文就CAR-T 细胞的发展、在实体瘤治疗中的困惑及治疗策略的研究进展作一阐述。     

Fusion genes in solid tumors： an emerging target for cancer diaanosis and treatment

Studies over the past decades have uncovered fusion genes, a class of oncogenes that provide immense diagnostic and therapeutic advantages because of their tumor-specific expression. Originally associated with hemotologic cancers, fusion genes have recently been discovered in a wide array of solid tumors, including sarcomas, carcinomas, and tumors of the central nervous system. Fusion genes are attractive as both therapeutic targets and diagnostic tools due to their inherent expression in tumor tissue alone. Therefore, the discovery and elucidation of fusion genes in various cancer types may provide more effective therapies in the future for cancer patients.     

Fusion genes in solid tumors: an emerging target for cancer diagnosis and treatment

Studies over the past decades have uncovered fusion genes, a class of oncogenes that provide immense diagnostic and therapeutic advantages because of their tumor-specific expression. Originally associated with hemotologic cancers, fusion genes have recently been discovered in a wide array of solid tumors, including sarcomas, carcinomas, and tumors of the central nervous system. Fusion genes are attractive as both therapeutic targets and diagnostic tools due to their inherent expression in tumor tissue alone. Therefore, the discovery and elucidation of fusion genes in various cancer types may provide more effective therapies in the future for cancer patients.     

Phase I study of pazopanib in combination with weekly paclitaxel in patients with advanced solid tumors

Purpose.

To evaluate the maximum tolerated regimen (MTR), dose-limiting toxicities, and pharmacokinetics of pazopanib, an oral small-molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit, in combination with paclitaxel.

Patients and Methods.

Pazopanib was given daily with weekly paclitaxel on days 1, 8, and 15 every 28 days. Dose levels of pazopanib (mg/day)/paclitaxel (mg/m²) were 400/15, 800/15, 800/50, and 800/80. An expanded cohort was enrolled at the MTR. Plasma samples were collected to evaluate the effect of pazopanib, an inhibitor of cytochrome P450 (CYP)3A4, on the pharmacokinetics of paclitaxel, a CYP3A4 and CYP2C8 substrate.

Results.

Of 26 enrolled patients, 17 were treated at the MTR of 800 mg pazopanib and 80 mg/m² paclitaxel. Dose-limiting toxicities included a grade 3 abscess and grade 2 hyperbilirubinemia. Other toxicities included elevated liver transaminases and diarrhea. Six patients (23%) had partial responses and 15 patients (58%) had stable disease. Administration of 800 mg pazopanib resulted in a 14% lower paclitaxel clearance and a 31% higher paclitaxel maximal concentration than with administration of paclitaxel alone at 15, 50, and 80 mg/m². At the MTR, coadministration of 800 mg pazopanib and 80 mg/m² paclitaxel resulted in a 26% higher geometric mean paclitaxel area under the curve.

Conclusion.

Pazopanib, at a dose of 800 mg daily, can be safely combined with a therapeutic dose of paclitaxel at 80 mg/m² when administered on days 1, 8, and 15, every 28 days. The observed greater plasma concentrations of paclitaxel given concurrently with pazopanib suggest that pazopanib is a weak inhibitor of CYP3A4 and CYP2C8.     

Topoisomerase I inhibitors for the treatment of brain tumors

Patients with primary malignant brain tumors have a poor prognosis. Standard treatment includes surgical resection, radiation therapy and chemotherapy. Topoisomerase I inhibitors such as topotecan and irinotecan (CPT-11) represent one class of chemotherapy drugs that have been used in this disease. Recent clinical trials have shown major antitumor activity in recurrent glioblastoma when adding the antiangiogenesis drug bevacizumab with CPT-11. The combination of targeted agents to topoisomerase I inhibitors represent a novel and promising approach. This review will summarize clinical trials with topoisomerase I inhibitors and discuss new treatment strategies for primary malignant brain tumors.     

巨噬细胞相关的实体瘤治疗新策略

巨噬细胞在实体瘤的发生发展中起着重要作用,基于巨噬细胞的实体瘤治疗也取得了阶段性的成果。与巨噬细胞相关的实体瘤治疗新策略主要包括：调节肿瘤相关巨噬细胞的数量和表型及构建嵌合抗原受体巨噬细胞（CAR-M）,前者通过抑制巨噬细胞募集、耗竭肿瘤相关巨噬细胞（TAM）和重编程TAM等方式,减弱TAM对实体瘤的促进作用,增强TAM的抗肿瘤效应;后者基于CAR-T 的设计原理,使得巨噬细胞能够特异性识别肿瘤细胞表面抗原,并利用巨噬细胞较强的浸润能力,使得CAR-M能够进入实体瘤发挥抗肿瘤效应。目前,CAR-M疗法已在动物模型中获得了成功,相关临床研究正在进行,尚未获得明确的结论。TAM具有良好的组织浸润能力、吞噬活性和安全性,在实体瘤治疗中展现出广阔的前景,进一步研究TAM表型极化的机制、解决巨噬细胞来源问题、优化CAR-M的体外转染策略,将有效推动巨噬细胞在实体瘤治疗中的应用。     

Evidence for Taxotere treatment with solid tumors

Evidence based medicine is essential to further develop the state of the art for cancer treatments. We introduce the levels of evidence for Taxotere treatment against various solid tumors. Most evidence for Taxotere therapy was produced in other countries. However, in Japan we have some data from phase II clinical trials for the approval of Taxotere. We review these domestic results, which reveal its usefulness and toxicity in Japanese patients. In addition, we analyze the evidence from the data of clinical trials of Taxotere conducted by investigators in the USA/Europe. Japanese physicians or academies must build a consensus for the application of Taxotere to Japanese patients with solid tumors.     

尼妥珠单抗治疗实体瘤的研究进展

尼妥珠单抗（泰欣生）是一种靶向表皮生长因子受体（EGFR）的人源化单克隆抗体,可特异性与EGFR胞外域结合,阻断下游信号通路而起到抗肿瘤作用。临床研究表明,尼妥珠单抗在头颈部鳞状细胞癌、鼻咽癌和胶质瘤等实体瘤中显示出良好的抗肿瘤作用,同时具有耐受性好、皮疹发生率低等优点。     

A proapoptotic peptide for the treatment of solid tumors.

We have designed a novel peptide, DP1, which is able to mediate significant induction of apoptosis in solid tumors by local injection. This peptide, comprised of a protein transduction domain (PTD), PTD-5, fused to an antimicrobial peptide, (KLAKLAK)2, was able to trigger rapid apoptosis in a variety of cell lines in vitro, including MCA205 murine fibrosarcomas and human head and neck tumors. Furthermore, direct injection of DP1 into day 7 established MCA205 tumors in C57BL/6 mice resulted in the induction of tumor apoptosis and subsequent reduction in tumor volume. These results suggest that DP1 may be used clinically to treat accessible solid tumors or as an adjuvant therapy in conjunction with radiotherapy, standard chemotherapy, immunotherapy, or surgical debulking.     

实体肿瘤免疫治疗的关键问题与对策

近年来,肿瘤免疫治疗取得重大突破性进展,以CAR-T为代表的细胞免疫治疗在血液肿瘤的治疗中取得了令人鼓舞的临床疗效,免疫卡控点抑制剂CTLA4和PD-1/PD-L1单抗也相继获批用于临床.然而,大多数实体肿瘤患者并不能从免疫治疗中获益.本文从个体化新抗原表位的筛选、免疫细胞活力的维持、免疫细胞趋化与浸润、临床治疗模式和评价标准等方面总结了实体肿瘤免疫治疗难以见效的关键问题,并且从临床应用角度阐述其应对策略.     

嵌合抗原受体T细胞治疗实体瘤的研究进展和挑战

随着嵌合抗原受体疗法在血液系统癌症中的惊人疗效,研究者们也在实体瘤方面展开探索。我们将回顾近年来嵌合抗原受体T细胞（CAR-T）治疗卵巢癌、肺癌、肝癌等实体瘤的研究进展;还将对CAR-T细胞治疗实体瘤的局限性,即抗原特异性问题、CAR-T细胞贩运问题以及肿瘤微环境问题结合相应对策进行综述。