Durable Clinical Response to ALK Tyrosine Kinase Inhibitors in Epithelioid Inflammatory Myofibroblastic Sarcoma Harboring PRRC2B-ALK Rearrangement: A Case Report

Podcast on Emerging Treatment Options for Pediatric Patients with ALK-Positive Anaplastic Large Cell Lymphoma and Inflammatory Myofibroblastic Tumors

Anaplastic large cell lymphoma (ALCL) and inflammatory myofibroblastic tumor (IMT) are rare cancers observed predominantly in children and young adults. ALCL accounts for 10-15% of all pediatric non-Hodgkin lymphomas and is commonly diagnosed at an advanced stage of disease. In children, 84-91% of cases of ALCL harbor an anaplastic lymphoma kinase (ALK) gene translocation. IMT is a rare mesenchymal neoplasm that also tends to occur in children and adolescents. Approximately 50-70% of IMT cases involve rearrangements in the ALK gene. A combination of chemotherapeutic drugs is typically used for children with ALK-positive ALCL, and the only known curative therapy for ALK-positive IMT is complete surgical resection. Crizotinib, a first-generation ALK inhibitor, was approved in the USA in 2021 for pediatric patients and young adults with relapsed or refractory ALK-positive ALCL; however, its safety and efficacy have not been established in older adults. In 2022, crizotinib was approved for adult and pediatric patients with unresectable, recurrent, or refractory ALK-positive IMT. This podcast provides an overview of ALK-positive ALCL and IMT. We discuss the current treatment landscape, the role of ALK tyrosine kinase inhibitors, and areas of future research.

Abdominal inflammatory myofibroblastic tumour: Clinicopathological and molecular analysis of 20 cases, highlighting potential therapeutic targets

AIMS

Inflammatory myofibroblastic tumour (IMT) is a rare mesenchymal neoplasm of intermediate malignant potential, occurring at any age and at multiple sites. Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive subtype of IMT, typically involving the abdomen. Most IMTs harbour kinase gene fusions, especially involving ALK and ROS1, but 20-30% of IMTs show no detectable translocations. The aim of this study is to further delineate clinicopathological and molecular characteristics of abdominal IMT and discover potential new therapeutic targets.

METHODS AND RESULTS

In 20 IMTs, including four EIMS, RNA fusion analysis was performed, followed by multiplex DNA analysis if no ALK or ROS1 fusion was detected. Fourteen IMTs (70.0%) had an ALK translocation and the fusion partner was identified in 11, including a RRBP1::ALK fusion, not previously described in classical (non-EIMS) IMT. RANBP2::ALK fusion was demonstrated in all EIMS. One IMT had a ROS1 fusion. In all ALK/ROS1 translocation-negative IMTs mutations or fusions - as yet unreported in primary IMT - were found in genes related to the receptor tyrosine kinase (RTK)/PI3K/AKT pathway. Three of four patients with EIMS died of disease [mean survival 8 months (4-15 months)], whereas only one of 14 classical IMT patients succumbed to disease [mean follow-up time 52 months (2-204 months); P < 0.01].

CONCLUSION

This study shows the wide clinical spectrum of abdominal IMTs and affirms the poor prognosis of EIMS, raising discussion about its status as IMT subtype. Furthermore, the newly detected alterations of the RTK/PI3K/AKT pathway expand the molecular landscape of IMTs and provide potential therapeutic targets.

Efficacy of tyrosine kinase inhibitors in patients with advanced or metastatic sarcomas after prior chemotherapy: A meta-analysis

BACKGROUND

Sarcoma is a heterogeneous malignancy arising from interstitial tissue. Anthracycline-based therapy is the first-line treatment recommended by guidelines for patients with locally advanced or metastatic unresectable sarcoma. Recently, targeted therapies, in particular tyrosine kinase inhibitors (TKIs), have made significant progress in the treatment of sarcoma, and their efficacy has been investigated in randomized controlled trials. The aim of this meta-analysis is to evaluate the efficacy of TKIs in patients with advanced or metastatic sarcoma who have previously received chemotherapy.

METHODS

We completed a meta-analysis after conducting literature searches in PubMed, Embase, and Cochrane. The single-drug, placebo-controlled, randomized controlled clinical trials of TKIs in patients with advanced or progressive sarcoma who have previously received chemotherapy are available for inclusion in the study. The observation results were objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). The subgroup analysis was performed according to histological subtypes of sarcoma.

RESULTS

This study included 6 studies, including 1033 patients. The ORR (OR: 7.99, 95% CI: 3.62-19.61, P < .00001), DCR (OR: 2.54, 95% CI: 1.27-5.08, P = .009), PFS (HR: 0.46, 95% CI: 0.34-0.62, P < .00001), and OS (HR: 0.80, 95% CI: 0.67-0.96, P = .02) of patients treated with TKIs were better than those in the placebo group.

CONCLUSIONS

In patients with advanced sarcoma, TKIs have been shown to have advantages in terms of ORR, DCR and PFS and OS. Multi-targeted TKIs may be considered as one of the second-line treatment options for sarcoma patients who have received prior chemotherapy.

Clinical features, treatment strategies, and prognosis of epithelioid inflammatory myofibroblastic sarcoma in children: a multicenter experience

Background

Inflammatory myofibroblastic tumors (IMTs) are a spectrum of tumors that range in morphology and biological behavior from benign, intermediate, to apparently malignant and epithelioid inflammatory myofibroblastic sarcoma (EIMS) is one of the malignant subtypes. This study tried to provide experience and new ideas for treating this rare disease.

Methods

This study retrospectively analyzed and followed up 12 children with EIMS admitted to Beijing Children's Hospital, Baoding Children's Hospital, and Children's Hospital of Chongqing Medical University from August 2016 to May 2022.

Results

Of the 12 children, 7 were male and 5 were female, with a median age of 74.50 [interquartile range (IQR), 61.50-90.00] months. Of these patients, eight had a single lesion and four had multiple lesions. The maximum diameter of the single tumor foci was 19.30 cm, the full meridian of the multiple tumor foci target lesions was 32.67 cm, and the median maximum tumor size was 11.99 (IQR, 7.80-15.70) cm. The site of disease was the abdominopelvic cavity in eight cases, the thoracic cavity in two cases, the maxillofacial region in one case, and the larynx in one case. The clinical manifestations were predominantly elevated body temperature (n=8). There was one case of ROS1 fusion mutation and nine cases of ALK fusion mutation. Of the 12 children, 6 were biopsied at the initial diagnosis and 6 were surgically treated. Follow-up treatment included preoperative neoadjuvant chemotherapy (n=4), peritoneal thermal perfusion therapy (n=2), targeted therapy (n=3), postoperative chemotherapy (n=5), and radiotherapy (n=3). The follow-up time was 14.50 (IQR, 10.50-31.50) months, with eight cases of tumor-free survival, two cases of death, and two cases of loss of follow-up.

Conclusions

EIMS in children is extremely rare and clinically aggressive. The clinical presentation is nonspecific, and the initial diagnosis of the tumor is often large. Mutations in the ALK gene are common in EIMS. Surgery is the mainstay of EIMS treatment, and patients benefit from a multidisciplinary combination that includes targeted therapies, with long-term prognosis remaining subject to ongoing follow-up.

Mediastinal epithelioid inflammatory myofibroblastic sarcoma with the EML4-ALK fusion: A case report and literature review

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive subtype of inflammatory myofibroblastic tumour which rarely affects the chest cavity. We, for the first time, report a case of mediastinal EIMS with the EML4-ALK fusion. A young woman presented to our hospital with cough, chest tightness and shortness of breath. Computed tomography (CT) showed a mixed attenuation soft-tissue mass in the right middle and upper mediastinum. Negative results were obtained from bronchoscopy forceps biopsy and endobronchial ultrasound-guided transbronchial fine needle aspiration. CT-guided percutaneous biopsy was finally performed. However, due to the rapidly progressed EIMS that compressed the trachea and right main bronchus, the patient died of respiratory failure 1 day before diagnosis. EIMS progresses rapidly, and an early diagnosis is important. For mediastinal EIMS, CT-guided percutaneous biopsy may be useful. Next-generation sequencing of blood may be instructive to EIMS patients who are intolerant to invasive biopsy.

Update of Diagnosis and Targeted Therapy for ALK+ Inflammation Myofibroblastic Tumor

OPINION STATEMENT: Inflammatory myofibroblastic tumor (IMT), characterized by intermediate malignancy and a propensity for recurrence, has presented a formidable clinical challenge in diagnosis and treatment. Its pathological characteristics may resemble other neoplasms or reactive lesions, and the treatment was limited, taking chemotherapies as the only option for those inoperable. However, discovering anaplastic lymphoma kinase (ALK) protein expression in approximately 50% of IMT cases has shed light on a new diagnostic approach and application of targeted therapies. With the previous success of combating ALK+ non-small-cell lung cancers with ALK tyrosine kinase inhibitors (TKIs), crizotinib, a first-generation ALK-TKI, was officially approved by the U.S. Food and Drug Administration in 2020, to treat unresectable ALK+ IMT. After the approval of crizotinib, other ALK-TKIs, such as ceritinib, alectinib, brigatinib, and lorlatinib, have proven their efficacy on ALK+ IMT with sporadic case reports. The sequential treatments of targeted therapies in may provide the insight into the choice of ALK-TKIs in different lines of treatment for unresectable ALK+ IMT.

Epithelioid Inflammatory Myofibroblastic Sarcoma With Poor Response to Crizotinib: A Case Report

Introduction

Epithelioid type inflammatory myofibroblastic sarcoma (EIMS) is a subtype of inflammatory myofibroblastic tumor (IMT). It consists of round or epithelioid cells, and almost all types of EIMS contain rearrangements of the anaplastic lymphoma kinase (ALK) gene.

Case presentation

We describe a 20-year-old female presenting with abdominal pain and a rapidly growing intraabdominal mass who underwent surgical tumor resection. She was diagnosed with EIMS. ALK and ki-67 expressions were detected in immunohistochemistry assessment. She was started with Crizotinib 200 mg twice a day, and chemotherapy was also initiated due to the recurrence of the disease 4 months after the initial treatment. She was unresponsive to all the medical regimens and died in 8 months.

Conclusion

Approach to patients with EIMS is really challenging in terms of both diagnosis and treatment. Patients with combined surgical and non-surgical treatment regimen were seen to have a more favorable outcome in some EIMS cases. Therefore, it is essential to implement a multidisciplinary approach to diagnose and treat patients suspicious of EIMS.

Inflammatory myofibroblastic tumors: recent progress and future of targeted therapy

An inflammatory myofibroblastic tumor is a rare component of bone and soft-tissue sarcomas that has distinct pathological features as a lymphoplasmacytic inflammatory infiltrate. As is the case for other non-small round cell sarcomas, surgical resection remains the standard treatment strategy for inflammatory myofibroblastic tumors, but recurrence is possible. Concerning systemic therapy, the available data for conventional chemotherapy (such as those of doxorubicin-based regimens) are limited, and case reports of anti-inflammatory inflammatory myofibroblastic tumor treatments describe some degree of symptom relief and efficacy against tumor progression. However, as more information about cancer genomics accumulates, the potential for molecularly targeted therapies for inflammatory myofibroblastic tumors has become more promising. Approximately half of inflammatory myofibroblastic tumors harbor anaplastic lymphoma kinase (ALK) fusion genes, and the other half could have potentially targetable fusion genes or mutations such as ROS1, NTRK and RET; case reports demonstrating the clinical efficacy of treatments targeted to inflammatory myofibroblastic tumor have been published, as have several prospective clinical trials. Few drugs are approved for the treatment of inflammatory myofibroblastic tumor, and most of them were approved for tumor-agnostic indications. Drugs that could be used for pediatric indications and dosing in inflammatory myofibroblastic tumor have also not been established. To provide effective targeted therapy for rare diseases such as inflammatory myofibroblastic tumor, it is necessary to obtain clinical evidence by designing and performing clinical trials and to find a path toward regulatory approval.

Epithelioid inflammatory myofibroblastic sarcoma: a case report and brief literature review

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare variant of the inflammatory myofibroblastic tumor, characterized by more aggressive clinical course and nuclear membrane staining of anaplastic lymphoma kinase (ALK) with ALK rearrangement. An elderly male came to the clinic because of an accidental abdominal mass. Abdominal and pelvic enhanced CT revealed a tumor apparently orginated from mesenchymal tissue. Subsequently, the abdominal mass and multiple organ resection was performed, and the mass was pathologically confirmed as EIMS. The patient developed Clavien-Dindo Grade III postoperative complications and was discharged after his condition improved. He received doxorubicin monotherapy after operation, but only one cycle was administered due to severe vomiting. The follow-up of 5 months after operation showed no evidence of recurrence. Given the rarity of EIMS, and ALk inhibitors have a long and robust effect on patients with ALK gene tumors, it is very important for clinicians to be familiar with the clinicopathological features of EIMS, which will contribute to the accurate diagnosis of EIMS and reduce misdiagnosis.

ALK fusions in the pan-cancer setting: another tumor-agnostic target?

Anaplastic lymphoma kinase (ALK) alterations (activating mutations, amplifications, and fusions/rearrangements) occur in ~3.3% of cancers. ALK fusions/rearrangements are discerned in >50% of inflammatory myofibroblastic tumors (IMTs) and anaplastic large cell lymphomas (ALCLs), but only in ~0.2% of other cancers outside of non-small cell lung cancer (NSCLC), a rate that may be below the viability threshold of even large-scale treatment trials. Five ALK inhibitors -alectinib, brigatinib, ceritinb, crizotinib, and lorlatinib-are FDA approved for ALK-aberrant NSCLCs, and crizotinib is also approved for ALK-aberrant IMTs and ALCL, including in children. Herein, we review the pharmacologic tractability of ALK alterations, focusing beyond NSCLC. Importantly, the hallmark of approved indications is the presence of ALK fusions/rearrangements, and response rates of ~50-85%. Moreover, there are numerous reports of ALK inhibitor activity in multiple solid and hematologic tumors (e.g., histiocytosis, leiomyosarcoma, lymphoma, myeloma, and colorectal, neuroendocrine, ovarian, pancreatic, renal, and thyroid cancer) bearing ALK fusions/rearrangements. Many reports used crizotinib or alectinib, but each of the approved ALK inhibitors have shown activity. ALK inhibitor activity is also seen in neuroblastoma, which bear ALK mutations (rather than fusions/rearrangements), but response rates are lower (~10-20%). Current data suggests that ALK inhibitors have tissue-agnostic activity in neoplasms bearing ALK fusions/rearrangements.

RNA binding protein PRRC2B mediates translation of specific mRNAs and regulates cell cycle progression

Accumulating evidence suggests that posttranscriptional control of gene expression, including RNA splicing, transport, modification, translation and degradation, primarily relies on RNA binding proteins (RBPs). However, the functions of many RBPs remain understudied. Here, we characterized the function of a novel RBP, Proline-Rich Coiled-coil 2B (PRRC2B). Through photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation and sequencing (PAR-CLIP-seq), we identified transcriptome-wide CU- or GA-rich PRRC2B binding sites near the translation initiation codon on a specific cohort of mRNAs in HEK293T cells. These mRNAs, including oncogenes and cell cycle regulators such as CCND2 (cyclin D2), exhibited decreased translation upon PRRC2B knockdown as revealed by polysome-associated RNA-seq, resulting in reduced G1/S phase transition and cell proliferation. Antisense oligonucleotides blocking PRRC2B interactions with CCND2 mRNA decreased its translation, thus inhibiting G1/S transition and cell proliferation. Mechanistically, PRRC2B interactome analysis revealed RNA-independent interactions with eukaryotic translation initiation factors 3 (eIF3) and 4G2 (eIF4G2). The interaction with translation initiation factors is essential for PRRC2B function since the eIF3/eIF4G2-interacting defective mutant, unlike wild-type PRRC2B, failed to rescue the translation deficiency or cell proliferation inhibition caused by PRRC2B knockdown. Altogether, our findings reveal that PRRC2B is essential for efficiently translating specific proteins required for cell cycle progression and cell proliferation.

Case report: Epithelioid inflammatory myofibroblastic sarcoma treated with an ALK TKI ensartinib

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive variant of inflammatory myofibroblastic tumor (IMT) and has a poor prognosis. EIMS is characterized by epithelioid morphology, neutrophilic infiltrate and specific fusion partners of anaplastic lymphoma kinase (ALK). Despite no standard therapy for EIMS, ALK tyrosine kinase inhibitors (TKIs) are recommended for these tumors. The present case describes an abdominal mass that presented in a 31-year-old male. The patient suffered from recurrence and multiple metastases 2 months after surgery. Ensartinib was administered and RANBP2-ALK fusion was detected. A partial response has been observed for 4 months and there has been no recurrence. This study provided a successful case with sustained response of targeted therapy.

Hallmarks of Anaplastic Lymphoma Kinase Inhibitors with Its Quick Emergence of Drug Resistance

Anaplastic lymphoma kinase (ALK) is one of the most popular targets for anticancer therapies. In the past decade, the use of anaplastic lymphoma tyrosine kinase inhibitors (ALK-TKIs), including crizotinib and ceritinib, has been a reliable and standard options for patients with lung cancer, particularly for patients with nonsmall cell lung carcinoma. ALK-targeted therapies initially benefit the patients, yet, resistance eventually occurs. Therefore, resistance mechanisms of ALK-TKIs and the solutions have become a formidable challenge in the development of ALK inhibitors. In this review, based on the knowledge of reported ALK inhibitors, we illustrated the crystal structures of ALK, summarized the resistance mechanisms of ALK-targeted drugs, and proposed potential therapeutic strategies to prevent or overcome the resistance.

Inflammatory Myofibroblastic Tumour: State of the Art

Simple Summary

Among sarcomas, which are rare cancers, inflammatory myofibroblastic tumors are extremely rare. Unlike other subtypes, this is a largely oncogene-driven neoplasia, and early gene rearrangement identification is important for accurate advanced stage treatment. In this manuscript, we review the clinicopathologic characteristics of this ultra-rare entity, as well as the current treatment landscape, with a particular focus on opportunities provided by tyrosine kinase inhibitors (TKIs).

Abstract

An inflammatory myofibroblastic tumor (IMT) is a neoplasm composed of myofibroblastic and fibroblastic spindle cells accompanied by inflammatory cells, including lymphocytes and eosinophils. It is an ultra-rare tumor, the optimal management of which remains to be defined. Surgery is the treatment of choice for localized tumors. The treatment of advanced disease is not precisely defined. Chemotherapy regimens result in an overall response rate of approximately 50% based on retrospective data. The latest pathophysiological data highlight the role played by tyrosine kinase fusion genes in IMT proliferation. Anaplast lymphoma kinase (ALK) oncogenic activation mechanisms have been characterized in approximately 80% of IMTs. In this context, data regarding targeted therapies are most important. The aims of this article are to review the latest published data on the use of systematic therapy, particularly the use of molecular targeted therapy, and to publish an additional case of an IMT with Ran-binding protein 2 (RANPB2)-ALK fusion showing a long response to a tyrosine kinase inhibitor.