Persistent complete response after single-agent sunitinib treatment in a case of TFE translocation positive relapsed metastatic pediatric renal cell carcinoma

High-throughput and targeted drug screens identify pharmacological candidates against MiT-translocation renal cell carcinoma

BACKGROUND

MiT-Renal Cell Carcinoma (RCC) is characterized by genomic translocations involving microphthalmia-associated transcription factor (MiT) family members TFE3, TFEB, or MITF. MiT-RCC represents a specific subtype of sporadic RCC that is predominantly seen in young patients and can present with heterogeneous histological features making diagnosis challenging. Moreover, the disease biology of this aggressive cancer is poorly understood and there is no accepted standard of care therapy for patients with advanced disease. Tumor-derived cell lines have been established from human TFE3-RCC providing useful models for preclinical studies.

METHODS

TFE3-RCC tumor derived cell lines and their tissues of origin were characterized by IHC and gene expression analyses. An unbiased high-throughput drug screen was performed to identify novel therapeutic agents for treatment of MiT-RCC. Potential therapeutic candidates were validated in in vitro and in vivo preclinical studies. Mechanistic assays were conducted to confirm the on-target effects of drugs.

RESULTS

The results of a high-throughput small molecule drug screen utilizing three TFE3-RCC tumor-derived cell lines identified five classes of agents with potential pharmacological efficacy, including inhibitors of phosphoinositide-3-kinase (PI3K) and mechanistic target of rapamycin (mTOR), and several additional agents, including the transcription inhibitor Mithramycin A. Upregulation of the cell surface marker GPNMB, a specific MiT transcriptional target, was confirmed in TFE3-RCC and evaluated as a therapeutic target using the GPNMB-targeted antibody-drug conjugate CDX-011. In vitro and in vivo preclinical studies demonstrated efficacy of the PI3K/mTOR inhibitor NVP-BGT226, Mithramycin A, and CDX-011 as potential therapeutic options for treating advanced MiT-RCC as single agents or in combination.

CONCLUSIONS

The results of the high-throughput drug screen and validation studies in TFE3-RCC tumor-derived cell lines have provided in vitro and in vivo preclinical data supporting the efficacy of the PI3K/mTOR inhibitor NVP-BGT226, the transcription inhibitor Mithramycin A, and GPNMB-targeted antibody-drug conjugate CDX-011 as potential therapeutic options for treating advanced MiT-RCC. The findings presented here should provide the basis for designing future clinical trials for patients with MiT-driven RCC.

Clear Cell Renal Cell Carcinoma, Diagnostic and Therapeutic Difficulties, Case Report and Literature Review

Nephroblastoma is the most common kidney tumour in children, constitutes about 85% of cases. Although renal cell carcinoma (RCC) is the second-most common kidney malignancy in children, it constitutes only about 2–6% of all cases. Currently, the basis of children’s RCC treatment is Umbrella Protocol of SIOP-RTSG, but, due to the rare diagnosis of this neoplasm in children, in difficult cases, treatment is based on the experience in adult patients with RCC. Nephrectomy improves prognosis and is usually performed at the first step of treatment. Acute kidney injury secondary to urolithiasis in a patient after nephrectomy due to RCC is a unique, very serious complication. Study design: We present a case of a 10-year-old boy with metastatic clear cell renal cell carcinoma (ccRCC) of the right kidney and an acute renal failure of the left kidney secondary to uric acid nephrolithiasis. Partial regression of the spread of ccRCC after 12.5-month treatment with sunitinib, followed by progression being observed and satisfactory effects and tolerance of nivolumab were observed later. Comorbidity of acute kidney injury during nephrolithiasis and ccRCC after nephrectomy in children is unique. Drugs used in the treatment clear cell carcinoma in adults (sunitinib and nivolumab), are also used in children with ccRCC.

The Use of Inhibitors of Tyrosine Kinase in Paediatric Haemato-Oncology-When and Why?

The fundamental pathophysiology of malignancies is dysregulation of the signalling pathways. Protein tyrosine kinases (PTKs) are among the enzymes which, if mutated, play a critical role in carcinogenesis. The best-studied rearrangement, which enhances PTK activity and causes atypical proliferation, is BCR-ABL1. Abnormal expression of PTKs has proven to play a significant role in the development of various malignancies, such as chronic myelogenous leukaemia, brain tumours, neuroblastoma, and gastrointestinal stromal tumours. The use of tyrosine kinase inhibitors (TKIs) is an outstanding example of successful target therapy. TKIs have been effectively applied in the adult oncology setting, but there is a need to establish TKIs’ importance in paediatric patients. Many years of research have allowed a significant improvement in the outcome of childhood cancers. However, there are still groups of patients who have a poor prognosis, where the intensification of chemotherapy could even cause death. TKIs are designed to target specific PTKs, which lead to the limitation of severe adverse effects and increase overall survival. These advances will hopefully allow new therapeutic approaches in paediatric haemato-oncology to emerge. In this review, we present an analysis of the current data on tyrosine kinase inhibitors in childhood cancers.

Characteristics and outcome of pediatric renal cell carcinoma patients registered in the International Society of Pediatric Oncology (SIOP) 93-01, 2001 and UK-IMPORT database: A report of the SIOP-Renal Tumor Study Group

In children, renal cell carcinoma (RCC) is rare. This study is the first report of pediatric patients with RCC registered by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Pediatric patients with histologically confirmed RCC, registered in SIOP 93-01, 2001 and UK-IMPORT databases, were included. Event-free survival (EFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Between 1993 and 2019, 122 pediatric patients with RCC were registered. Available detailed data (n = 111) revealed 56 localized, 30 regionally advanced, 25 metastatic and no bilateral cases. Histological classification according to World Health Organization 2004, including immunohistochemical and molecular testing for transcription factor E3 (TFE3) and/or EB (TFEB) translocation, was available for 65/122 patients. In this group, the most common histological subtypes were translocation type RCC (MiT-RCC) (36/64, 56.3%), papillary type (19/64, 29.7%) and clear cell type (4/64, 6.3%). One histological subtype was not reported. In the remaining 57 patients, translocation testing could not be performed, or TFE-cytogenetics and/or immunohistochemistry results were missing. In this group, the most common RCC histological subtypes were papillary type (21/47, 44.7%) and clear cell type (11/47, 23.4%). Ten histological subtypes were not reported. Estimated 5-year (5y) EFS and 5y OS of the total group was 70.5% (95% CI = 61.7%-80.6%) and 84.5% (95% CI = 77.5%-92.2%), respectively. Estimated 5y OS for localized, regionally advanced, and metastatic disease was 96.8%, 92.3%, and 45.6%, respectively. In conclusion, the registered pediatric patients with RCC showed a reasonable outcome. Survival was substantially lower for patients with metastatic disease. This descriptive study stresses the importance of full, prospective registration including TFE-testing.

Progress Update in Pediatric Renal Tumors

PURPOSE OF REVIEW

Pediatric renal tumors account for 7% of new cancer diagnoses in children. Here, we will review results from recently completed clinical trials informing the current standard of care and discuss targeted and immune therapies being explored for the treatment of high risk or relapsed/refractory pediatric renal malignancies.

RECENT FINDINGS

Cooperative group trials have continued to make improvements in the care of children with pediatric tumors. In particular, trials that standardize treatment of rare cancers (e.g., bilateral Wilms tumor) have improved outcomes significantly. We have seen improvements in event free and overall survival in recently completed clinical trials for many pediatric renal tumors. Still, there are subsets of rarer cancers where outcomes remain poor and new therapeutic strategies are needed. Future trials aim to balance treatment toxicity with treatment efficacy for those with excellent outcomes while identifying novel therapeutics for those with poor outcomes.

Pediatric and young adult renal cell carcinoma

Renal cell carcinoma (RCC) is rare in children but is the most common renal tumor in adults. Pediatric RCC has different clinical characteristics, histopathology, and treatment compared with adult disease. Databases were reviewed from inception to February 2020, identifying 32 publications pertaining to 350 patients under 27 years. Surgery is the cornerstone for cure in localized RCC. Lymph node dissection remains controversial. Conventional radiotherapy has no curative role in RCC; similarly, conventional chemotherapy has not proven to be effective in large cohorts. Pediatric metastatic RCC has a poor outlook. There are no published prospective studies demonstrating which adjuvant therapy could improve outcome. Sunitinib, a tyrosine kinase inhibitor, is recommended in this group despite limited evidence. This review provides an overview for pediatric RCC, including the evolving role of precision medicine.

A prospective study of pediatric and adolescent renal cell carcinoma: A report from the Children's Oncology Group AREN0321 study

BACKGROUND

To the authors' knowledge, AREN0321 is the first prospective clinical study of pediatric and adolescent renal cell carcinoma (RCC). Goals of the study included establishing epidemiological, treatment, and outcome data and confirming that patients with completely resected pediatric RCC, including lymph node-positive disease (N1), have a favorable prognosis without adjuvant therapy.

METHODS

From 2006 to 2012, patients aged <30 years with centrally reviewed pathology of RCC were enrolled prospectively.

RESULTS

A total of 68 patients were enrolled (39 of whom were male; median age of 13 years [range, 0.17-22.1 years]). Stage was classified according to the American Joint Committee on Cancer TNM stage seventh edition as stage I in 26 patients, stage II in 7 patients, stage III in 26 patients, and stage IV in 8 patients, and was not available in 1 patient. Sixty patients underwent resection of all known sites of disease, including 2 patients with stage IV disease. Surgery included radical nephrectomy (53 patients [81.5%]), partial nephrectomy (12 patients [18.5%]), and unknown (3 patients [4.4%]). Histology was TFE-associated RCC (translocation-type RCC; tRCC) in 40 patients, RCC not otherwise specified and/or other in 13 patients, papillary RCC in 9 patients, and renal medullary carcinoma (RMC) in 6 patients. Lymph node status was N0 in 21 patients, N1 in 21 patients (tRCC in 15 patients, RMC in 3 patients, papillary RCC in 2 patients, and not otherwise specified and/or other in 1 patient), and Nx in 26 patients. The 4-year event-free survival and overall survival rates were 80.2% (95% CI, 69.6%-90.9%) and 84.8% (95% CI, 75.2%-94.5%), respectively, overall and 87.5% (95% CI, 68.3%-100%) and 87.1% (95% CI, 67.6%-100%), respectively, for the 16 patients with N1M0 disease. Among patients presenting with metastases, 2 of 8 patients (2 of 5 patients with RMC) were alive (1 with disease) at the time of last follow-up, including 1 patient who was lost to follow-up (succinate dehydrogenase deficiency). The predominant RCC subtypes associated with mortality were tRCC and RMC.

CONCLUSIONS

Favorable short-term outcomes can be achieved without adjuvant therapy in children and adolescents with completely resected RCC, independent of lymph node status. A prospective study of patients with tRCC and RMC with M1 or recurrent disease is needed to optimize treatment.

Characteristics and Outcome of Children with Renal Cell Carcinoma: A Narrative Review

Pediatric renal cell carcinoma (RCC) is a rare type of kidney cancer, most commonly occurring in teenagers and young adolescents. Few relatively large series of pediatric RCC have been reported. Knowledge of clinical characteristics, outcome and treatment strategies are often based on the more frequently occurring adult types of RCC. However, published pediatric data suggest that clinical, molecular and histological characteristics of pediatric RCC differ from adult RCC. This paper summarizes reported series consisting of ≥10 RCC pediatric patients in order to create an up-to-date overview of the clinical and histopathological characteristics, treatment and outcome of pediatric RCC patients.

Treatment of advanced pediatric renal cell carcinoma

BACKGROUND

Pediatric renal cell carcinoma (pRCC) is the second most common renal malignancy of childhood; however, treatment data for advanced disease is lacking.

METHODS

A retrospective analysis of pRCC patients (age < 21 years at diagnosis) treated between 2000 and 2015 at Cincinnati Children's Hospital Medical Center was undertaken, with specific focus on medical therapies, accompanied by a detailed literature review.

RESULTS

Twenty-four patients (median age = 15 years) were identified; 11 were female. Past history of kidney pathology (4) and prior hematologic/oncologic diagnoses (5) were common associated findings. Translocation morphology RCC (tRCC) was the most common subtype (16; 64%), followed by papillary (6; 24%), clear cell renal cell carcinoma (ccRCC) (1), and chromophobe (1). The TNM stage distribution was I (8; 33%), II (2; 8%), III (3; 13%), and IV (11; 46%). Eleven patients with stage IV disease all had tRCC and received medicinal anticancer therapies, the most common being antiangiogenic (10), conventional chemotherapy (8), mTOR inhibition (7), and immunotherapy (3). Four patients also received small-port radiotherapy. The mean time to progression (TTP) was longest for axitinib (n = 2; TTP = 7.8 m; range 5.5-10 m) and sunitinib (n = 6; TTP = 4.7 m; range 0.3-12 m). Overall, 20 cases of pediatric RCC who received RCC-directed medicinal therapy with outcome data have been previously reported.

CONCLUSIONS

For patients with unresectable pRCC requiring systemic therapy, available data are scarce. Data herein support an increased TTP with antiangiogenic therapy in tRCC supporting a formal study of antiangiogenic therapies through multicooperative-group collaboration.

A study of axitinib, a VEGF receptor tyrosine kinase inhibitor, in children and adolescents with recurrent or refractory solid tumors: A Children's Oncology Group phase 1 and pilot consortium trial (ADVL1315)

BACKGROUND

Axitinib is an oral small molecule that inhibits receptor tyrosine kinases vascular endothelial growth factor receptors 1 to 3. A phase 1 and pharmacokinetic (PK) trial evaluating axitinib was conducted in children with refractory solid tumors.

METHODS

Axitinib was administered orally twice daily in continuous 28-day cycles. Dose levels (2.4 mg/m2 /dose and 3.2 mg/m2 /dose) were evaluated using a rolling 6 design. Serial PKs (cycle 1, days 1 and 8) and exploratory biomarkers were analyzed.

RESULTS

A total of 19 patients were enrolled; 1 patient was ineligible due to inadequate time having elapsed from prior therapy. The median age of the patients was 13.5 years (range, 5-17 years). Two of 5 patients who were treated at dose level 2 experienced dose-limiting toxicities (palmar-plantar erythryodysesthesia syndrome in 1 patient and intratumoral hemorrhage in 1 patient). Frequent (>20%) grade 1 to 2 toxicities during cycle 1 included anemia, anorexia, fatigue, diarrhea, nausea, and hypertension. Nonhematological toxicities of grade ≥3 in subsequent cycles included hypertension and elevated serum lipase. PK analysis demonstrated variability in axitinib exposure, the median time to peak plasma concentration was 2 hours, and the half-life ranged from 0.7 to 5.2 hours. Exposure and dose were not found to be significantly associated with hypertension. Five patients achieved stable disease for ≤6 cycles as their best response, including patients with malignant peripheral nerve sheath tumor (1 patient), Ewing sarcoma (1 patient), hepatocellular carcinoma (1 patient), and osteosarcoma (2 patients). One patient with alveolar soft part sarcoma achieved a partial response. Kidney injury biomarkers were found to be elevated at baseline; no trends were identified.

CONCLUSIONS

In children with refractory solid tumors, the maximum tolerated and recommended dose of axitinib appears to be 2.4 mg/m2 /dose, which provides PK exposures similar to those of adults.

Pediatric Patient With Renal Cell Carcinoma Treated by Successive Antiangiogenics Drugs: A Case Report and Review of the Literature

Antiangiogenic drugs are currently standard of care in adults with renal cell carcinoma (RCC), including translocation RCC. Although antitumor activity and toxicity profile are well known in adults, few data have been reported in children. Here we present the case of a patient diagnosed at 2 years old with a metastatic translocation RCC, consecutively treated with 5 tyrosine kinase inhibitors during 6 years. The antitumor activity and toxic effects are described, and a brief review of the literature is presented.

Renal Cell Carcinoma Associated with Xp11.2 Translocation/TFE3 Gene Fusions: Clinical Features, Treatments and Prognosis

To investigate the clinical characteristics, treatments and prognosis of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions (Xp11.2 tRCC), the epidemiological features and treatment results of 34 cases of Xp11.2 tRCC, which were diagnosed by immunohistochemistry staining of TFE3 and fluorescence in situ hybridization at our center, were retrospectively reviewed. The 34 patients included 21 females and 13 males aged 3 to 64 years (median age: 27 years). Four patients were children or adolescents (<18 years of age), and 26 patients were young or middle-aged adults (18-45 years). Radical nephrectomy was performed on 25 patients. Laparoscopic nephron-sparing surgery was performed on 9 patients who presented with an isolated mass with a small diameter (<7 cm) and well-defined boundary on computed tomography imaging. Postoperative staging showed that 25 cases (73.53%) were at stage I/II, while 9 cases (26.47%) were at stage III/IV. All stage I/II patients received a favorable prognosis with a three-year overall survival rate of 100%, including the patients who underwent laparoscopic nephron-sparing surgery. With the exception of 2 children, the other 7 stage III/IV patients died or developed recurrence with a median follow-up of 29 months. On univariate analysis, maximum diameter, adjuvant treatment, TNM stage, lymph node metastasis, inferior vena cava tumor thrombosis and tumor boundary were identified as statistically significant factors impacting survival (P<0.05). Multivariate analysis indicated that TNM stage and inferior vena cava tumor thrombosis were independent prognostic factors (P<0.05). In conclusion, Xp11.2 tRCC is a rare subtype of renal cell carcinoma that mainly occurs in young females. Nephron-sparing surgery was confirmed effective preliminarily in the treatment of small Xp11.2 tRCCs with clear rims. Advanced TNM stage and inferior vena cava tumor thrombosis were associated with poor prognosis.

The Tyrosine Kinase Inhibitor Sunitinib Affects Ovulation but Not Ovarian Reserve in Mouse: A Preclinical Study

The aim of the study was to evaluate ovarian toxicity of tyrosine kinase inhibitor (TKI) sunitinib, since only scarce data are available on gonadal function after this treatment. Six-week-old female mice received orally, once daily, vehicle or sunitinib (50 mg/kg/d) during 5 weeks. Fertility parameters were analyzed from ovulation to litter assessment. Sunitinib exposure significantly reduced (i) corpora lutea number per ovary (1.1 ± 0.38 in sunitinib group versus 4 ± 0.79 in control group, p<0.01) and (ii) serum Anti Müllerian hormone (AMH) levels in sunitinib treated mice (12.01 ± 1.16) compared to control mice (14.33 ± 0.87 ng/ml, p< 0.05). However, primordial and growing follicles numbers per ovary were not different in both groups. After treatment withdrawal, female mice in both groups were able to obtain litters. These data could be helpful to counsel clinicians and patients, when fertility preservation methods are discussed, before TKI treatment in girls and young women.

Characterization of adolescent and pediatric renal cell carcinoma: A report from the Children's Oncology Group study AREN03B2

BACKGROUND

The current study was conducted to characterize the epidemiology, histology, and radiographic features of as well as the surgical approach to pediatric and adolescent renal cell carcinoma (pRCC).

METHODS

pRCC cases prospectively enrolled on the Children's Oncology Group study AREN03B2 underwent central pathology, radiology, surgery, and oncology review.

RESULTS

As of June 2012, 120 of a total of 3250 patients enrolled on AREN03B2 (3.7%) were found to have unilateral RCC (median age, 12.9 years [range, 1.9-22.1 years]; 52.5% were female). Central review classified these as translocation morphology (56 patients), papillary (20 patients), renal medullary carcinoma (13 patients), chromophobe (4 patients), oncocytoma (1 patient), conventional clear cell (1 patient), and RCC not otherwise specified (25 patients). Lymph node (LN) involvement (N+) was found in 35 of 73 cases (47.9%) for which LNs were sampled, including 19 of 40 cases with primary tumors measuring <7 cm (47.5%). Using a size cutoff of 1 cm, imaging detection of LN involvement had a sensitivity of 57.14% (20 of 35 cases; 95% CI, 39.35%-73.68%) and a specificity of 94.59% (35 of 37 cases; 95% CI, 81.81%-99.34%). Distant metastases were present in 23 cases (19.2%). Initial surgery was radical nephrectomy in 88 patients (73.3%), nephron-sparing surgery in 18 patients (15.0%), and biopsy in 14 patients (11.7%). Compared with patients undergoing radical nephrectomy, those treated with nephron-sparing surgery were less likely to have LNs sampled (6 of 18 patients [33.3%] vs 65 of 88 patients [73.9%]; P = .002).

CONCLUSIONS

Translocation RCC is the most common form of pediatric and adolescent RCC. Lymph node disease is common and observed among patients with small primary tumors. Imaging has a high specificity but relatively low sensitivity for the detection of such lymph node disease. Failure to sample LNs results in incomplete staging and potentially inadequate disease control for younger patients with RCC.

Lessons learned from adult clinical experience to inform evaluations of VEGF pathway inhibitors in children with cancer

Agents targeting the vascular endothelial growth factor (VEGF) pathway have been studied in adults with cancer for nearly two decades. It is important to assess the lessons learned from this adult experience and to see how these lessons can help inform pediatric development of agents in this class. The benefit achieved from the use of VEGF pathway targeted agents for adult cancers has primarily been to delay for several months disease progression and less commonly time to death for conditions in which cure is not a reasonable expectation. VEGF pathway targeted agents have shown no efficacy when applied in the adjuvant setting. For adults with advanced cancer, prolongation of survival by 2-3 months is considered an important achievement in some settings. However, the primary goal of pediatric oncology clinical research is to identify treatments that allow children to be cured of their cancer and to grow to adulthood without treatment-induced limitations that lower their quality of survival. An important question for the pediatric oncology research community, pharmaceutical companies, and regulatory agencies to address in planning for future clinical trials is whether existing data support a role for VEGF pathway targeted agents in contributing to a therapeutic pathway to cure for children with cancer.

Ageing-related responses to antiangiogenic effects of sunitinib in atherosclerosis-prone mice

Antiangiogenic therapies in cancer exert their effects in the context of age-related comorbidities, which affect the entirety of the vascular system. Among those conditions, the impact of atherosclerosis is especially prevalent, but poorly understood, and not reflected in mouse models routinely used for testing antiangiogenic therapeutics. Our earlier work suggested that these obstacles can be overcome with the use of atherosclerosis-prone ApoE-/- mice harbouring syngeneic transplantable Lewis Lung Carcinoma (LLC). Here we report that, sunitinib, the clinically approved, antiangiogenic inhibitor impedes global tumor growth to a greater extent in aged then in young mice. This activity was coupled with changes in the tumor microenvironment, which in aged mice was characterized by pronounced hypoxia, reduction in microvascular density (MVD) and lower pericyte coverage, relative to young controls. We also detected soluble VEGR2 in plasma of sunitinib treated mice. Interestingly, sunitinib modulated tumor infiltration with bone marrow-derived cells (CD45+), recruitment of M2-like macrophages (CD163+) and activation of inflammatory pathways (phospho-STAT3) in a manner that was age-dependent. We suggest that age and atherosclerosis may alter the effects of sunitinib on the tumor microenvironment, and that these considerations may also apply more broadly to other forms of antiangiogenic treatment in cancer.

The preliminary experiences of translocation renal cell carcinoma and literature review

Xp11.2 translocation renal cell carcinoma (RCC) is rare and predominantly found in children and young adults. Because of the property of overexpressed transcription factor E3 (TFE3) fusion protein, immunohistochemical (IHC) staining with TFE3 antibody makes an excellent diagnostic tool. This study analyzed preliminary experiences of eight Xp11.2 translocation RCCs in our institution between 2007 and 2012. In four males and four females with a mean age of 28.4 years. Xp11.2 translocation RCCs were diagnosed. TFE3 IHC stain was positive in all tumor specimens. As the initial presentation, four patients suffered from abdominal pain, three cases had gross hematuria, and one case had hemoptysis caused by existing lung metastasis. The tumor was located in the right kidney (75%) with mean diameter of 5.85 ± 2.64 cm. Three cases (38%, 3/8) presented with lymph node metastasis at the time of diagnosis. In five cases (63%, 5/8), the initial diagnosis was Stage III and IV. Treatment included open surgery (one partial nephrectomy and five radical nephrectomies), cryoablation, immunotherapy, and target therapy. The mean follow-up time was 32 months. One patient died after 23.4 months of follow-up. The application of TFE3 IHC stain will improve the diagnostic accuracy for detecting XP11.2 translocation renal cell carcinoma. Surgery or cryoablation both had excellent prognosis in early stages. Although the disease is believed to be indolent, an increasingly aggressive clinical course should be kept in mind, especially for children and young adults.