Excessive toxicity of cabozantinib in a phase II study in patients with recurrent and/or metastatic salivary gland cancer

Clinical trials for patients with salivary gland cancers: A systematic review of worldwide registers and an evaluation of current challenges

BACKGROUND

Clinical trials (CT) are crucial for generating scientific evidence and improving clinical outcomes, but they can be challenging in the context of rare cancers. Salivary gland cancers (SGC) are rare and heterogeneous tumors, without standard-of-care approved systemic therapies. We analyzed completed and ongoing CTs to assess the current state of clinical research activity in the field.

METHODS

ClinicalTrials.gov, WHO-ICTRP, HealthCanadaCT were searched for antineoplastic pharmacological and interventional CT involving patients with SGC from the trials database creation until August 6th, 2024. CT characteristics and status were collected.

RESULTS

134 clinical trials met inclusion criteria. Of these, 78 % were sponsored by non-industry entities. 49 % were conducted at only one site, and 61 % at up to five centers. Only 25 trials (19 %) were multinational, being 15 industry-sponsored, a significantly higher proportion compared to non-industry-sponsored trials(p < 0.01). 16 % CTs were umbrella or basket, and 6 % were randomized, again predominantly industry-sponsored(p < 0.01). Regarding SGC-specific trials, 32 % were open to all patients with SGC, regardless of specific histology. Patients with adenoid cystic, salivary duct, and mucoepidermoid carcinoma had access to 92 %, 66 % and 62 % of trials, respectively. 88 % CT targeted palliative setting, and 38 % incorporated predictive biomarkers. Tyrosine kinase inhibitors were the most studied therapy(26 %), followed by immunotherapy(15 %), chemotherapy and antibody-drug conjugate(12 % each) and androgen-blockade(8 %), among others.

CONCLUSION

Clinical research for patients with SGC relies mainly in non-industry organisations, most of them limited to run trials in one to five sites, in a single country. Further collaboration between investigators is needed, as well as reconsidering inclusion criteria and trial designs.

Advances in Targeted and Systemic Therapy for Salivary Gland Carcinomas: Current Options and Future Directions

Salivary gland carcinomas (SGCs) represent a rare and heterogeneous group of malignancies accounting for 3-6% of all head and neck cancers. While surgical resection and radiotherapy remain the standard for locoregional control, systemic treatment is indicated for recurrent or metastatic disease. Advances in molecular profiling have identified actionable targets such as NTRK gene fusions, HER2, immune checkpoint regulators, androgen receptors, and RET receptors. These have facilitated the development of targeted therapies, including TRK inhibitors, HER2-directed agents, and androgen receptor modulators, as well as emerging combinations of immunotherapy and chemotherapy. Despite these advancements, challenges such as resistance mechanisms and limited therapeutic efficacy persist. Overall response rates remain relatively low across most systemic therapies, reflecting a persistent unmet clinical need. This review discusses the current landscape of treatment options and explores promising clinical trials and future directions to enhance outcomes for patients with SGCs.

The Adverse Impact of Tyrosine Kinase Inhibitors on Wound Healing and Repair

Tyrosine kinase inhibitors (TKIs) can treat various cancers, primarily through their antiangiogenic effects. However, as angiogenesis is crucial for successful wound healing, TKIs may adversely impact wound repair. This review analysed all 63 FDA-approved TKIs and identified evidence for wound healing and repair implications in 24 agents. The primary mechanism contributing to impaired wound healing appears to be the inhibition of vascular endothelial growth factor receptors, with secondary targets, such as epidermal growth factor receptors and platelet-derived growth factor receptors, potentially playing a role. Information from safety package inserts, preclinical studies, case reports and clinical trials suggests that these TKIs can cause delayed or impaired wound healing. The safety information generally recommends discontinuing treatment for at least one to 2 weeks before elective surgery and resuming treatment only after adequate wound healing has occurred. Neoadjuvant therapy with TKIs may be feasible if sufficient time is allowed between the cessation of the TKI and the onset of surgery. As the use of TKIs continues to increase, healthcare professionals should be aware of their potential impact on wound healing and take appropriate precautions to minimise the risk of wound-related complications.

Current landscape and future directions of therapeutic approaches for adenoid cystic carcinoma of the salivary glands (Review)

Adenoid cystic carcinoma (ACC) of the salivary glands is the second most common type of salivary gland cancer, and is characterized by a poor prognosis and an unclear pathology. The incidence of ACC is rare, as it accounts for 10-15% of all salivary gland tumors and affects mainly patients aged between 50 and 60 years. The annual incidence rate is estimated to be ~4.5 cases per 100,000 individuals. Due to its rarity and the use of contaminated cell lines in previous investigations, the precise etiological factors underlying ACC remain poorly understood. Current treatment modalities, typically involving surgery with or without postoperative radiotherapy, often prove unsatisfactory due to the potential for local recurrence and delayed distant metastases, which may manifest 3-5 years after treatment and constitute the primary failure of existing therapeutic approaches. The indolent growth pattern, along with perineural and perivascular invasion, is potentially responsible for the delayed onset of metastases. No effective systemic therapy has been established so far. Therefore, the management of ACC represents a significant therapeutic challenge. Exploring the molecular characteristics of ACC, including the reasons behind its propensity for perineural invasion and its potential correlation with the immune system, offers promising strategies for managing ACC and could open up novel pathways for future therapeutic interventions. Currently, the use of immunotherapy in ACC treatment has shown limited effectiveness. While the exact mechanism underlying the lack of response to immunotherapy in ACC remains unknown, the low levels of tumor-infiltrating lymphocytes in these tumors may contribute to this resistance. Therefore, identifying novel targets to enhance the immune response against tumor cells is essential. The present review provides an update on clinical studies and explores novel therapeutic targets that could be effective in the therapeutic management of ACC.

Adenoid cystic carcinoma: insights from molecular characterization and therapeutic advances

Adenoid cystic carcinoma (ACC) is a malignant tumor primarily originating from the salivary glands, capable of affecting multiple organs. Although ACC typically exhibits slow growth, it is notorious for its propensity for neural invasion, local recurrence, and distant metastasis, making it a particularly challenging cancer to treat. The complexity of ACC's histological and molecular features poses significant challenges to current treatment modalities, which often show limited effectiveness. Recent advancements in single-cell RNA-sequencing (scRNA-seq) have begun to unravel unprecedented insights into the heterogeneity and subpopulation diversity within ACC, revealing distinct cellular phenotypes and origins. This review delves into the intricate pathological and molecular characteristics of ACC, focusing on recent therapeutic advancements. We particularly emphasize the insights gained from scRNA-seq studies that shed light on the cellular landscape of ACC, underscoring its heterogeneity and pathobiology. Moreover, by integrating analyses from public databases, this review proposes novel perspectives for advancing treatment strategies in ACC. This review contributes to the academic understanding of ACC by proposing novel therapeutic approaches informed by cutting-edge molecular insights, paving the way for more effective, personalized therapeutic approaches for this challenging malignancy.

Vascular Endothelial Growth Factor Receptor Inhibitors for Recurrent or Metastatic Adenoid Cystic Carcinoma: A Systematic Review and Meta-Analysis

Importance

There is no systemic therapy for recurrent or metastatic adenoid cystic carcinoma (ACC) approved by the US Food and Drug Administration.

Objective

To examine the efficacy, safety, and tolerability of vascular endothelial growth factor receptor (VEGFR) inhibitors in recurrent or metastatic ACC.

Data Sources

PubMed, Embase, and Cochrane Library were systematically searched for studies of VEGFR inhibitors in recurrent or metastatic ACC from database inception to August 31, 2023.

Study Selection

Inclusion criteria were prospective clinical trials of recurrent or metastatic ACC treated with VEGFR inhibitors, reporting at least 1 outcome of interest specifically for ACC. Of 1963 identified studies, 17 (0.9%) met inclusion criteria.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline was followed to extract data. Data were pooled using a random-effects generalized linear mixed model with 95% CIs.

Main Outcomes and Measures

The primary efficacy outcome was best overall response to VEGFR inhibitors, including objective response, stable disease, or progressive disease (PD). Safety and tolerability outcomes included incidence of grade 3 or higher adverse events, rates of exit from trial due to PD or drug-related toxic effects, and dose reduction rate (DRR).

Results

A total of 17 studies comprising 560 patients with recurrent or metastatic ACC treated with 10 VEGFR inhibitors were included. The objective response rate was 6% (95% CI, 3%-12%; I2 = 71%) and stable disease was the most frequent best overall response (82%; 95% CI, 74%-87%; I2 = 67%). The 6-month disease control (defined as objective response and stable disease) rate was 54% (95% CI, 45%-62%; I2 = 52%). The rate of grade 3 or higher adverse events was 53% (95% CI, 42%-64%; I2 = 81%) and of DRR was 59% (95% CI, 40%-76%). Most patients (57%; 95% CI, 44%-70%; I2 = 83%) continued therapy until PD; 21% (95% CI, 15%-28%; I2 = 62%) of patients suspended therapy for toxic effects. In subgroup analysis by specific VEGFR inhibitor, the objective response rate was 14% (95% CI, 7%-25%; I2 = 0%), stable disease rate was 76% (95% CI, 63%-85%; I2 = 0%), proportion treated until PD was 61% (95% CI, 14%-94%; I2 = 94%), and DRR was 78% (95% CI, 66%-87%; I2 = 39%) with lenvatinib. Corresponding axitinib results were objective response rate of 8% (95% CI, 4%-15%; I2 = 0%) and stable disease rate of 85% (95% CI, 72%-92%; I2 = 69%), with 73% (95% CI, 63%-82%; I2 = 0%) of patients treated until PD, and the DRR was 22% (95% CI, 12%-38%; I2 = 77%). Rivoceranib had the highest objective response rate (24%; 95% CI, 7%-57%) but high heterogeneity among studies (I2 = 95%) and the lowest rate of patients who continued therapy until PD (35%; 95% CI, 20%-55%; I2 = 90%).

Conclusions and Relevance

This systematic review and meta-analysis found that VEGFR inhibitors were associated with high rates of disease stabilization in recurrent or metastatic ACC. Of 10 included VEGFR inhibitors, lenvatinib and axitinib were associated with the best combined and consistent efficacy, safety, and tolerability profiles, substantiating their inclusion in treatment guidelines.

Current diagnosis and treatment of salivary gland-type tumors of the lung

Salivary gland-type tumors of the lung are thought to originate from the submucosal exocrine glands of the large airways. Due to their rare occurrence, reports of their study are limited to small-scale or case reports. Therefore, daily clinical practices often require a search for previous reports. In the last 20 years, several genetic rearrangements have been identified, such as MYB::NF1B rearrangements in adenoid cystic carcinoma, CRTC1::MAML2 rearrangements in mucoepidermoid carcinoma, EWSR1::ATF1 rearrangements in hyalinizing clear cell carcinoma and rearrangements of the EWSR1 locus or FUS (TLS) locus in myoepithelioma and myoepithelial carcinoma. These molecular alterations have been useful in diagnosing these tumors, although they have not yet been linked to molecularly targeted therapies. The morphologic, immunophenotypic, and molecular characteristics of these tumors are similar to those of their counterparts of extrapulmonary origin, so clinical and radiologic differential diagnosis is required to distinguish between primary and metastatic disease of other primary sites. However, these molecular alterations can be useful in differentiating them from other primary lung cancer histologic types. The management of these tumors requires broad knowledge of the latest diagnostics, surgery, radiotherapy, bronchoscopic interventions, chemotherapy, immunotherapy as well as therapeutic agents in development, including molecularly targeted agents. This review provides a comprehensive overview of the current diagnosis and treatment of pulmonary salivary gland tumors, with a focus on adenoid cystic carcinoma and mucoepidermoid carcinoma, which are the two most common subtypes.

Prediction of cancer nanomedicines self-assembled from meta-synergistic drug pairs

Combination therapy is widely used in cancer medicine due to the benefits of drug synergy and the reduction of acquired resistance. To minimize emergent toxicities, nanomedicines containing drug combinations are being developed, and they have shown encouraging results. However, developing multi-drug loaded nanoparticles is highly complex and lacks predictability. Previously, it was shown that single drugs can self-assemble with near-infrared dye, IR783, to form cancer-targeted nanoparticles. A structure-based predictive model showed that only 4% of the drug space self-assembles with IR783. Here, we mapped the self-assembly outcomes of 77 small molecule drugs and drug pairs with IR783. We found that the small molecule drug space can be divided into five types, and type-1 drugs self-assemble with three out of four possible drug types that do not form stable nanoparticles. To predict the self-assembly outcome of any drug pair, we developed a machine learning model based on decision trees, which was trained and tested with F1-scores of 89.3% and 87.2%, respectively. We used literature text mining to capture drug pairs with biological synergy together with synergistic chemical self-assembly and generated a database with 1985 drug pairs for 70 cancers. We developed an online search tool to identify cancer-specific, meta-synergistic drug pairs (both chemical and biological synergism) and validated three different pairs in vitro. Lastly, we discovered a novel meta-synergistic pair, bortezomib-cabozantinib, which formed stable nanoparticles with improved biodistribution, efficacy, and reduced toxicity, even over single drugs, in an in vivo model of head and neck cancer.

Case of Tracheoesophageal Fistula Formation as a Rare Complication of Antiangiogenic Tyrosine Kinase Inhibitor Therapy for Metastatic Hepatocellular Carcinoma

Treatment with antiangiogenic tyrosine kinase inhibitors (TKIs) has shown longer overall survival (OS) and progression-free survival (PFS) than with placebo in patients with advanced hepatocellular carcinoma (HCC) who have previously received systemic therapy. Unfortunately, TKIs are associated with some rare adverse events such as tracheoesophageal fistula formation (TEF). The common risk factors for TEF formation include radiation therapy, prior instrumentation of the esophagus/airway, surgery, and esophagitis. We present a case of a 64-year-old man with a history of HCC who developed TEF after three months of treatment with cabozantinib. Patients experiencing these events require prompt termination of the antiangiogenic TKI. Urgent intervention should be pursued to prevent respiratory failure. Clinicians should be aware of the potential adverse effects of antiangiogenic TKIs, especially in high-risk patients.

Interaction of Some Amino-Nitrile Derivatives with Vascular Endothelial Growth Factor Receptor 1 (VEGFR1) Using a Theoretical Model

BACKGROUND

Some studies indicate that the angiogenesis process is related to vascular endothelial growth factor, which can interact with endothelial cell surface receptors (VEGF-R1, VEGF-R2, and VEGF-R3); this biochemical process and other factors result in the promotion and growth of new blood vessels under normal conditions. However, some studies indicate that this phenomenon could also occur in cancer cells. It is important to mention that some amino derivatives have been prepared as VEGF-R1 inhibitors; however, their interaction with VEGF-R1 is not clear, perhaps due to different experimental approaches or differences in their chemical structure.

OBJECTIVE

The aim of this study was to evaluate the theoretical interaction of several amino-nitrile derivatives (Compounds 1 to 38) with VEGF-R1.

METHODS

The theoretical interaction of amino-nitrile derivatives with VEGF-R1 was carried out using the 3hng protein as the theoretical model. In addition, cabozantinib, pazopanib, regorafenib, and sorafenib were used as controls in the DockingServer program.

RESULTS

The results showed different amino acid residues involved in the interaction of amino-nitrile derivatives with the 3hng protein surface compared with the controls. In addition, the inhibition constant (Ki) was lower for Compounds 10 and 34 than for cabozantinib. Other results show that Ki for Compounds 9, 10, 14, 27-29 and 34-36 was lower in comparison with pazopanib, regorafenib, and sorafenib.

CONCLUSIONS

All theoretical data suggest that amino-nitrile derivatives could produce changes in the growth of some cancer cell lines through VEGFR-1 inhibition. Therefore, these amino-nitrile derivatives could be a therapeutic alternative to treat some types of cancer.

Pembrolizumab and cabozantinib in recurrent metastatic head and neck squamous cell carcinoma: a phase 2 trial

Anti-programmed cell death protein 1 (PD-1) therapy is a standard of care in recurrent metastatic head and neck squamous cell carcinoma (RMHNSCC). Vascular endothelial growth factor inhibitors, including tyrosine kinase inhibitors, have immunomodulatory properties and have offered promising results when combined with anti-PD-1 agents. We conducted a phase 2, multicenter, single-arm trial of pembrolizumab and cabozantinib in patients with RMHNSCC who had Response Evaluation Criteria in Solid Tumors v.1.1 measurable disease and no contraindications to either agent. We assessed the primary end points of tolerability and overall response rate to the combination with secondary end points of progression-free survival and overall survival and performed correlative studies with PDL-1 and combined positive score, CD8+ T cell infiltration and tumor mutational burden. A total of 50 patients were screened and 36 were enrolled with 33 evaluable for response. The primary end point was met, with 17 out of 33 patients having a partial response (52%) and 13 (39%) stable disease with an overall clinical benefit rate of 91%. Median and 1-year overall survival were 22.3 months (95% confidence interval (CI) = 11.7-32.9) and 68.4% (95% CI = 45.1%-83.5%), respectively. Median and 1-year progression-free survival were 14.6 months (95% CI = 8.2-19.6) and 54% (95% CI = 31.5%-72%), respectively. Grade 3 or higher treatment-related adverse events included increased aspartate aminotransferase (n = 2, 5.6%). In 16 patients (44.4%), the dose of cabozantinib was reduced to 20 mg daily. The overall response rate correlated positively with baseline CD8+ T cell infiltration. There was no observed correlation between tumor mutational burden and clinical outcome. Pembrolizumab and cabozantinib were well tolerated and showed promising clinical activity in patients with RMHNSCC. Further investigation of similar combinations are needed in RMHNSCC. The trial is registered at ClinicalTrials.gov under registration no. NCT03468218 .

Systemic and Targeted Therapies in Adenoid Cystic Carcinoma

OPINION STATEMENT

Adenoid cystic carcinoma (ACC) is an often-indolent type of salivary gland cancer (SGC). A subset of patients develops progression or aggressive disease warranting systemic therapy in the recurrent/metastatic (R/M) setting. We recommend genomic testing for all patients with R/M disease to aid with prognostication and eligibility for potential experimental therapies. Here, we review the currently available treatment options (cytotoxic chemotherapies and vascular endothelial growth factor receptor (VEGFR)-targeting tyrosine kinase inhibitors (TKIs)). Based on limited data, we nominate regimens which may have more favorable efficacy profiles. Among the cytotoxic chemotherapies, several regimens are acceptable when incorporating a platinum agent. Among the VEGFR-targeting TKIs, lenvatinib and axitinib are the preferred options. Larger, randomized studies prioritizing combinations with mechanistic synergism are needed. Predictive biomarkers are critical, as there is currently little evidence to guide sequencing of available options for individual patients. Immunotherapy is an available option, but has been associated with only modest benefit in ACC. We go on to review other therapies that have been studied and nominate those with promise based on early clinical data.

The Therapeutic Landscape of Salivary Gland Malignancies-Where Are We Now?

Salivary gland malignancies (SGMs) account for less than 5% of new diagnoses in head and neck tumors. If feasible, surgery is the preferred treatment modality. Nevertheless, some malignancies have a tendency of recurrence, with possible distant metastasis. Alternative treatment strategies, such as primary radiation or chemotherapeutics, often present low response rates. As a result, there is an unmet need for novel therapeutic approaches. Nowadays, target-based therapies (e.g., small inhibitors and immunotherapy) are used by the medical oncologist for possible treatment of advanced SGMs. Based on recent published trials, some novel treatments may provide additional disease control for some patients. However, sample sizes are small, the general findings are unsatisfactory, and a lot of uncertainties remain to be elucidated. Nevertheless, research shows that patients do not benefit from blind administration of systemic treatments and therefore a more personalized approach is highly needed. The aim of this review paper is to summarize the most recent advances in the biological understanding and molecular pathways of salivary gland cancers, the association of these pathways with the current treatments used and their implications for more personalized targeted-based therapies.

Emerging tyrosine kinase inhibitors for head and neck cancer

INTRODUCTION

Conventional regimens for head and neck squamous cell carcinoma (HNSCC) are limited in efficacy and are associated with adverse toxicities. Food and Drug Administration (FDA) approved molecular targeting agents include the HER1 (EGFR)-directed monoclonal antibody cetuximab and the immune checkpoint inhibitors nivolumab and pembrolizumab. However, clinical benefit is only seen in roughly 15-20% of HNSCC patients treated with these agents. New molecular targeting agents are needed that either act with monotherapeutic activity against HNSCC tumors or enhance the activities of current therapies, particularly immunotherapy. Small-molecule tyrosine kinase inhibitors (TKIs) represent a viable option toward this goal.

AREAS COVERED

This review provides an update on TKIs currently under investigation in HNSCC. We focus our review on data obtained and trials underway in HNSCC, including salivary gland cancers and nasopharyngeal carcinomas, but excluding thyroid cancer and esophageal cancer.

EXPERT OPINION

While some emerging TKIs have shown clinical benefit, the positive effects have, largely, been modest. The design of clinical trials of TKIs has been hampered by a lack of understanding of biomarkers that can be used to define patient populations most likely to respond. Further preclinical and translational studies to define biomarkers of TKI response will be critically important.

Prognosis of adenoid cystic carcinoma in head and neck region treated with different regimens-A single-centre study

BACKGROUND

No study has evaluated the impact of regimen on recurrence, metastasis and survival in patients with adenoid cystic carcinoma (ACC). The present study aimed to compare the efficacy of radioactive seed implantation and other regimens in treating ACC, so as to investigate the clinical applicability of radioactive seed implantation and determine the indications for this regimen.

METHODS

A total of 188 patients with ACC in oromaxillofacial region were allocated to four groups according to the treatment regimen: group 1 was treated with a combination of surgery and ¹²⁵ I seed therapy, group 2 with a combination of surgery and external radiotherapy, group 3 with surgery, whereas group 4 was untreated. The Kaplan-Meier method was used to assess the survival rates, and the Cox regression analyses were used to identify the associated prognostic factors.

RESULTS

The overall survival rates of 188 patients and groups 1, 2, 3 and 4 were 85.7%, 75%, 68.2% and 37.5%, respectively. Cox regression analysis revealed that age, T stage, N stage and regimen were independent prognostic factors of survival. Amongst patients with primary ACC, the efficacy of radioactive seed implantation was higher in those with perineural invasion than in those without.

CONCLUSION

Patient age, T stage, N stage and regimen are independent prognostic factors of survival in patients with ACC. Patients treated with surgery combined with postoperative ¹²⁵ I seed radiotherapy have a higher overall survival rate, and those with perineural invasion are more suitable for radioactive seed implantation therapy.

Systemic therapy for salivary gland malignancy: current status and future perspectives

Salivary gland malignancies are rare neoplasms that have a broad histological spectrum and a variety of biologic behaviors. Salivary gland malignancies are known as chemo-resistant tumors, which render optimal treatment challenging. This review summarizes the role of systemic therapy for salivary gland malignancies. To date, the advantage of adding concurrent chemotherapy has remained undefined for both postoperative and inoperable locally advanced salivary gland malignancy patients undergoing radiotherapy. For recurrent/metastatic disease, local and/or systemic treatment options should be discussed in a multidisciplinary setting with consideration to both patient needs and tumor factors. For symptomatic patients or those who may compromise organ function, palliative systemic therapy can be a reasonable option based on the results of phase II studies. Platinum combination regimens as first-line therapy have been widely accepted. Personalized therapies have become established options, particularly for androgen receptor-positive, HER2-positive and NTRK fusion-positive salivary gland malignancies (i.e. androgen receptor and HER2 in salivary duct carcinoma and NTRK3 in secretory carcinoma). For patients with adenoid cystic carcinoma, multi-targeted tyrosine kinase inhibitors have also been developed. Anti-PD1 checkpoint inhibitors have shown limited activity to date. Investigation of active systemic treatments for salivary gland malignancy remains a significant unmet need. Future directions might include a more comprehensive genomic screening approach (usually next-generation sequencing-based) and combination strategies using immune checkpoint inhibitors. These are rare malignancies that require ongoing effort in the conduct of high-quality clinical trials.