Sensorineural Hearing Loss After Adoptive Cell Immunotherapy for Melanoma Using MART-1 Specific T Cells: A Case Report and Its Pathophysiology

Ototoxicity Review: A Growing Number of Non-Platinum-Based Chemo- and Immunotherapies

OBJECTIVE

To raise awareness of the growing list of non-platinum-based chemo- and immunotherapeutic agents that have been associated with ototoxicity and to introduce the possible mechanism of ototoxicity of these agents.

DATA SOURCES

PubMed, Embase, and Web of Science.

REVIEW METHODS

A systematic review was performed following the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses). PubMed, Embase, and Web of Science databases were searched for published reports of ototoxicity from non-platinum-based chemo- and immunotherapeutic agents in adult and pediatric patients. Therapies that utilized any platinum-based agent were excluded.

CONCLUSIONS

Ototoxicity from non-platinum-based chemo- and immunotherapies is an evolving problem. There were 54 reports-39 case reports and 15 cohort studies-documenting ototoxicity from 7 agents/combination therapies. Of these reports, 37 (69%) were published within the last 15 years (after 2005). No recovery of hearing was documented in 21 of 56 cases (38%). Pretreatment audiograms were uncommon (19/54 studies, 35%), despite documented ototoxic associations.

IMPLICATIONS FOR PRACTICE

There is a growing number of novel, ototoxic, non-platinum-based chemo- and immunotherapeutic agents with various potential mechanisms of action. Otolaryngologists will need to prioritize awareness of these agents. This growing list of agents, many of which have reversible effects, suggest a need for standardized ototoxicity monitor protocols so that appropriate and timely management options can be implemented.

Audiovestibular Toxicity Secondary to Immunotherapy: Case Series and Literature Review

Introduction

Audiovestibular toxicity secondary to immunotherapy has only rarely been reported in the literature. Herein, we examine our experience diagnosing and managing audiovestibular immune-related adverse events (irAEs) in patients undergoing immunotherapy.

Methods

Four patients who experienced irAEs were included. Demographics, immunotherapy regimen, diagnostic tests, treatment, and outcomes were recorded in a retrospective chart review.

Results

The cases of three patients with metastatic melanoma and one patient with metastatic renal cell carcinoma are presented. Hearing loss and tinnitus were the most common presenting symptoms. Immune checkpoint inhibitors (ICIs) were implicated in three cases and T-cell therapy in one case. Two of three patients (67%) treated with steroids had substantial improvements in hearing.

Conclusions

Audiovestibular irAEs are a rare complication of immunotherapy. Suspicion for symptoms including hearing loss, tinnitus, and/or vertigo should prompt an expedient referral to the otolaryngologist for evaluation, as symptoms may improve with corticosteroid use. Hearing and/or vestibular deficits can have a substantial impact on the quality of life for affected patients, but rehabilitation options do exist.

Tumor-infiltrating lymphocyte treatment for anti-PD-1-resistant metastatic lung cancer: a phase 1 trial

Adoptive cell therapy using tumor-infiltrating lymphocytes (TILs) has shown activity in melanoma, but has not been previously evaluated in metastatic non-small cell lung cancer. We conducted a single-arm open-label phase 1 trial ( NCT03215810 ) of TILs administered with nivolumab in 20 patients with advanced non-small cell lung cancer following initial progression on nivolumab monotherapy. The primary end point was safety and secondary end points included objective response rate, duration of response and T cell persistence. Autologous TILs were expanded ex vivo from minced tumors cultured with interleukin-2. Patients received cyclophosphamide and fludarabine lymphodepletion, TIL infusion and interleukin-2, followed by maintenance nivolumab. The end point of safety was met according to the prespecified criteria of ≤17% rate of severe toxicity (95% confidence interval, 3-29%). Of 13 evaluable patients, 3 had confirmed responses and 11 had reduction in tumor burden, with a median best change of 35%. Two patients achieved complete responses that were ongoing 1.5 years later. In exploratory analyses, we found T cells recognizing multiple types of cancer mutations were detected after TIL treatment and were enriched in responding patients. Neoantigen-reactive T cell clonotypes increased and persisted in peripheral blood after treatment. Cell therapy with autologous TILs is generally safe and clinically active and may constitute a new treatment strategy in metastatic lung cancer.

Industrializing engineered autologous T cells as medicines for solid tumours

Cell therapy is one of the fastest growing areas in the pharmaceutical industry, with considerable therapeutic potential. However, substantial challenges regarding the utility of these therapies will need to be addressed before they can become mainstream medicines with applicability similar to that of small molecules or monoclonal antibodies. Engineered T cells have achieved success in the treatment of blood cancers, with four chimeric antigen receptor (CAR)-T cell therapies now approved for the treatment of B cell malignancies based on their unprecedented efficacy in clinical trials. However, similar results have not yet been achieved in the treatment of the much larger patient population with solid tumours. For cell therapies to become mainstream medicines, they may need to offer transformational clinical effects for patients and be applicable in disease settings that remain unaddressed by simpler approaches. This Perspective provides an industry perspective on the progress achieved by engineered T cell therapies to date and the opportunities and current barriers for accessing broader patient populations, and discusses the solutions and new development strategies required to fully industrialize the therapeutic potential of engineered T cells as medicines.

Adoptive Cellular Therapy for Solid Tumors

Cancer immunotherapy tools include antibodies, vaccines, cytokines, oncolytic viruses, bispecific molecules, and cellular therapies. This review will focus on adoptive cellular therapy, which involves the isolation of a patient's own immune cells followed by their ex vivo expansion and reinfusion. The majority of adoptive cellular therapy strategies utilize T cells isolated from tumor or peripheral blood, but may utilize other immune cell subsets. T-cell therapies in the form of tumor-infiltrating lymphocytes, T-cell receptor T cells, and CAR T cells may act as "living drugs" as these infused cells expand, engraft, and persist in vivo, allowing adaptability over time and enabling durable remissions in subsets of patients. Adoptive cellular therapy has been less successful in the management of solid tumors because of poor homing, proliferation, and survival of transferred cells. Strategies are discussed, including expression of transgenes to address these hurdles. Additionally, advances in gene editing using CRISPR/Cas9 and similar technologies are described, which allow for clinically translatable gene-editing strategies to enhance the antitumor activity and to surmount the hostilities advanced by the host and the tumor. Finally, the common toxicities and approaches to mitigate these are reviewed.

Gene Augmentation and Editing to Improve TCR Engineered T Cell Therapy against Solid Tumors

Recent developments in gene engineering technologies have drastically improved the therapeutic treatment options for cancer patients. The use of effective chimeric antigen receptor T (CAR-T) cells and recombinant T cell receptor engineered T (rTCR-T) cells has entered the clinic for treatment of hematological malignancies with promising results. However, further fine-tuning, to improve functionality and safety, is necessary to apply these strategies for the treatment of solid tumors. The immunosuppressive microenvironment, the surrounding stroma, and the tumor heterogeneity often results in poor T cell reactivity, functionality, and a diminished infiltration rates, hampering the efficacy of the treatment. The focus of this review is on recent advances in rTCR-T cell therapy, to improve both functionality and safety, for potential treatment of solid tumors and provides an overview of ongoing clinical trials. Besides selection of the appropriate tumor associated antigen, efficient delivery of an optimized recombinant TCR transgene into the T cells, in combination with gene editing techniques eliminating the endogenous TCR expression and disrupting specific inhibitory pathways could improve adoptively transferred T cells. Armoring the rTCR-T cells with specific cytokines and/or chemokines and their receptors, or targeting the tumor stroma, can increase the infiltration rate of the immune cells within the solid tumors. On the other hand, clinical “off-tumor/on-target” toxicities are still a major potential risk and can lead to severe adverse events. Incorporation of safety switches in rTCR-T cells can guarantee additional safety. Recent clinical trials provide encouraging data and emphasize the relevance of gene therapy and gene editing tools for potential treatment of solid tumors.

Single Cell and Single Nucleus RNA-Seq Reveal Cellular Heterogeneity and Homeostatic Regulatory Networks in Adult Mouse Stria Vascularis

The stria vascularis (SV) generates the endocochlear potential (EP) in the inner ear and is necessary for proper hair cell mechanotransduction and hearing. While channels belonging to SV cell types are known to play crucial roles in EP generation, relatively little is known about gene regulatory networks that underlie the ability of the SV to generate and maintain the EP. Using single cell and single nucleus RNA-sequencing, we identify and validate known and rare cell populations in the SV. Furthermore, we establish a basis for understanding molecular mechanisms underlying SV function by identifying potential gene regulatory networks as well as druggable gene targets. Finally, we associate known deafness genes with adult SV cell types. This work establishes a basis for dissecting the genetic mechanisms underlying the role of the SV in hearing and will serve as a basis for designing therapeutic approaches to hearing loss related to SV dysfunction.