Complete Response to Nivolumab in Recurrent/Metastatic HPV-Positive Head and Neck Squamous Cell Carcinoma Patient After Progressive Multifocal Leukoencephalopathy: A Case Report

In an immune-competent context nivolumab showed long-term benefit in overall survival in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC); however, in special cancer population such as these patients with immunodeficiency and viral infections, data on checkpoint inhibitors (ICI) activity are scant. Herein, we report a patient with a Human papilloma virus (HPV)-related oropharyngeal cancer (OPC) and CD4 lymphocytopenia. After a first-line treatment complete remission, the patient experienced Human Polyomavirus (JCV) infection in the brain. Consequently, to the recovery from progressive multifocal leukoencephalopathy (PML) the patient metastasized and was enrolled in a single-arm trial with nivolumab (EudraCT number: 2017-000562-30). A complete and durable response (more 3 years) was observed after 10 nivolumab injections Q2wks, interrupted for persistent drug related G2 diarrhea and a syndrome of inappropriate antidiuretic hormone secretion. We describe the circulating immune profile (before-, during-, and after nivolumab), consistent with the clinical history. Moreover, during nivolumab treatment, brain MRI evidenced the presence of small punctuate areas of contrast enhancement, reflecting a mild immune response in perivascular spaces. By cytofluorimetry, we observed that during JCV infection the CD4/CD8 ratio of the patient was under the normal values. After JCV infection recovery and before nivolumab treatment, CD4/CD8 ratio reached the normality threshold, even if the CD4+ T cell count remained largely under the normal values. During ICI, gene expression xCell analyses of circulating immune cells of the patient, showed a progressive normalization of the total immune profile, with significant boost in CD4+ and CD8+ T cells and a reduction in NK T, comparable to the circulating immune profile of reference tumor-free HNSCC patients. The present case supports the activity of ICI in a population of special cancer patients; whether JCV and HPV infections (alone or together) might have a possible role as immune booster(s), require further investigations.

Innovative therapeutic concepts of progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is an opportunistic viral disease of the brain—caused by human polyomavirus 2. It affects patients whose immune system is compromised by a corresponding underlying disease or by drugs. Patients with an underlying lymphoproliferative disease have the worst prognosis with a mortality rate of up to 90%. Several therapeutic strategies have been proposed but failed to show any benefit so far. Therefore, the primary therapeutic strategy aims to reconstitute the impaired immune system to generate an effective endogenous antiviral response. Recently, anti-PD-1 antibodies and application of allogeneic virus-specific T cells demonstrated promising effects on the outcome in individual PML patients. This article aims to provide a detailed overview of the literature with a focus on these two treatment approaches.

Cerebral lesions in hematological malignancies: a case report

Background Progressive multifocal leukoencephalopathy is a rare central nervous system disease, resulting from reactivation of latent John Cunningham virus. Monoclonal antibodies have recently become a relevant risk factor for developing progressive multifocal leukoencephalopathy. Case summary We report the case of a 62-year-old Caucasian man who was admitted to our department in June 2020 because of right homonymous hemianopia. Magnetic resonance imaging findings were first interpreted as an intracranial relapsed lymphoma, so brain biopsy was performed, but no neoplastic cell was found. Histological sample only showed a large number of macrophages. The patient came back to our attention because of the worsening of neurological symptoms. A second magnetic resonance imaging showed widespread lesions suggestive of a demyelinating process. John Cunningham virus DNA was detected by polymerase chain reaction assay of the cerebrospinal fluid (over 9 million units/μL). The patient was treated supportively, but the outcome was poor. Discussion A multidisciplinary assessment should be performed for differential diagnosis of cerebral lesions in hematologic malignancies. Progressive multifocal leukoencephalopathy should be suspected in cases of subacute neurological symptoms and imaging findings consistent with it, especially if the patient received immunosuppressive or immunomodulatory drugs.