Talimogene laherparepvec pseudolymphomatous reaction mimicking metastatic melanoma

Talimogene laherparepvec (T-VEC) as a treatment for melanoma: A systematic review

Background and aimsMelanoma now presents an average risk of 1 in 50 in the Western world. Talimogene laherparepvec (T-VEC), an FDAapproved oncolytic virus derived from Herpes Simplex Virus type 1 (HSV-1), has proven effective in reducing morbidity and mortality from melanoma but causes adverse effects like chills, fever, exhaustion, and injection site discomfort. Research focuses on combining T-VEC with immune checkpoint inhibitors, such as pembrolizumab, to enhance its efficacy and broaden its application.MethodsA systematic search was conducted using PubMed, Scopus, Web of Science, Google Scholar, and ProMED, adhering to PRISMA guidelines. Results were tabulated and analyzed.ResultsThis review included 15 studies comprising nine cohorts, four case reports, a case series, and a randomized control trial, involving 779 melanoma patients in stages IIIB to IV, 58% of whom were male with a mean age of 65 years. Treatment duration with T-VEC averaged 35.07 weeks, with dosages ranging from 10^6 to 10^8 PFU/ml. The intervention yielded a mean DRR of 41.87% and an ORR of 62.2%. The most common side effect was chills, affecting 21.69% of participants. Pyrexia was reported by 20.41% of participants, followed by influenzalike illness (14.89%).ConclusionT-VEC effectively improves ORR and DRR in melanoma patients. However, further research is needed on combination therapy prospects and its adverse effects.

Immunotherapy for keratinocyte cancers. Part II: Identification and management of cutaneous side effects of immunotherapy treatments

Keratinocytic cancers (KCs), specifically cutaneous squamous cell and basal cell carcinomas, can respond to topical, intralesional, or systemic immunotherapies, but cutaneous adverse events (CAEs) may occur. Understanding these risks, early recognition of these CAEs, and effective treatment may enable patients to continue their anticancer immunotherapies without dose impact. Immune checkpoint inhibitor-related CAEs after KCs can have multiple clinical presentations, with specific observed types including psoriasis and bullous pemphigoid. Cutaneous toxicities can require biopsies to confirm the diagnosis, especially in patients who are not responsive to topical or oral steroids, since the selection of biologic drugs depends on accurate diagnosis. Different types of CAEs from immune checkpoint inhibitors have been associated with different oncologic outcomes in various primary cancer types, and this remains to be determined for KC patients. CAE characterization and management after immune checkpoint inhibitors in KC patients is a rapidly growing field that needs specific and prospective studies.

Clinical and molecular overview of immunotherapeutic approaches for malignant skin melanoma: Past, present and future

Traditional therapeutic approaches for malignant melanoma, have proved to be limited and/or ineffective, especially with respect to their role in improving patient survival and tumor recurrence. In this regard, immunotherapy has been demonstrated to be a promising therapeutic alternative, boosting antitumor responses through the modulation of cell signaling pathways involved in the effector mechanisms of the immune system, particularly, the so-called "immunological checkpoints". Clinical studies on the efficacy and safety of immunotherapeutic regimens, alone or in combination with other antitumor approaches, have increased dramatically in recent decades, with very encouraging results. Hence, this review will discuss the current immunotherapeutic regimens used to treat malignant melanoma, as well as the molecular and cellular mechanisms involved. In addition, current clinical studies that have investigated the use, efficacy, and adverse events of immunotherapy in melanoma will also be discussed.

Histopathological and immunological spectrum in response evaluation of talimogene laherparepvec treatment and correlation with durable response in patients with cutaneous melanoma

Talimogene laherparepvec (T-VEC) is an intralesional oncolytic virotherapy for patients with irresectable stage III-IVM1a cutaneous melanoma. Although this treatment is considered to mainly act through T cell-mediated mechanisms, prominent numbers of plasma cells after T-VEC treatment have been described. The aim was to investigate how often these plasma cells were present, whether they were relevant in the response to treatment, and if these or other histopathological features were associated with durable response to treatment. Histopathological (granulomas, perineural inflammation, etc.) and immunological features [e.g. B cells/plasma cells (CD20/CD138) and T cells (CD3,CD4,CD8)] were scored and correlated with durable tumor response [i.e. complete response (CR) persisting beyond 6 months after treatment]. Plasmacellular infiltrate was examined with next-generation sequencing and immunohistochemistry (IgG, IgM, IgA, and IgD). Plasma cells were present in all T-VEC injected biopsies from 25 patients with melanoma taken at 3-5 months after starting treatment. In patients with a durable response ( n = 12), angiocentric features and granulomas were more frequently identified compared with patients without a (durable) response ( n = 13); 75% versus 29% for angiocentric features ( P = 0.015) and 58% versus 15% for granulomas ( P = 0.041). There was a class switch of IgM to IgG with skewing to certain dominant Ig heavy chain clonotypes. An angiocentric granulomatous pattern in T-VEC injected melanoma lesions was associated with a durable CR (>6 months). Plasma cells are probably a relevant feature in the mechanism of response but were not associated with durable response.