Treatment of recurrent mucosal melanoma of the oral cavity with topical imiquimod and pembrolizumab achieves complete histopathologic remission

Recent progress in topical and transdermal approaches for melanoma treatment

The global incidence of melanoma, the most lethal form of skin cancer, continues to escalate, emphasizing the urgent need for more effective therapeutic strategies. This review assesses the latest advancements in topical and transdermal drug delivery systems, positioning them as promising alternatives. These systems allow for the direct application of therapeutic agents to tumor sites, enhancing drug effectiveness, improving patient compliance, and reducing systemic toxicity. Specifically, innovations such as nanoparticles, microneedles, and vesicular systems are explored for their potential to optimize topical and localized drug delivery. By incorporating a graphical overview of these drug delivery vehicles, we visually underscore their roles in enhancing therapeutic outcomes across various treatment categories such as chemotherapy, immunotherapy, phototherapy, phytotherapy, and targeted therapy. This article critically evaluates recent breakthroughs, addresses the current challenges faced by researchers, and explores the future directions of topical and transdermal approaches in melanoma management. By presenting a summary of the latest research and predicting future trends, this review aims to inform ongoing developments and encourage further innovation in strategies for treating melanoma.

Melanoma In Situ of the Hard Palate

Mucosal melanoma of the oral cavity is rare and highly aggressive, thought to represent less than 1% of melanomas. Within this subgroup, melanoma in situ has been rarely described. We describe the case of a 54-year-old male with history of tobacco use presented with extensive pigmented changes to the hard and soft palate. Biopsy demonstrated melanoma in situ. Mucosal surgical resection was performed with all peripheral epithelial margins involved and negative deep margins. After extensive multidisciplinary discussion, remaining mucosal margins were re-resected to the teeth and posteriorly onto the soft palate. Deep margins remained negative with melanoma in situ still present peripherally. The patient is routinely surveilled without evidence of recurrence. Oral cavity melanoma in situ has been rarely described. The treatment of choice is surgical excision, ranging from wide local excision to composite resections, with consideration given to medical adjuncts. This unique entity should be considered in pigmented oral abnormalities.

Pilot clinical trial of neoadjuvant toll-like receptor 7 agonist (Imiquimod) immunotherapy in early-stage oral squamous cell carcinoma

Background

There is no neoadjuvant immunotherapy for early-stage oral cancer patients. We report a single-arm, open-label, pilot clinical trial assessing the efficacy and safety of topical toll-like receptor-7 (TLR-7) agonist, imiquimod, utilized in a neoadjuvant setting in early-stage oral squamous cell carcinoma (OSCC).

Methods

The primary endpoint is reduction in tumor cell counts assessed by quantitative multiplex immunofluorescence and the immune-related pathologic response. The secondary endpoint is safety.

Results

60% of patients experienced a 50% reduction or greater in tumor cell count post-treatment (95% CI = 32% to 84%). Similarly, 60% of patients had immune-related major pathologic response (irMPR) with two complete pathologic responses, and 40% had partial response (PR) with the percent residual viable tumor ranging from 25% to 65%. An increase in functional helper and cytotoxic T-cells significantly contributed to a reduction in tumor (R=0.54 and 0.55, respectively). The treatment was well tolerated with the application site mucositis being the most common adverse event (grades 1-3), and no grade 4 life-threatening event. The median follow-up time was 17 months (95% CI = 16 months - not reached), and one-year recurrence-free survival was 93% of evaluable patients.

Conclusion

Neoadjuvant imiquimod immunotherapy could be safe and promising regimen for early-stage oral cancer.

Trial registration

ClinicalTrials.gov, Identifier NCT04883645.

Nanomaterials augmented bioeffects of ultrasound in cancer immunotherapy

Immunotherapy as a milestone in cancer treatment has made great strides in the past decade, but it is still limited by low immune response rates and immune-related adverse events. Utilizing bioeffects of ultrasound to enhance tumor immunotherapy has attracted more and more attention, including sonothermal, sonomechanical, sonodynamic and sonopiezoelectric immunotherapy. Moreover, the emergence of nanomaterials has further improved the efficacy of ultrasound mediated immunotherapy. However, most of the summaries in this field are about a single aspect of the biological effects of ultrasound, which is not comprehensive and complete currently. This review proposes the recent progress of nanomaterials augmented bioeffects of ultrasound in cancer immunotherapy. The concept of immunotherapy and the application of bioeffects of ultrasound in cancer immunotherapy are initially introduced. Then, according to different bioeffects of ultrasound, the representative paradigms of nanomaterial augmented sono-immunotherapy are described, and their mechanisms are discussed. Finally, the challenges and application prospects of nanomaterial augmented ultrasound mediated cancer immunotherapy are discussed in depth, hoping to pave the way for cancer immunotherapy and promote the clinical translation of ultrasound mediated cancer immunotherapy through the reasonable combination of nanomaterials augmented ultrasonic bioeffects.

An Alternative Device for the Topical Treatment of Oral Cancer: Development and Ex-Vivo Evaluation of Imiquimod-Loaded Polysaccharides Formulations

The topical use of imiquimod (IMQ), a non-specific immune response modifier, showed to be a promising therapeutic option for the early-stage treatment of some type of oral cancer, even when performed with a formulation (Aldara®) developed and approved for skin application. The aim of this work was the development of buccal formulations for the topical administration of IMQ with improved mucosal retention and reduced trans-mucosal permeation when compared to the reference formulation. Three different hydrogels based on carboxymethyl chitosan (CMChit), sodium alginate (A), and xanthan gum (X) in different combinations were prepared, and the loading of imiquimod was successfully performed by using a micellar formulation based on d-α-tocopheril polyethylene glycol 100 succinate (TPGS). Except for CMChit formulation, in all the other cases, the performance in vitro on the mucosa resulted comparable to the commercial formulation, despite the drug loading being 50-fold lower. Converting the gels in films did not modify the IMQ accumulated with respect to the correspondent gel formulation but produced as a positive effect a significant reduction in the amount permeated. Compared to the commercial formulation, this reduction was significant (p < 0.01) in the case of X film, resulting in an improvement of the retained/permeated ratio from 1 to 5.44. Mucoadhesion evaluation showed similar behavior when comparing the developed gels and the commercial formulation, and an excellent bioadhesion was observed for the films.