Intratumoral and Combination Therapy in Melanoma and Other Skin Cancers

Design and one-pot synthesis of new substituted pyrrolo[1,2-a]thieno[3,2-e]pyrimidine as potential antitumor agents: in vitro and in vivo studies

A new efficient and versatile one-pot three-component synthesis of substituted pyrrolo[1,2-a]thieno[3,2-e]pyrimidine derivatives has been developed. It is based on a multistep cascade reaction from 2-aminothiophenes and 2-hydroxy-4-oxobut-2-enoic acids, and derivatives of cyanoacetic acid catalyzed by diisopropylethylamine. As a result, novel pyrrolo[1,2-a]thieno[3,2-e]pyrimidine derivatives (21 compounds) were synthesized in a mild reaction conditions with a high yield. The structures of the developed compounds were confirmed by NMR and elemental analysis. The influence of electron-withdrawing or electron-donor substituents on the antitumor activity of the developed compounds has been identified. In vitro screening analysis of 21 compounds revealed six lead candidates (12aa, 12dc, 12hc, 12ic, 12lb, and 12mb) that demonstrated the most significant antitumor activity against B16-F10, 4T1 and CT26 cells. Necrosis/apoptosis assay showed that apoptosis was the predominant mechanism of cell death. Molecular docking analysis revealed several potential targets for tested compounds, i.e. phosphatidylinositol 5-phosphate 4-kinase (PI5P4K2C), proto-oncogene serine/threonine-protein kinase (Pim-1), nicotinamide phosphoribosyltransferase (NAMPT) and dihydrofolate reductase (DHFR). The lead compound (12aa) can effectively induce cell apoptosis, possesses a high yield (98 %) and requires low-cost starting chemicals for its synthesis. In vivo experiments with melanoma-bearing mice confirmed that 12aa compound resulted in the significant tumor inhibition on 15 d after the therapy. In particular, tumor volume was ∼0.19 cm3 for 50 mg/kg versus ∼2.39 cm3 in case of untreated mice and tumor weight was ∼71.6 mg for 50 mg/kg versus ∼452.4 mg when considered untreated mice. Thus, our results demonstrated the high potential of the 12aa compound in the treatment of melanoma and can be recommended for further preclinical studies.

Intratumoral Immunotherapy: Is It Ready for Prime Time?

PURPOSE OF REVIEW

This review presents the rationale for intratumoral immunotherapy, technical considerations and safety. Clinical results from the latest trials are provided and discussed.

RECENT FINDINGS

Intratumoral immunotherapy is feasible and safe in a wide range of cancer histologies and locations, including lung and liver. Studies mainly focused on multi-metastatic patients, with some positive trials such as T-VEC in melanoma, but evidence of clinical benefit is still lacking. Recent results showed improved outcomes in patients with a low tumor burden. Intratumoral immunotherapy can lower systemic toxicities and boost local and systemic immune responses. Several studies have proven the feasibility, repeatability, and safety of this approach, with some promising results in clinical trials. The clinical benefit might be improved in patients with a low tumor burden. Future clinical trials should focus on adequate timing of treatment delivery during the course of the disease, particularly in the neoadjuvant setting.

Classic and new strategies for the treatment of advanced melanoma and non-melanoma skin cancer

Advanced melanoma and non-melanoma skin cancers (NMSCs) are burdened with a dismal prognosis. To improve the survival of these patients, studies on immunotherapy and target therapies in melanoma and NMSCs are rapidly increasing. BRAF and MEK inhibitors improve clinical outcomes, and anti-PD1 therapy demonstrates better results than chemotherapy or anti-CTLA4 therapy in terms of the survival of patients with advanced melanoma. In recent years, the combination therapy of nivolumab plus ipilimumab has gained ground in studies for its survival and response rate benefits in patients with advanced melanoma. In addition, neoadjuvant treatment for stages III and IV melanoma, either as monotherapy or combination therapy, has recently been discussed. Another promising strategy evaluated in recent studies is the triple combination of anti-PD-1/PD-L1 immunotherapy and anti-BRAF plus anti-MEK targeted therapy. On the contrary, in advanced and metastatic BCC, successful therapeutic strategies, such as vismodegib and sonidegib, are based on the inhibition of aberrant activation of the Hedgehog signaling pathway. In these patients, anti-PD-1 therapy with cemiplimab should be reserved as the second-line therapy in case of disease progression or poor response. In patients with locally advanced or metastatic SCC, who are not candidates for surgery or radiotherapy, anti-PD1 agents such as cemiplimab, pembrolizumab, and cosibelimab (CK-301) have shown significant results in terms of response rate. PD-1/PD-L1 inhibitors, such as avelumab, have also been used in Merkel carcinoma, achieving responses in half of the patients with advanced disease. The latest prospect emerging for MCC is the locoregional approach involving the injection of drugs that can stimulate the immune system. Two of the most promising molecules used in combination with immunotherapy are cavrotolimod (a Toll-like receptor 9 agonist) and a Toll-like receptor 7/8 agonist. Another area of study is cellular immunotherapy with natural killer cells stimulated with an IL-15 analog or CD4/CD8 cells stimulated with tumor neoantigens. Neoadjuvant treatment with cemiplimab in CSCCs and nivolumab in MCCs has shown promising results. Despite the successes of these new drugs, the new challenges ahead will be to select patients who will benefit from these treatments based on biomarkers and parameters of the tumor microenvironment.

Luteolin-Loaded Nanoparticles for the Treatment of Melanoma

Background and Purpose

Luteolin (LUT), a flavonoid found in various plants, has been reported to have potential therapeutic effects in melanoma. However, poor water solubility and low bioactivity have severely restricted the clinical application of LUT. Based on the high reactive oxygen species (ROS) levels in melanoma cells, we developed nanoparticles encapsulating LUT with the ROS-responsive material poly(propylene sulfide)-poly(ethylene glycol) (PPS-PEG) to enhance the water solubility of LUT, accelerate the release of LUT in melanoma cells, and further enhance its anti-melanoma effect, providing a viable solution for the application of LUT nano-delivery systems in melanoma therapy.

Methods

In this study, LUT-loaded nanoparticles were prepared with PPS-PEG and named as LUT-PPS-NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were applied to determine the size and morphology of LUT-PPS-NPs. In vitro studies were carried out to determine the uptake and mechanism of LUT-PPS-NPs by SK-MEL-28 melanoma cells. According to the CCK-8 assay, the cytotoxic effects of LUT-PPS-NPs on human skin fibroblasts (HSF) and SK-MEL-28 cells were assessed. Apoptosis assays, cell migration and invasion assays, and proliferation inhibition assays with low and normal density plating were also applied to test the in vitro anti-melanoma effect. Additionally, melanoma models were established utilizing BALB/c nude mice and initially evaluated the growth inhibitory impact following intratumoral injection of LUT-PPS-NPs.

Results

The size of LUT-PPS-NPs was 169.77 ± 7.33 nm with high drug loading (15.05 ± 0.07%). In vitro, cellular assays confirmed that LUT-PPS-NPs were efficiently internalized by SK-MEL-28 cells and showed low cytotoxicity against HSF. Moreover, LUT released from LUT-PPS-NPs significantly inhibited tumor cell proliferation, migration and invasion. Animal experiments showed that LUT-PPS-NPs inhibited tumor growth more than 2-fold compared with the LUT group.

Conclusion

In conclusion, the LUT-PPS-NPs developed in our study enhanced the anti-melanoma effect of LUT.

Immunotherapy for Nonmelanoma skin cancer: Facts and Hopes

Non-melanoma skin cancer (NMSC) is the most frequently diagnosed malignancy in humans, representing a broad range of cutaneous tumors. Keratinocyte carcinomas, including basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (CSCC), are the most common NMSCs. The incidence of BCC and CSCC are steadily increasing due to a progressively aging population, chronic exposure to ultraviolet radiation, and increased awareness with earlier diagnosis. Rarer NMSCs such as Merkel cell carcinoma (MCC) and cutaneous adnexal carcinomas (CACs) are also on the rise. Although the majority of NMSC tumors are localized at diagnosis and managed effectively with curative surgery and radiation, in rare cases with nodal and distant metastases, systemic therapy is often required. As our understanding of the immunologic characteristics of NMSCs has improved, effective treatment options have expanded with the development of immunotherapy. The U.S. Food and Drug Administration (FDA) recently approved several immune checkpoint inhibitors for the treatment of locally advanced and metastatic MCC, CSCC, and BCC. We review the emerging role of immunotherapy as the standard of care for several advanced NMSCs not amenable to surgery and/or radiation and underscore the need for considering clinical trials of novel strategies in patients when immunotherapy does not provide durable benefit. Finally, we explore the potential of neoadjuvant and adjuvant immunotherapy.

Emerging immunotherapeutic strategies for the treatment of breast cancer

Immunotherapy has resulted in unprecedented gains in long-term outcomes for many cancer types and has revolutionized the treatment landscape of solid tumor oncology. Checkpoint inhibition in combination with chemotherapy has proven to be effective for the treatment of a subset of advanced triple-negative breast cancer in the first-line setting. This initial success is likely just the tip of the iceberg as there is much that remains unknown about how to best harness the immune system as a therapeutic strategy in all breast cancer subtypes. Therefore, numerous ongoing studies are currently underway to evaluate the safety and efficacy of immunotherapy in breast cancer. In this review, we will discuss emerging immunotherapeutic strategies for breast cancer treatment including the following: (1) Intratumoral therapies, (2) Anti-tumor vaccines, (3) B-specific T-cell engagers, and (4) Chimeric antigen receptor T-cell therapy, and (5) Emerging systemic immunotherapy strategies. For each topic, we will review the existing preclinical and clinical literature, discuss ongoing clinical trials, and highlight future directions in the field.

Surgical Resection After Talimogene Laherparepvec for Melanoma: Persistent Fuorodeoxyglucose Avidity on Positron Emission Tomography Despite No Viable Disease

BACKGROUND

Talimogene laherparepvec (TVEC) is an injectable attenuated oncolytic herpes simplex virus (HSV-1) used in the treatment of loco regionally metastatic melanoma. Lesions managed by TVEC are generally considered unresectable at time of initiation of intralesional therapy; however, a subset of patients go on to have surgical resection of loco regionally controlled disease. We sought to review our experience with surgical excision of treated lesions to offer an insight into the radiologic correlate, treatment effect, and pathological findings of intralesional TVEC therapy.

METHODS

This is a retrospective descriptive case series of patients who underwent TVEC injection at Mayo Clinic, Rochester, MN, between October 2016 and July 2020. Institutional Institutional Review Board approval was obtained.

RESULTS

Twenty-one patients underwent intralesional TVEC, met inclusion criteria, and were included in this series. Seven went on to surgical excision of the injected lesions after an initial course of TVEC. Of those 7 patients, 4 had residual melanoma in the specimen on final pathology, while 3 had a complete pathologic response. All 3 patients who had no residual disease on pathology continued to have fluorodeoxyglucose (FDG) avidity on preoperative positron emission tomography scan of the excised lesions.

DISCUSSION

Despite ongoing FDG avidity on PET scan, patients who have well-controlled disease and stability over time of the injected lesions may benefit from surgical excision following a course of TVEC. This may render the patient clinically disease free and/or allow them a reprieve from TVEC treatment.

[Management of malignant wounds]

Malignant wounds arise either primary or secondary in the context of a malignant transformation of already existing wounds. A plethora of skin tumors, such as basal cell carcinoma, squamous cell carcinoma, melanoma, lymphoma as well as cutaneous metastases of other malignancies can ulcerate and be the cause of malignant wounds. Ulcerating tumors or metastases of the skin can however mimic chronic wounds from other causes and remain unrecognized over a longer period. In patients with chronic ulcerations, the correct and timely diagnosis is paramount. Based on this, the stage and disease-oriented treatment should be chosen in harmony with the wishes of the patient. In addition, general measures, such as atraumatic dressing changes to reduce pain and bleeding and the use of antiseptic dressing materials to prevent bacterial colonization and associated odors should be considered.