Efficacy and safety of ingenol mebutate gel in field treatment of actinic keratosis on full face, balding scalp, or approximately 250 cm2 on the chest: A phase 3 randomized controlled trial

Treatment of Actinic Keratosis: The Best Choice through an Observational Study

Actinic keratosis (AK) is a precancerous lesion that can progress to invasive squamous cell carcinoma if untreated. However, no gold standard treatment has been established. We aimed to investigate the management of AK by comparing the effectiveness and treatment duration of treatment modalities, including cryotherapy, imiquimod (IMQ), and photodynamic therapy (PDT). We reviewed the medical records of 316 patients diagnosed with AK at Seoul St. Mary’s Hospital from February 2015 to May 2020, and a total of 195 patients were included. The clearance rate was the highest in PDT, followed by cryotherapy and IMQ (82.4%, 71.2%, and 68.0%, respectively). The recurrence rate was the lowest in cryotherapy, followed by PDT and IMQ (3.5%, 6.7%, and 10.5%, respectively, p < 0.05). The average treatment duration was shortest with PDT, followed by IMQ and cryotherapy (5.5 weeks, 6.8 weeks, and 9.1 weeks, respectively, p < 0.05). The number of hospital visits was lowest for PDT, followed by cryotherapy and IMQ (1.8, 2.8, and 3.6, respectively, p < 0.05). PDT showed the highest clearance rate, a moderate recurrence rate, the shortest treatment duration, and the least number of visits, suggesting that PDT could be the first choice for treatment of AK. Considering the advantages as a topical agent, IMQ could also be a treatment option.

The Role of Ingenane Diterpenes in Cancer Therapy: From Bioactive Secondary Compounds to Small Molecules

Diterpenes are a class of critical taxonomic markers of the Euphorbiaceae family, representing small compounds (eg, molecules) with a wide range of biological activities and multi-target therapeutic potential. Diterpenes can exert different activities, including antitumor and multi-drug resistance-reversing activities, and antiviral, immunomodulatory, and anti-inflammatory effects, mainly due to their great structural diversity. In particular, one polycyclic skeleton has been highlighted: ingenane. Besides this natural diterpene, promising polycyclic skeletons may be submitted to chemical modification—by in silico approaches, chemical reactions, or biotransformation—putatively providing more active analogs (eg, ingenol derivatives), which are currently under pre-clinical investigation. This review outlines the current mechanisms of action and potential therapeutic implications of ingenol diterpenes as small cancer molecules.

Structural anatomy of Protein Kinase C C1 domain interactions with diacylglycerol and other agonists

Diacylglycerol (DAG) is a versatile lipid whose 1,2-sn-stereoisomer serves both as second messenger in signal transduction pathways that control vital cellular processes, and as metabolic precursor for downstream signaling lipids such as phosphatidic acid. Effector proteins translocate to available DAG pools in the membranes by using conserved homology 1 (C1) domains as DAG-sensing modules. Yet, how C1 domains recognize and capture DAG in the complex environment of a biological membrane has remained unresolved for the 40 years since the discovery of Protein Kinase C (PKC) as the first member of the DAG effector cohort. Herein, we report the high-resolution crystal structures of a C1 domain (C1B from PKCδ) complexed to DAG and to each of four potent PKC agonists that produce different biological readouts and that command intense therapeutic interest. This structural information details the mechanisms of stereospecific recognition of DAG by the C1 domains, the functional properties of the lipid-binding site, and the identities of the key residues required for the recognition and capture of DAG and exogenous agonists. Moreover, the structures of the five C1 domain complexes provide the high-resolution guides for the design of agents that modulate the activities of DAG effector proteins.

Patient-reported outcomes of topical therapies in actinic keratosis: A systematic review

Patients' perspectives on actinic keratosis treatments may have an impact on treatment adherence and, therefore, therapeutic outcomes. We performed a systematic review to assess patients' perspectives of topical, field‐directed treatments for actinic keratoses. A literature search was conducted, and 14 studies were identified encompassing 4433 patients. Only four studies were focused on face and/or scalp, which are the locations that typically impact patients' quality of life. Four studies were clinical trials. One study utilized a validated patient‐reported outcomes (PRO) instrument specifically developed for actinic keratosis. In general, treatment adherence and patient satisfaction were better with shorter‐duration treatment regimens such as ingenol mebutate gel. Imiquimod improved quality of life in one study but not in another. No data was available on topical piroxicam. The findings underscore the need for effective and well‐tolerated, short‐duration topical treatment for actinic keratosis.

Regenerative Wound Dressings for Skin Cancer

Skin cancer is considered the most prevalent cancer type globally, with a continuously increasing prevalence and mortality growth rate. Additionally, the high risk of recurrence makes skin cancer treatment among the most expensive of all cancers, with average costs estimated to double within 5 years. Although tumor excision is the most effective approach among the available strategies, surgical interventions could be disfiguring, requiring additional skin grafts for covering the defects. In this context, post-surgery management should involve the application of wound dressings for promoting skin regeneration and preventing tumor recurrence and microbial infections, which still represents a considerable clinical challenge. Therefore, this paper aims to provide an up-to-date overview regarding the current status of regenerative wound dressings for skin cancer therapy. Specifically, the recent discoveries in natural biocompounds as anti-cancer agents for skin cancer treatment and the most intensively studied biomaterials for bioactive wound dressing development will be described.

Efficacy Endpoints in Clinical Trials in Actinic Keratosis

Introduction

Actinic keratosis is regarded as a chronic disease of the skin and, although fluctuating, is chronically progressive. Approval of new products for the treatment of actinic keratosis requires the use of a standard methodology in clinical trials which emphasize complete clearance of all actinic keratoses in a treatment field in a defined time span and the evaluation of long-term efficacy in terms of recurrence rate among completely cleared patients.

Methods

Analysis of data from six previously published clinical trials in patients with actinic keratosis.

Results

There was poor agreement over a period of 1 month in the complete clearance endpoint. This variation in assessment renders recurrence in cleared patients invalid as the estimate of long-term efficacy. Furthermore, complete clearance was shown to depend heavily on the number of baseline actinic keratoses.

Conclusion

The main endpoints presently in use for the assessment of short- and long-term efficacy of actinic keratosis field-directed therapy, namely, complete clearance and recurrence rate, are obsolete and should be replaced by the percentage reduction in actinic keratosis count or the absolute actinic keratosis count.

Funding

LEO Pharma A/S.