Functional studies of McSTE24, McCYP305a1, and McJHEH, three essential genes act in cantharidin biosynthesis in the blister beetle (Coleoptera: Meloidae).

Cantharidin is a toxic defensive substance secreted by most blister beetles when attacked. It has been used to treat many complex diseases since ancient times and has recently regained popularity as an anticancer agent. However, the detailed mechanism of the cantharidin biosynthesis has not been completely addressed. In this study, we cloned McSTE24 (encoding STE24 endopeptidase) from terpenoid backbone pathway, McCYP305a1 (encoding cytochrome P450, family 305) and McJHEH [encoding subfamily A, polypeptide 1 and juvenile hormone (JH) epoxide hydrolase] associated to JH synthesis/degradation in the blister beetle Mylabris cichorii (Linnaeus, 1758, Coleoptera: Meloidae). Expression pattern analyses across developmental stages in adult males revealed that the expressions of 3 transcripts were closely linked to cantharidin titer exclusively during the peak period of cantharidin synthesis (20-25 days old). In contrast, at other stages, these genes may primarily regulate different biological processes. When RNA interference with double-stranded RNA suppressed the expressions of the 3 genes individually, significant reductions in cantharidin production were observed in males and also in females following McJHEH knockdown, indicating that these 3 genes might primarily contribute to cantharidin biosynthesis in males, but not in females, while females could self-synthesis a small amount of cantharidin. These findings support the previously hypothesized sexual dimorphism in cantharidin biosynthesis during the adult phase. McCYP305a1 collaborates with its upstream gene McSTE24 in cantharidin biosynthesis, while McJHEH independently regulates cantharidin biosynthesis in males.

Cantharidin overcomes IL-2Rα signaling-mediated vorinostat resistance in cutaneous T-cell lymphoma through reactive oxygen species.

BACKGROUND: Vorinostat (SAHA) is a histone deacetylase inhibitor that has shown clinical efficacy against advanced cutaneous T-cell lymphoma (CTCL). However, only a subset of patients with CTCL (30-35%) respond to SAHA and the response is not always sustainable. Thus, understanding the mechanisms underlying evasive resistance in this cancer is an unmet medical need to improve the efficacy of current therapies. PURPOSE: This study aims to identify factors contributing to resistance against SAHA in CTCL and ways to mitigate it. METHODS AND RESULTS: In this study, we demonstrated that attenuated reactive oxygen species (ROS) induces the expression of interleukin (IL)-2Rα, one of the IL-2 receptors, which drives resistance to SAHA in CTCL. We also determined that cantharidin could overcome SAHA resistance to CTCL by blocking IL-2Rα-related signaling via ROS-dependent manner. Mechanistically, accelerated translation of IL-2Rα contributes to excessive IL-2Rα protein formation as a result of reduced ROS levels in SAHA-resistant CTCL. At the same time, amplified IL-2R signals are evidenced by strengthened interaction of IL-2Rß with IL-2Rγ and Janus kinase/signal transducer and activator of transcription molecules, and by increased expression of protein kinase B (AKT)/mTOR and mitogen-activated protein kinase signaling. Moreover, cantharidin, an active constituent of Mylabris used in traditional Chinese medicine, markedly increased ROS levels, and thereby restrained IL-2Rα translation, resulting in suppression of downstream pathways in SAHA-resistant cells. Cantharidin is also found to synergize with SAHA and triggers SAHA-resistant cell death via IL-2R signaling both in vitro and in vivo. CONCLUSION: Our study uncovers a novel molecular mechanism of acquired SAHA resistance and also suggests that using cantharidin is a potential approach to overcome CTCL therapy resistance. Our findings underlie the therapeutic potential of cantharidin in treating CTCL.

Bibliometric Analysis and Systemic Review of Cantharidin Research Worldwide.

BACKGROUND: Cantharidin (CTD), a natural toxic compound from blister beetle Mylabris, has been used for cancer treatment for millenary. CTD and its analogs have become mainstream adjuvant drugs with radiotherapy and chemotherapy in clinical applications. However, the detailed pharmacology mechanism of CTD was not fully elucidated. METHODS: Publications of CTD were collected from the Web of Science Core Collection database from 1991 to 2023 using CiteSpace, VOSviewer, and Scimago Graphica software. RESULTS: A total of 1,611 publications of CTD were mainly published in China and the United States. The University of Newcastle has published the most researches. Mcclusey, Adam, Sakoff, Jennette, and Zhang, Yalin had the most CTD publications with higher H. Notably, CTD researches were mainly published in Bioorganic & Medicinal Chemistry Letters and the Journal of Biological Chemistry. Cluster profile results revealed that protein phosphatase 2A (PP2A), human gallbladder carcinoma, Aidi injection, and cell apoptosis were the hotspots. Concentration on the pharmacology function of PP2A subunit regulation, hepatotoxicity, nephrotoxicity, and cardiotoxicity mechanism should be strengthened in the future. CONCLUSION: Bibliometric analysis combined with a systemic review of CTD research first revealed that PP2A and CTD analogs were the knowledge base of CTD, and PP2A subunit regulation and toxic mechanism could be the frontiers of CTD.

A Farnesyl Pyrophosphate Synthase Gene Is Expressed in Fat Body Regulates Cantharidin Synthesis in Male Epicauta impressicornis Blister Beetle.

Blister beetles of Epicauta impressicornis have attracted attention because they contain a large amount of cantharidin (CTD). To date, however, the synthesis and transfer of CTD in adults of E. impressicornis are largely unknown. Here, we showed that the larvae E. impressicornis are capable of synthesizing CTD and they consume CTD during pupation. Before sexual maturity, both male and female adults synthesized a small amount of CTD, while after sexual maturity, males produced larger amounts of CTD, but females did not. The newly synthesized CTD in males first appeared in the hemolymph and then accumulated in the reproductive system. During the mating, the males transferred CTD to the reproductive system of females. In addition, a farnesyl pyrophosphate synthase (FPPS) gene was identified in male E. impressicornis. RNA-seq analysis, quantitative RT-PCR, and RNA interference analyses were conducted to investigate expression patterns and the functional roles of E. impressicornis FPPS (EiFPPS). Our results indicate that EiFPPS is highly expressed in the fat body of males. Moreover, the knock-down of EiFPPS led to a significant decrease in CTD synthesis. The current study indicates that EiFPPS is expressed in the fat body to regulate CTD synthesis in male E. impressicornis blister beetles.

Covalent Binding of Reactive Anhydride of Cantharidin to Biological Amines.

Cantharidin is a terpenoid from coleoptera beetles. Cantharidin has been used to treat molluscum contagiosum and some types of tumors. Cantharidin is highly toxic, and cantharidin poisoning and fatal cases have been reported worldwide. The mechanisms underlying cantharidin-induced toxicity remain unclear. Cantharidin contains anhydride, which may react with biologic amines. This study aimed to examine the chemical reactivity of cantharidin toward nucleophiles and characterize adducts of cantharidin with biologic amines in vitro and in mice. Here two types of conjugates were formed in the incubation of cantharidin under physiologic conditions with free amino acids, a mimic peptide, or amine-containing compounds, respectively. Amide-type conjugates were produced by the binding of cantharidin anhydride with the primary amino group of biologic amines. Imide-type conjugates were generated from the dehydration and cyclization of amide-type conjugates. The structure of the conjugates was characterized by using high-resolution mass spectrometry. We introduced the 14N/15N and 79Br/81Br isotope signatures to confirm the formation of conjugates using L-(ε)15N-lysine, L-lysine-15N2, and bromine-tagged hydrazine, respectively. The structure of imide conjugate was also confirmed by nuclear magnetic resonance experiments. Furthermore, the amide and imide conjugates of cantharidin with amino acids or N-acetyl-lysine were detected in mouse liver and urine. Cantharidin was found to modify lysine residue proteins in mouse liver. Pan-cytochrome P450 inhibitor 1-aminobenzotriazole significantly increased the urine cantharidin-N-acetyl-lysine conjugates, whereas it decreased cantharidin metabolites. In summary, cantharidin anhydride can covalently bind to biologic amines nonenzymatically, which facilitates a better understanding of the role of nonenzymatic reactivity in cantharidin poisoning. SIGNIFICANCE STATEMENT: Anhydride moiety of cantharidin can covalently bind to the primary amino group of biological amines nonenzymatically. Amide and imide conjugates were generated after the covalent binding of cantharidin anhydride with the primary amino groups of amino acids, a mimic peptide, and protein lysine residues. The structure of conjugates was confirmed by 14N/15N and 79Br/81Br isotope signatures using isotope-tagged reagents and nuclear magnetic resonance experiments. This study will facilitate the understanding of the role of nonenzymatic reactivity in cantharidin poisoning.

Cantharidin: A Multiporpuse Beetlejuice.

Cantharidin is produced by beetles of two families, Meloidae (true blister beetles) and Oedemeridae (false blister beetles). Nevertheless, it is mainly members of the meloid family that have been widely studied in the traditional medicines and pharmacology of different cultures and countries. The meloids cantharidin's role is going to be reviewed in this paper, including the cantharidin discovery, its adaptative function, and worldwide uses. Finally, we recovered information on the implementation of this compound in South American civilizations in different therapeutic treatments as well as sexual stimulants and aphrodisiacs.

Network toxicology, molecular docking technology, and experimental verification revealed the mechanism of cantharidin-induced testicular injury in mice.

As a protein kinase inhibitor, cantharidin (CTD) exhibits antitumor activities. However, CTD is highly toxic, thereby limiting clinical applications. Moreover, relatively few studies have investigated CTD-induced reproductive toxicity, thus the underlying mechanism remains unclear. In this study, the toxic effects of CTD on mouse testis were confirmed in vivo and the potential mechanism was predicted by network toxicology (NT) and molecular docking technology. Proteins involved in the signaling pathways and core targets were verified. The results showed that different concentrations of CTD induced weight loss increased the testicular coefficient, and caused obvious pathological damage to testicular cells. The NT results showed that the main targets of CTD-induced testicular injury (TI) included AKT1, Caspase 3, Bcl-2, and Bax. The results of pathway enrichment analysis showed that CTD-induced TI was closely related to apoptosis and the PI3K/AKT and HIF-1 signaling pathways. Molecular docking methods confirmed high affinity between CTD and key targets. Western blot analysis showed that CTD inhibited expression of PI3K, AKT, and the anti-apoptotic protein Bcl-2, while promoting expression of the pro-apoptotic proteins Bax and Caspase 3. These results suggest that CTD-induced TI involves multiple targets and pathways, and the underlying mechanism was associated with inhibition of the apoptosis-related PI3K/AKT signaling pathway.

Analysis of cantharidin-induced kidney injury and the protective mechanism of resveratrol in mice determined by liquid chromatography/mass spectrometry-based metabonomics.

Cantharidin (CTD) is the main active component in the traditional Chinese medicine Mylabris and an effective anti-tumor agent. However, it is relatively toxic and exhibits nephrotoxicity, which limits its clinical use. However, its toxic mechanism is not clear. The toxic effects of CTD exposure on the kidney and the protective effect of resveratrol (RES) were studied in a mouse model, by determination of serum biochemical and renal antioxidant indicators, histopathological and ultrastructural observation, and metabonomics. After CTD exposure, serum uric acid, creatinine, and tissue oxidative stress indicators increased, and the renal glomerular and tubular epithelial cells showed clear pathological damage. Ultrastructure observation revealed marked mitochondrial swelling, endoplasmic reticulum dilation, and the presence of autophagy lysosomes in glomerular epithelial cells. RES ameliorated the renal injury induced by CTD. Metabonomics analysis indicated that CTD can induce apoptosis and oxidative damage in kidney cells, mainly by disrupting sphingolipid and glutathione metabolism, increasing sphingosine and sphingomyelin levels, and decreasing glutathione levels. RES counteracts these effects by regulating renal cell proliferation, the inflammatory response, oxidative stress, and apoptosis, by improving the levels of phosphatidylcholine (PC), LysoPC, and lysophosphatidyl glycerol in the glycerophospholipid metabolism pathway, thereby reducing CTD-induced nephrotoxicity. The mechanisms of CTD-induced renal injury and the protective effect of RES were revealed by metabonomics, providing a basis for evaluating clinical treatment regimens to reduce CTD-induced nephrotoxicity.

A novel approach combining network pharmacology and experimental validation to study the protective effect of ginsenoside Rb1 against cantharidin-induced hepatotoxicity in mice.

Cantharidin (CTD) is a widely used anticancer compound, but its clinical use is mainly limited due to hepatotoxicity. Ginsenoside Rb1 (GRb1) shows potential hepatoprotective effects. Nonetheless, the protective effect and underlying mechanism of GRb1 against CTD-induced hepatotoxicity in mice have not been investigated. This study aims to elucidate the effect and mechanism of GRb1 on CTD-induced hepatotoxicity using network pharmacology and in vivo experiments. Network pharmacology studies have shown that 263 targets were the main mechanisms by which GRb1 alleviates CTD-induced hepatotoxicity. KEGG enrichment analysis revealed that 75 hub genes were mainly enriched in TNF, IL-17 and apoptosis signalling pathways. Molecular docking analysis showed that GRb1 exhibited high affinity with Akt1, Tnf, Il6, Bcl2 and Caspase3. In addition, results from animal studies demonstrated that GRb1 could ameliorate CTD-induced hepatotoxicity by inhibiting protein expression of Caspase-3, Caspase-8, Bcl-2/Bax, GRP78, ATF6, ATF4, CHOP, IRE1α and PERK. This research revealed the mechanism of GRb1 against CTD-induced hepatotoxicity by inhibiting apoptosis and endoplasmic reticulum stress (ERS) and it may provide a scientific rationale for the potential use of GRb1 in the treatment of hepatotoxicity induced by CTD.

In vitro immune-depression and anti-inflammatory activities of cantharidin on gilthead seabream (Sparus aurata) leucocytes activated by λ-carrageenan.

Cantharidin is a natural compound with known therapeutic applications in humans. The aim of this study was to investigate the in vitro effects of cantharidin on gilthead seabream (Sparus aurata) head kidney leucocytes (HKL) stimulated with λ-carrageenan. HKLs were incubated for 24 h with cantharidin (0, 2.5 and 5 µg mL-1) and λ-carrageenan (0 and 1000 µg mL-1). The results showed that HKL viability only decreased by 15.2% after incubated with 5 µg mL-1 of cantharidin and λ-carrageenan. Cantharidin increased the peroxidase activity of HKLs only when incubated in combination with λ-carrageenan. Besides this, cantharidin inhibited the respiratory burst and phagocytic activities. Furthermore, cantharidin induced morphological changes in HKLs (apoptotic and vacuolization signs) that were enhanced when incubated with λ-carrageenan. Considering the analysis of the selected gene expression studied in HKLs [NF-κB subunits (rela, relb, crel, nfkb1, nfkb2), proinflammatory cytokines (il1b, tnfa), anti-inflammatory cytokines (il10, tgfb) and caspases (casp1, casp3, casp8, casp9)], although λ-carrageenan up-regulated the expression of the proinflammatory gene il1b, λ-carrageenan and cantharidin down-regulated its expression in HKLs. In addition, cantharidin up-regulated casp3 and casp9 expression. The casp3 and casp9 gene expression was down-regulated while casp1 gene expression was up-regulated in HKLs incubated with both cantharidin and λ-carrageenan. All the effects of cantharidin are related to its inhibitory effect on protein phosphatases, which induce apoptosis at long exposure times, and minimize the effects of λ-carrageenan. The present results provide detailed insight into the immune-depressive and anti-inflammatory properties of cantharidin on immune cells, which could be of interest to the aquaculture sector.

Lipidomics reveals serum lipid metabolism disorders in CTD-induced liver injury.

BACKGROUND: Cantharidin (CTD), the main toxic component of Mylabris, has been extensively used for tumor treatment in recent years. CTD-induced liver toxicity has attracted significant interest in clinic. METHODS: In this study, biochemical parameters and liver pathological changes were analyzed after CTD was administered to mice by gavage. Subsequently, a lipidomic approach was used to investigate serum lipid metabolism disorders, and the mechanism underlying CTD-induced liver injury in mice was explored. RESULTS: The results showed that the levels of TC and LDL-C were significantly increased after CTD intervention. Besides, pathological results showed inflammatory cell infiltration and hepatocyte necrosis in the liver. Furthermore, lipidomics found that a total of 18 lipid metabolites were increased and 40 were decreased, including LPC(20:4), LPC(20:3), PC(22:6e/2:0), PE(14:0e/21:2), PC(18:2e/22:6), glycerophospholipids, CE(16:0), CE(18:0) Cholesterol esters and TAG(12:0/12:0/22:3), TAG(16:1/16:2/20:4), TAG(18:1/18:1/20:0), TAG(16:2/18:2/18:2), TAG(18:0/18:0/20:0), TAG(13:1/19:0/19:0) glycerolipids. Metabolic pathway analysis found that glycerophospholipid, glycerol ester and glycosylphosphatidylinositol (GPI)-anchored biosynthetic metabolic pathways were dysregulated and the increase in PE caused by glycophoric metabololism and GPI may be the source of lipid metabolism disorders caused by CTD. Overall, the present study provided new insights into the mechanism of CTD-induced liver injury and increased drug safety during clinical application.

Application of cantharidin, retinoic acid cream and salicylic acidy in multiple palmoplantar warts.

OBJECTIVE: Multiple palmoplantar warts, caused by human papillomavirus (HPV) infection, were investigated for clinical efficacy using cantharidin, retinoic acid cream, and salicylic acid cream. METHODS: A total of 110 patients with multiple palmoplantar warts were enrolled. The experimental group (54 cases) received a 1:1:1 combination (CRS) of 0.25% cantharidin, 0.1% retinoic acid cream, and 5% salicylic acid, applied with pressurized encapsulation for 8 h every night, three times per week. The control group (56 cases) underwent conventional liquid nitrogen freezing. Monthly follow-ups assessed cure rate, effective rate, dermatological life quality index (DLQI), visual analog scale (VAS), and cost, with evaluations conducted after 3 months. RESULTS: The treatment group exhibited a cure rate of 85.19% and a total effective rate of 96.30%, surpassing the control group with rates of 39.29% and 51.79%, respectively (p < 0.05). The treatment group's DLQI score (1.84 ± 1.06) was significantly lower than the control group's score (6.04 ± 1.78) (p = 0.0005). Additionally, the treatment group's VAS score (1.84 ± 1.06) was notably lower than the control group's score (8.56 ± 1.07) (p < 0.0001). The treatment group's total cost (43.20 ± 2.85) was markedly lower than the control group's cost (206.38 ± 90.81), with a statistically significant difference (p < 0.0001). CONCLUSION: The combination of cantharidin, retinoic acid cream, and salicylic acid with local encapsulation is a safe, effective, economical, and convenient treatment method for multiple palmoplantar warts, exhibiting few side effects and showing promise.

Avoiding cantharidin through ionotropic receptors.

The discernment and aversion of noxious gustatory stimuli profoundly influence homeostasis maintenance and survival of fauna. Cantharidin, a purported aphrodisiac, is a monoterpenoid compound secreted by many species of blister beetle, particularly by the Spanish fly, Lytta vesicatoria. Although the various advantageous functions of cantharidin have been described, its taste analysis and toxic properties in animalshave been rarely explored. Our study using Drosophila melanogaster examines the taste properties of cantharidin along with its potential hazardous effect in the internal organs of animals. Here, we find that cantharidin activates bitter taste receptors. Our findings show that specific ionotropic receptors (IR7g, IR51b, and IR94f) in labellar bitter-sensing neurons, along with co-receptors IR25a and IR76b, are responsible for detecting cantharidin. By introducing the IR7g and IR51b in sweet and bitter neurons, naturally expressing IR76b and IR25a, we show that these genes are sufficient for cantharidin perception. Moreover, we witness the deleterious ramifications of cantharidin on survival and visceral integrities, shedding light on its hazardous effect.

Cantharidin.

Cantharidin is the toxic component of blister beetles of the genus Epicauta. Cantharidin is a potent vesicant which causes blisters, erosions, and ulcerations in the gastrointestinal and urinary tracts, and can cause myocardial necrosis. Blister beetles are found over most of North America and specifically contaminate alfalfa at harvest. History of alfalfa feeding, with colic, dysuria, hypocalcemia, and hypomagnesemia are suggestive of blister beetle toxicosis. Myocardial damage causes increased serum cardiac troponin 1. Tentative diagnosis can be made by finding the beetles in feed or ingesta. Definitive diagnosis requires detection of cantharidin in urine or gastric contents. Treatment involves ending exposure, decreasing absorption, controlling pain, using gastroprotectants, and fluids and electrolyte replacement. Prognosis is guarded to poor.

Design and synthesis of cantharidin derivative DCZ5418 as a TRIP13 inhibitor with anti-multiple myeloma activity in vitro and in vivo.

Natural product cantharidin can inhibit multiple myeloma cell growth in vitro, while serious adverse effects limited its clinical application. Therefore, the structural modification of cantharidin is needed. Herein, inspired by the structural similarity of the aliphatic endocyclic moiety in cantharidin and TRIP13 inhibitor DCZ0415, we designed and synthesized DCZ5418 and its nineteen derivatives. The molecular docking study indicated that DCZ5418 had a similar binding mode to TRIP13 protein as DCZ0415 while with a stronger docking score. Moreover, the bioassay studies of the MM-cells viability inhibition, TRIP13 protein binding affinity and enzyme inhibiting activity showed that DCZ5418 had good anti-MM activity in vitro and definite interaction with TRIP13 protein. The acute toxicity test of DCZ5418 showed less toxicity in vivo than cantharidin. Furthermore, DCZ5418 showed good anti-MM effects in vivo with a lower dose administration than DCZ0415 (15 mg/kg vs 25 mg/kg) on the tumor xenograft models. Thus, we obtained a new TRIP13 inhibitor DCZ5418 with improved safety and good activity in vivo, which provides a new example of lead optimization by using the structural fragments of natural products.

Cantharidin-induced toxic injury, oxidative stress, and autophagy attenuated by Astragalus polysaccharides in mouse testis.

Cantharidin (CTD) is a chemical constituent derived from Mylabris and has good antitumor effects, but its clinical use is restricted by its inherent toxicity. However, few researches have reported its reproductive toxicity and mechanisms. This study aims to assess CTD's toxicity on mouse testes and the protective effect of Astragalus polysaccharides (APS). Briefly, biochemical analysis, histopathology, transmission electron microscopy, immunohistochemistry, and Western blotting were used to evaluate the oxidative damage of mouse testicular tissue after exposure to CTD and treatment by APS. Our research suggests a dramatic decrease in testicular index and serum testosterone levels after CTD exposure. The testis showed obvious oxidative damage accompanied by an increase in mitochondrial autophagy, the Nfr2-Keap1 pathway was inhibited, and the blood-testis barrier was destroyed. Notably, these changes were significantly improved after APS treatment. The internal mechanisms of APS ameliorate CTD-induced testicular oxidative damage in mice may be closely connected to regulatory the Nrf2-Keap1 signaling pathway, restraining autophagy, and repairing the blood-testis barrier, providing theoretical support for further study on the reproductive toxicity mechanism of CTD and clinical treatments to ameliorate it.

Cantharidin and sodium fluoride attenuate the negative inotropic effects of carbachol in the isolated human atrium.

Carbachol, an agonist at muscarinic receptors, exerts a negative inotropic effect in human atrium. Carbachol can activate protein phosphatases (PP1 or PP2A). We hypothesized that cantharidin or sodium fluoride, inhibitors of PP1 and PP2A, may attenuate a negative inotropic effect of carbachol. During bypass-surgery trabeculae carneae of human atrial preparations (HAP) were obtained. These trabeculae were mounted in organ baths and electrically stimulated (1 Hz). Force of contraction was measured under isometric conditions. For comparison, we studied isolated electrically stimulated left atrial preparations (LA) from mice. Cantharidin (100 µM) and sodium fluoride (3 mM) increased force of contraction in LA (n = 5-8, p < 0.05) by 113% ± 24.5% and by 100% ± 38.2% and in HAP (n = 13-15, p < 0.05) by 625% ± 169% and by 196% ± 23.5%, respectively. Carbachol (1 µM) alone exerted a rapid transient maximum negative inotropic effect in LA (n = 6) and HAP (n = 14) to 46.9% ± 3.63% and 19.4% ± 3.74%, respectively (p < 0.05). These negative inotropic effects were smaller in LA (n = 4-6) and HAP (n = 9-12) pretreated with 100 µM cantharidin and amounted to 58.0% ± 2.27% and 59.2% ± 6.19% or 3 mM sodium fluoride to 63.7% ± 9.84% and 46.3% ± 5.69%, (p < 0.05). We suggest that carbachol, at least in part, exerts a negative inotropic effect in the human atrium by stimulating the enzymatic activity of PP1 and/or PP2A.

Cantharidin Topical Solution 0.7%: First Approval.

Cantharidin (YCANTH™) is a proprietary drug-device combination product containing a formulation of cantharidin 0.7% topical solution (a vesicant naturally derived from blister beetles) delivered via a single-use applicator that has been developed by Verrica Pharmaceuticals Inc. for the treatment of molluscum contagiosum and is also being developed for the treatment of warts. In July 2023, YCANTH™ (cantharidin 0.7% topical solution) was approved for the topical treatment of molluscum contagiosum in adult and pediatric patients 2 years of age and older in the USA. This article summarizes the milestones in the development of cantharidin 0.7% topical solution leading to this first approval for the topical treatment of molluscum contagiosum in adult and pediatric patients 2 years of age and older.

YCANTHTM (Cantharidin) Topical Solution.

YCANTHTM (cantharidin) topical solution has been approved recently for the treatment of molluscum contagiosum (MC) in children (aged ≥2 years) and adults. It works by activating serine proteases that lead to blistering and inflammation, promoting shedding of infected cells and viral clearance. In two phase-3, randomized, double-blind, vehicle-controlled trials of similar design, VP-102 (a drug-device combination, containing cantharidin 0.7% w/v and inactive ingredients, such as gentian violet, acetone, and denatonium benzoate, administered with an applicator) was investigated for the treatment of MC. VP-102 and vehicle were applied topically once every 21 days until complete clearance of lesions was observed, or for up to four treatments. Cantharidin demonstrated efficacy in achieving the primary outcome, at day 84/visit 4 (Cantharidin Application in Molluscum Patients [CAMP-1], VP-102: 46% [73/160], vehicle: 18% [19/106]; and CAMP-2, VP-102: 54% [81/150], vehicle: 13% [15/112]). Common adverse events were mild to moderate, such as lesions at the site of application, pruritus, and pain. The recommended regimen of cantharidin topical solution is its application once every 21 days until complete clearance of lesions is observed, or up to four treatments.