Dong-A ST Presents Preclinical Findings Supporting Topical Icotrokinra Development for Psoriasis
Dong-A ST Co., Ltd., a South Korean pharmaceutical company led by President and CEO Jae-hoon Jeong, has presented preclinical research findings demonstrating the potential of a topical formulation of icotrokinra for treating psoriasis. The data were presented at AAPS PharmSci 360 2026, an international pharmaceutical sciences conference held in New Orleans, Louisiana, from October 25 to 28, 2026.
The research highlights the company’s efforts to develop a skin-directed formulation of icotrokinra, a macrocyclic peptide that selectively antagonizes the interleukin-23 (IL-23) receptor. By adapting the molecule for topical administration, Dong-A ST aims to explore a potential treatment approach that delivers the drug directly to affected skin tissues and suppresses inflammatory pathways associated with psoriasis.
The scientific poster, titled “Development of a Topical Icotrokinra Formulation for the Treatment of Psoriasis,” was presented by Hae-sun Kim, Principal Scientist on Dong-A ST’s Drug Delivery System (DDS) team. The study examined the formulation’s ability to penetrate the skin barrier, remain within targeted skin layers, and produce anti-inflammatory effects in preclinical models.
According to the company, an optimized formulation demonstrated favorable skin permeation and retention characteristics in ex vivo assessments. In animal models of induced skin inflammation, topical treatment also attenuated inflammatory responses and significantly reduced the gene expression of interleukin-17A (IL-17A), interleukin-17F (IL-17F), and interleukin-22 (IL-22), cytokines involved in the inflammatory processes associated with psoriasis.
These findings provide early evidence supporting the feasibility of delivering icotrokinra through the skin and its potential to influence localized inflammatory activity. Although further studies are required to establish clinical safety, efficacy, and appropriate dosing, the results support continued investigation of the topical formulation as a potential treatment candidate.
The research also demonstrates how Dong-A ST is applying its proprietary drug delivery capabilities to explore new administration routes for biologic and peptide-based therapeutic approaches. The company has been expanding its DDS platform across multiple dosage forms, including transdermal patches, microneedles, and specialized topical formulations.
AAPS PharmSci 360 Showcases Advances in Pharmaceutical Research
The preclinical findings were presented at AAPS PharmSci 360 2026, organized by the American Association of Pharmaceutical Scientists (AAPS). The annual conference brings together researchers from biotechnology and pharmaceutical companies, academic institutions, regulatory organizations, and drug development teams to discuss advances across pharmaceutical sciences.
The meeting provides a platform for sharing research related to drug discovery, formulation development, drug delivery technologies, manufacturing, and the evaluation of pharmaceutical products.
For companies developing complex molecules, pharmaceutical formulation is an important part of translating a promising active ingredient into a usable treatment. A drug’s therapeutic potential can depend not only on its biological activity but also on how effectively it reaches the intended site of action.
This consideration is particularly relevant to topical therapies, which must overcome the skin’s natural barrier to deliver sufficient quantities of an active ingredient into the appropriate tissue layers.
Dong-A ST’s presentation focused on addressing this challenge for icotrokinra. The research investigated whether a formulation could support dermal delivery while preserving the molecule’s potential to inhibit inflammatory signaling.
The study forms part of the company’s broader efforts to improve drug delivery through formulation technologies designed for different therapeutic needs. By presenting its findings at an international scientific meeting, Dong-A ST highlighted its work at the intersection of peptide pharmacology, topical formulation science, and inflammatory skin disease research.
Icotrokinra Targets the IL-23 Inflammatory Pathway
Icotrokinra is a macrocyclic peptide designed to selectively antagonize the IL-23 receptor. The receptor plays an important role in the signaling processes that contribute to certain immune-mediated inflammatory diseases, including psoriasis.
IL-23 is a cytokine involved in regulating immune responses and maintaining inflammatory activity. Its signaling can contribute to the activation and persistence of immune pathways associated with psoriasis, a chronic inflammatory skin condition characterized by red, scaly, and often itchy plaques.
The IL-23 pathway is an established target in psoriasis treatment. By interfering with this signaling system, therapeutic agents can help reduce inflammatory activity that contributes to the disease.
Icotrokinra’s mechanism involves selective antagonism of the IL-23 receptor, thereby inhibiting IL-23-mediated pro-inflammatory signaling. Its macrocyclic peptide structure is designed to interact with the receptor and block the pathway responsible for driving relevant immune responses.
An oral therapy containing icotrokinra as its active ingredient received approval from the U.S. Food and Drug Administration (FDA) in March 2026, according to the company announcement. The oral product provides a foundation for investigating the molecule’s potential across different delivery approaches.
Dong-A ST’s research examines whether icotrokinra can also be formulated for topical administration. This represents a distinct development strategy because a formulation intended for application to the skin must overcome delivery challenges that do not apply in the same way to an oral product.
A topical formulation would need to release the active ingredient from its vehicle, enable it to cross the skin barrier, and retain sufficient amounts in the relevant tissue to produce the intended pharmacological effect.
The company is therefore investigating both the physical delivery characteristics of the formulation and its ability to influence inflammatory markers in preclinical models.
Importantly, the existing approval of an oral icotrokinra product does not establish the safety or effectiveness of a topical formulation. A new administration route can alter drug exposure, distribution, tolerability, and other characteristics, making formulation-specific testing and clinical evaluation necessary.
Optimizing Skin Penetration and Drug Retention
One of the central objectives of Dong-A ST’s study was to determine whether icotrokinra could be delivered effectively through the skin and retained within the targeted tissue layers.
The outermost layer of the skin, the stratum corneum, serves as a protective barrier that limits the entry of external substances. While this function is essential for maintaining skin integrity, it can also make topical drug delivery challenging, particularly for molecules that require specialized formulation approaches.
A topical formulation must balance several factors, including the ability of the active ingredient to move through the skin, its retention at the intended site, and the characteristics of the formulation itself.
In its study, Dong-A ST evaluated the skin permeation and retention profiles of different formulation approaches using ex vivo assessments. These experiments allow researchers to examine how a compound moves through skin tissue outside a living organism.
The assessment identified an optimized formulation capable of penetrating the skin and retaining icotrokinra within the targeted skin layers, according to the company.
This finding is important because effective topical treatment does not necessarily require the active ingredient to reach high concentrations throughout the body. Depending on the drug’s mechanism and intended application, localized delivery may offer a way to concentrate activity in affected tissue.
For a potential psoriasis treatment, retaining the active ingredient in the skin could support efforts to influence local inflammatory processes. However, the extent to which this approach translates into therapeutic benefit will depend on additional factors, including the concentration achieved in relevant tissues, the duration of exposure, and the formulation’s tolerability.
The reported results represent an early formulation milestone rather than evidence of clinical efficacy. Further research will be needed to characterize the delivery profile in greater detail and determine whether the optimized formulation can provide suitable exposure under conditions relevant to human treatment.
Preclinical Models Show Reductions in Inflammatory Cytokine Expression
In addition to assessing skin delivery, Dong-A ST investigated the biological effects of topical icotrokinra in animal models of induced skin inflammation.
The company reported that treatment attenuated inflammatory responses and significantly reduced the gene expression of three cytokines associated with psoriasis: IL-17A, IL-17F, and IL-22.
These cytokines are involved in inflammatory signaling and interactions between immune cells and skin cells. Their activity can contribute to the changes in skin function and appearance associated with psoriasis.
IL-17A is a key mediator of inflammation in several immune-related conditions. In psoriasis, IL-17A signaling can promote inflammatory responses in keratinocytes, the predominant cells in the outer layers of the skin.
IL-17F is related to IL-17A and can also contribute to inflammatory activity. Both cytokines are involved in pathways that influence the production of inflammatory mediators and the recruitment of immune cells.
IL-22 also participates in immune signaling and can affect the behavior of skin cells. In psoriasis, its activity has been associated with changes in epidermal function and the abnormal thickening of affected skin.
The reduction in gene expression of these three cytokines suggests that topical icotrokinra influenced inflammatory pathways in the animal models used in the study.
These findings are relevant to the candidate’s proposed mechanism because IL-23 signaling is connected to downstream immune processes that involve IL-17-related pathways and other inflammatory mediators.
Nevertheless, changes in cytokine gene expression are preclinical biological findings and do not automatically predict clinical improvement. Additional studies must determine whether the observed effects correspond to improvements in disease severity, skin symptoms, and other outcomes relevant to patients.
The research also does not establish how the formulation would perform across different forms or severities of psoriasis, or whether it would provide advantages over existing topical treatments.
Even so, the combination of favorable skin delivery characteristics and reductions in inflammatory markers supports further investigation of the formulation.
Potential Role in Topical Psoriasis Treatment
Psoriasis treatment options include topical medications, phototherapy, oral systemic therapies, and injectable biologic medicines. The choice of treatment can depend on disease severity, the areas of the body affected, previous treatment responses, patient preferences, and other clinical considerations.
Topical treatments are frequently used for localized disease and can be important components of treatment plans for patients who do not require systemic therapy or who need additional management of particular skin areas.
However, topical treatment can present challenges, including the need for regular application, differences in skin penetration, local tolerability, and the suitability of particular formulations for different body sites.
Dong-A ST’s research explores whether icotrokinra could provide another approach by combining a target-specific mechanism with direct application to affected skin.
A successful topical formulation could potentially offer a localized way to inhibit IL-23-mediated inflammatory signaling. Whether this would translate into meaningful clinical benefits remains to be established through further development.
The company has not reported clinical trial results for the topical candidate in the supplied announcement. Consequently, its safety, tolerability, dosing requirements, effectiveness, and potential place in psoriasis treatment remain undetermined.
Future development would need to establish whether the formulation can achieve consistent skin exposure, maintain its physical and chemical stability, and provide an appropriate balance between local activity and systemic exposure.
Clinical studies would also need to assess outcomes such as changes in disease severity, treatment tolerability, and the duration of any observed response.
Dong-A ST Builds on Its Drug Delivery System Platform
The topical icotrokinra program forms part of Dong-A ST’s broader efforts to strengthen its proprietary Drug Delivery System platform.
Over the past decade, the company has worked on delivery technologies spanning transdermal patches, microneedles, and specialized topical formulations. These approaches address different challenges associated with administering active pharmaceutical ingredients and delivering them to intended sites of action.
Transdermal patches are designed to deliver drugs through the skin, while microneedle technologies use small projections to facilitate delivery across the skin barrier. Specialized topical formulations, meanwhile, can be developed to support the local application and distribution of active ingredients.
Each delivery approach has different formulation, manufacturing, and performance requirements. The appropriate technology depends on the properties of the active ingredient, the desired site of action, the required exposure, and the intended therapeutic use.
Dong-A ST plans to continue developing drug delivery approaches for a broad range of therapeutic applications, building on its existing technical capabilities.
The icotrokinra study illustrates how the company’s DDS expertise can be applied to investigate alternative formulations of a molecule with an established mechanism targeting inflammatory disease pathways.
By evaluating both dermal delivery and biological activity, the company is seeking to establish whether the molecule can be adapted to a different administration route while retaining its potential therapeutic relevance.
Market Interest in Inflammatory Skin Disease Treatments
The development of new psoriasis therapies takes place in a market where treatment approaches continue to diversify, including the use of targeted biologics and non-steroidal topical medications.
According to the company announcement, Bank of America projections estimate that oral icotrokinra could achieve peak annual sales of $4.5 billion. This figure is a forecast for the oral therapy and should not be interpreted as a sales projection for Dong-A ST’s investigational topical formulation.
The announcement also cited commercial performance in the topical inflammatory skin disease market. Incyte’s topical Janus kinase (JAK) inhibitor Opzelura® generated approximately $678 million in sales in 2025, while Organon’s Vtama® recorded $128 million during the same year.
These products illustrate commercial activity in the topical treatment segment, although their mechanisms and approved uses differ from the proposed topical icotrokinra approach. Their sales figures do not establish the potential market share or commercial prospects of Dong-A ST’s candidate.
For developers of new topical therapies, commercial opportunities can depend on clinical differentiation, safety, efficacy, ease of use, treatment duration, pricing, reimbursement, and competition from established medicines.
Any future commercial potential for topical icotrokinra would therefore depend on successful development and regulatory authorization, as well as evidence demonstrating its value relative to available treatment options.
Further Studies Needed to Establish Clinical Potential
Dong-A ST’s presentation at AAPS PharmSci 360 2026 marks a research milestone in the investigation of topical icotrokinra for psoriasis. The reported results suggest that the company has identified a formulation with favorable skin permeation and retention characteristics and demonstrated anti-inflammatory activity in preclinical animal models.
The reductions in IL-17A, IL-17F, and IL-22 gene expression provide additional evidence that the formulation may influence inflammatory processes relevant to psoriasis.
However, these findings remain preliminary. Further research will be necessary to establish the candidate’s clinical safety, effectiveness, appropriate dosing, and suitability for patients with psoriasis.
Additional formulation development and testing may also be required to establish product stability, reproducibility, and consistent delivery under intended conditions of use.
For Dong-A ST, the program represents an opportunity to apply its DDS platform to a targeted peptide-based approach for inflammatory skin disease. As development continues, future studies will determine whether the formulation can progress from preclinical promise to a clinically useful topical treatment.
The company’s broader strategy of advancing transdermal, microneedle, and topical delivery technologies reflects its continued focus on developing formulation solutions for diverse therapeutic applications. The icotrokinra research adds to these efforts by examining how a molecule targeting the IL-23 receptor might be adapted for localized delivery.
Ultimately, the next stages of development will need to demonstrate whether the preclinical findings translate into meaningful benefits for patients. Until clinical evidence becomes available and the necessary regulatory requirements are met, topical icotrokinra remains an investigational candidate rather than an established treatment for psoriasis.