Plexis Long-acting Injectable

Sponsor(s)

No sponsor indicated

Partnerships

Eupraxia Pharmaceuticals https://eupraxiapharma.com/

Type of technology

Polymer-based particles

Administration route

Subcutaneous, Intra-articular, Intra-vitreal, Intra-esophegal

Development state and regulatory approval

fluticasone

Phase II

Not provided

Description

Plexis is a proprietary long-acting injectable drug delivery technology that uses high-drug-loading microparticles and diffusion-controlled release to achieve smooth, predictable pharmacokinetics, enabling convenient monthly subcutaneous dosing with scalable manufacturing and room-temperature stability.

Technology highlight

Plexis is a proprietary long-acting injectable drug delivery platform that enables predictable, diffusion-controlled release from high–drug-loading microparticles, supporting convenient monthly subcutaneous dosing; the technology has demonstrated clinical proof of concept in Phase I and Phase IIb studies and is being applied across CNS, inflammatory, transplant, and antiviral indications to improve adherence and long-term outcomes in chronic diseases.

Technology main components

Plexis consists of high–drug-loading (>90%) active pharmaceutical ingredient (API) microparticles coated with a thin, biocompatible polymer membrane that governs diffusion-controlled release. The system includes (i) size-controlled drug cores, (ii) a laminated polymer coating that enables tunable release kinetics, and (iii) an aqueous suspension vehicle optimized for syringeability and subcutaneous injection. Release rate is adjusted by particle size distribution and membrane properties rather than polymer degradation.

Information on the raw materials sourcing, availability and anticipated price

Raw materials include the API, pharmacopeia-grade polymer excipients (e.g., USP/NF polymers), standard crosslinking agents, and aqueous suspension excipients. All materials are commercially available from multiple qualified suppliers with established GMP supply chains. No rare or constrained materials are required. Costs are comparable to conventional injectable excipients; the primary cost driver remains the API. The platform is compatible with scalable, cost-effective manufacturing and is not dependent on cold-chain–specific materials.

Delivery device(s)

No delivery device

API desired features

Water-insoluble molecules

Min: 1 Max: 100 Unit: µg/mL
Plexis is optimized for APIs with low aqueous solubility (µg/mL to low mg/mL range at physiological pH). Sustained release is governed primarily by particle size and membrane properties rather than API dissolution rate, enabling predictable long-acting delivery of poorly soluble small molecules.

Small molecules

Plexis is designed for small-molecule APIs across a broad range of chemotypes, particularly lipophilic or poorly water-soluble compounds. Representative applications include CNS agents (e.g., antipsychotics), anti-inflammatory drugs, immunosuppressants, and antivirals. The platform supports high drug loading (>90 wt%), tunable release kinetics, and monthly subcutaneous administration.

Additional solubility data

Plexis is best suited to small-molecule APIs with low-to-moderate aqueous solubility (typical range: µg/mL to low mg/mL at physiological pH). Drug release is governed primarily by particle size and membrane properties rather than requiring high API solubility. Where needed, standard solid-state optimization (salt/cocrystal selection, polymorph control) can be used to tune apparent solubility and release.

Additional stability data

Plexis formulations are designed for robust physical and chemical stability, with room-temperature storage as a key design objective. Because release is diffusion-controlled and not dependent on polymer degradation, performance is less sensitive to hydrolytic aging than many PLGA depots. Stability is supported through routine ICH-condition testing (appearance, assay, impurities, particle size, and in vitro release) and can be tailored to target shelf-life requirements.

API loading: Maximum drug quantity to be loaded

> 90% wt%

API co-administration

2 different APIs : Co-administration of up to two APIs is feasible using separate, independently formulated microparticle populations suspended in a common injection vehicle. APIs should be small molecules with compatible physicochemical properties (e.g., low aqueous solubility, LogP ~1.5–6.5) and chemical stability under formulation conditions. Total injected dose must remain within clinically acceptable volume and tolerability limits. Compatibility, release kinetics, and local tolerability are evaluated case-by-case.

LogP

Not provided
Plexis has been successfully applied to moderately to highly lipophilic small molecules; diffusion-controlled release is well suited to APIs with limited aqueous solubility but does not strictly exclu

Scale-up prospects

Plexis is well suited for scale-up using standard pharmaceutical unit operations. The manufacturing process relies on controllable particle sizing and membrane coating steps that are scalable by increasing batch size or equipment capacity rather than altering formulation fundamentals. The platform has been successfully produced at laboratory and pilot scales, with a clear path to GMP clinical and commercial manufacturing.

Tentative equipment list for manufacturing

Key equipment includes particle size reduction and classification tools (mills, sieves), fluidized-bed or spray-based coating systems, standard mixing vessels for suspension preparation, filtration and drying equipment, and conventional sterile fill–finish systems. No highly specialized or custom-built equipment is required, enabling technology transfer to multiple CMOs.

Manufacturing

Manufacturing can be performed in standard GMP pharmaceutical facilities with controlled environments appropriate for sterile injectable products. No extreme temperature, pressure, or environmental conditions are required. The process is compatible with common solvent handling and recovery practices, standard cleaning validation, and established quality systems for parenteral drug products.

Specific analytical instrument required for characterization of formulation

Formulation characterization relies on standard analytical tools, including HPLC/UPLC for assay and impurities, particle size analysis (e.g., laser diffraction), microscopy/SEM for morphology, in vitro release testing apparatus, and routine physicochemical tests (pH, viscosity). No bespoke analytical platforms are required beyond those commonly available in pharmaceutical QC laboratories.

STEPUP

Identifier

NCT02609126

Link

https://clinicaltrials.gov/study/NCT02609126

Phase

Phase I

Status

Completed

Sponsor

Eupraxia Pharmaceuticals Inc.

More details

The main purpose of this study is to understand the pharmacokinetics of EP-104IAR and to determine whether it is safe to use in patients with osteoarthritis (OA) of the knee. The study will also provide some preliminary insights into whether the experimental treatment reduces pain in the knee. Osteoarthritis is the most common joint disease, affecting over 20 million people in the US alone. Currently, pain treatments that are injected directly into the knee often work for only a short time and may also have side effects within the rest of the body. The experimental treatment is a steroid that is in the same family of drugs as the most common current injectable treatments for knee osteoarthritis. For this study, the drug is coated with a polymer intended to prolong the time it stays inside

Purpose

Safety Study of a Long-Acting Injectable Steroid to Treat Knee Osteoarthritis

Interventions

Intervention 1

Intervention 2

Countries

Sites / Institutions

Not provided

Trials dates

Anticipated Start Date
Not provided

Actual Start Date
2016-04-01

Anticipated Date of Last Follow-up
2021-08-30

Estimated Primary Completion Date
Not provided

Estimated Completion Date
Not provided

Actual Primary Completion Date
2017-12-28

Actual Completion Date
2017-12-28

Studied populations

Age Cohort

• Adults
• Older Adults

Genders

• All

Accepts pregnant individuals
Unspecified

Accepts lactating individuals
Unspecified

Accepts healthy individuals
No

Comments about the studied populations

Inclusion Criteria: * OA of Index Knee * Kellgren Lawrence Grade 2 or 3 * Patient-reported pain (PtPain) of Index Knee ≥4 but ≤9 * PtPain of non-Index Knee \<6 * BMI ≦ 40 kg/m2 Exclusion Criteria: * Intra-articular joint injection in the Index Knee within the past 8 weeks for glucocorticoids and 6 months for hyaluronic acid * Insulin-dependent diabetes * Active infection * Pregnant or breast feeding

Health status

Not provided

Study type

Interventional (clinical trial)

Enrollment

32

Allocation

Randomized

Intervention model

Parallel Assignment

Intervention model description

Not provided

Masking

Double-blind masking

Masking description

Not provided

Frequency of administration

Studied LA-formulation(s)

Studied route(s) of administration

Use case

Treatment

Key resources

SPRINGBOARD

Identifier

NCT04120402

Link

https://clinicaltrials.gov/study/NCT04120402

Phase

Phase II

Status

Completed

Sponsor

Eupraxia Pharmaceuticals Inc.

More details

The purpose of this study is to evaluate the safety, efficacy and pharmacokinetics (PK) of EP-104IAR in patients with osteoarthritis (OA) of the knee

Purpose

Study to Evaluate the Efficacy and Safety of EP-104IAR in Patients With Osteoarthritis of the Knee

Interventions

Intervention 1

Intervention 2

Countries

Sites / Institutions

Not provided

Trials dates

Anticipated Start Date
Not provided

Actual Start Date
2021-09-10

Anticipated Date of Last Follow-up
2024-05-29

Estimated Primary Completion Date
Not provided

Estimated Completion Date
Not provided

Actual Primary Completion Date
2023-05-17

Actual Completion Date
2023-06-01

Studied populations

Age Cohort

• Adults
• Older Adults

Genders

• All

Accepts pregnant individuals
Unspecified

Accepts lactating individuals
Unspecified

Accepts healthy individuals
No

Comments about the studied populations

Key Inclusion Criteria: * Males or females, aged ≥40 years * Body Mass Index (BMI) ≤ 40.0 kg/m2 * Diagnosis of primary OA of the Index knee, with symptoms present for at least 6 months * OA severity Grade 2 or 3 (based on Kellgren Lawrence Grading Scale) * Unsatisfactory pain relief from at least 2 prior standard OA treatments * Qualifying pain in the Index knee during the baseline period * Ambulatory (without the need for a cane/other walking aide) * Female subjects willing to use highly effective birth control methods to prevent pregnancy * Willing and able to comply with study procedures and restrictions, including abstaining from use of restricted medications. Key Exclusion Criteria: * OA of the Index knee due to acute injury or trauma, or unstable joint

Health status

Not provided

Study type

Interventional (clinical trial)

Enrollment

318

Allocation

Randomized

Intervention model

Parallel Assignment

Intervention model description

Not provided

Masking

Quadruple-blind masking

Masking description

Not provided

Frequency of administration

Studied LA-formulation(s)

Studied route(s) of administration

Use case

Treatment

Key resources

RESOLVE

Identifier

NCT05608681

Link

https://clinicaltrials.gov/study/NCT05608681

Phase

Phase I/II

Status

Recruiting

Sponsor

Eupraxia Pharmaceuticals Inc.

More details

A Phase 1b/2 study to explore the safety, efficacy and pharmacokinetics of EP-104GI in adults with eosinophilic esophagitis (EoE). Endoscopic and histologic assessments will also be evaluated to understand the local effects of EP-104GI on eosinophilic EoE disease activity. Approximately 27 to 33 participants will be enrolled in dose escalation: 3-6 participants per dose cohort. The number of participants enrolled in escalation will depend on the number of dose escalation cohorts evaluated, and dose cohorts needing to be expanded. An additional 10-24 participants will be enrolled in 1 or 2 cohorts of 10-12 participants each at tolerable dose regimen(s) selected based on the accumulated clinical data to identify the recommended phase 2 dose(s) (RP2D). In the Phase 2 randomized dose optimizat

Purpose

A Trial to Evaluate EP-104GI in Adults With Eosinophilic Esophagitis (EoE).

Interventions

Intervention 1

Intervention 2

Countries

Sites / Institutions

Not provided

Trials dates

Anticipated Start Date
Not provided

Actual Start Date
2023-03-31

Anticipated Date of Last Follow-up
2026-03-17

Estimated Primary Completion Date
2026-12-01

Estimated Completion Date
2026-12-01

Actual Primary Completion Date
Not provided

Actual Completion Date
Not provided

Studied populations

Age Cohort

• Adults
• Older Adults

Genders

• All

Accepts pregnant individuals
Unspecified

Accepts lactating individuals
Unspecified

Accepts healthy individuals
No

Comments about the studied populations

Inclusion Criteria: * Symptomatic EoE; * For women of childbearing potential, a negative pregnancy test and willing to use a highly effective method of birth control until end of study; * Willing and able to adhere to study-related procedures and visit schedule; * Willing and able to provide informed consent. Criteria for crossover to EP 104GI from vehicle control (randomized dose optimization portion): 1. Has completed the randomized dose optimization portion of the trial to Week 24, inclusive 2. Without safety concerns for receiving EP 104GI ie, does not meet exclusion criteria or have other safety issue Exclusion Criteria: * Concomitant esophageal disease, relevant GI disease, or any condition, history, or laboratory abnormality that might interfere with the study; * Oral or esopha

Health status

Not provided

Study type

Interventional (clinical trial)

Enrollment

117

Allocation

Randomized

Intervention model

Cross-over assignment

Intervention model description

Not provided

Masking

Quadruple-blind masking

Masking description

Not provided

Frequency of administration

Studied LA-formulation(s)

Studied route(s) of administration

Use case

Treatment

Key resources

LAI-tacrolimus Phase 1 Study

Identifier

NCT03626714

Link

https://clinicaltrials.gov/study/NCT03626714

Phase

Phase I

Status

Completed

Sponsor

Auritec Pharmaceuticals

More details

First-in-human study assessing systemic exposure and safety of a sustained-release tacrolimus formulation following subcutaneous administration.

Purpose

To evaluate the safety, tolerability, and pharmacokinetics of a long-acting injectable tacrolimus formulation in healthy volunteers.

Interventions

Not provided

Countries

Sites / Institutions

Not provided

Trials dates

Anticipated Start Date
Not provided

Actual Start Date
Not provided

Anticipated Date of Last Follow-up
Not provided

Estimated Primary Completion Date
Not provided

Estimated Completion Date
Not provided

Actual Primary Completion Date
Not provided

Actual Completion Date
Not provided

Studied populations

Age Cohort
Unspecified

Genders
Unspecified

Accepts pregnant individuals
Unspecified

Accepts lactating individuals
Unspecified

Accepts healthy individuals
Unspecified

Comments about the studied populations

Not provided

Health status

Not provided

Study type

Not provided

Enrollment

Not provided

Allocation

Not provided

Intervention model

Not provided

Intervention model description

Not provided

Masking

Not provided

Masking description

Not provided

Frequency of administration

Not provided

Studied LA-formulation(s)

Not provided

Studied route(s) of administration

Not provided

Use case

Not provided

Key resources

Proprietary excipients used

No proprietary excipient used

Novel excipients or existing excipients at a concentration above Inactive Ingredients Database (IID) for the specified route of administration

No novel excipient or existing excipient used

Residual solvents used

Organic solvents may be used transiently during manufacturing (e.g., during coating or processing steps), but they are removed during downstream processing. Residual solvent levels in the final drug product are controlled and tested to meet ICH Q3C limits and applicable regulatory requirements.

Other features of the technology

• Biodegradable
• Drug-eluting
• Room temperature storage
• At least 1 year shelf life

Release properties

Plexis provides sustained, diffusion-controlled drug release via high–drug-loading (>90%) microparticles coated with a thin, biocompatible polymer membrane. Release kinetics are smooth and predictable, with reduced burst and variability compared to degradation-based depots, and can be tuned by particle size and membrane properties to support monthly or longer dosing intervals.

Injectability

Plexis formulations are designed for subcutaneous administration using small-gauge needles and clinically practical injection volumes. High drug loading enables lower injection volumes relative to conventional polymer depots, supporting improved syringeability, patient comfort, and use in outpatient and chronic care settings.

Stability

Plexis formulations demonstrate robust physical and chemical stability, supported by ongoing and completed stability studies. The diffusion-based release mechanism is not dependent on polymer degradation, contributing to consistent performance over time and enabling extended shelf life under controlled room-temperature conditions.

Storage conditions and cold-chain related features

Plexis drug products are designed for room-temperature stability, eliminating the need for cold-chain storage. This simplifies distribution, reduces logistical complexity and cost, and improves accessibility in outpatient, community, and resource-limited healthcare settings.

Safety

The Plexis platform uses biocompatible materials with prior regulatory acceptance. Safety and local tolerability have been demonstrated in preclinical studies and in Phase I and Phase IIb clinical trials across multiple molecules, with favorable injection-site histopathology and no unexpected safety signals attributable to the delivery system.

Efficacy

Not provided

Evidence Summary

Not provided

Therapeutic area(s)

Use case(s)

Use of technology

Description

Sustained-release injectable formulations and methods of delivering fluticasone using high–drug-loading crystalline microparticles with controlled release properties.

Brief description

The patent claims sustained-release corticosteroid formulations based on coated microparticles designed for diffusion-controlled release. It includes APIs, polymer membranes, and methods for achieving prolonged therapeutic exposure and improved local efficacy. This IP is relevant to long-acting injectable applications, including site-specific therapeutic delivery. The claims include compositions and methods for extended local therapeutic exposure following a single administration and aspects of particle formulation and membrane selection.

Representative patent

WO2014153541

Category

Formulation

Patent holder

Eupraxia Pharmaceuticals Inc.

Exclusivity

Exclusive (owned by Eupraxia Pharmaceuticals; no public non-exclusive license reported)

Expiration date

March 21, 2034

Status

Granted: AU, CN, HK, IN, IL, JP, KR, NZ, SG, TW, GB, US, MX, EP (AL, BE, CH, CY, DE, DK, EE, FI, FR, GB, GR, HR, HU, IE, IS, IT, LI, LV, MC, MT, NL, NO, RO, SE, SI, SM, BA, ME) Not in force: BG, CL, RU, AT, CZ, ES, LT, LU, PL, PT, RS, SK, TR, MK

Description

Polymer-coated microparticle drug delivery systems designed to provide sustained, diffusion-controlled release of active pharmaceutical ingredients.

Brief description

The disclosed technology enables extended local or systemic drug exposure using high drug loading, tunable membrane properties, and controlled particle size, supporting long-acting injectable and implantable therapeutic applications. Claims relate to compositions and methods for delivering drugs using polymer-coated microparticles that regulate release via diffusion across a biocompatible membrane rather than polymer degradation. The invention covers particle architecture, coating materials, and methods for achieving sustained, predictable drug release suitable for long-acting therapies.

Representative patent

WO2004058223

Category

Drug delivery system

Patent holder

Auritec Pharmaceuticals, Inc.

Exclusivity

Exclusive (owned by Auritec Pharmaceuticals)

Expiration date

December 22, 2023

Status

Expired: AU, CA, JP Term extended: US9492388 (until 26.12.2029)

Publications

There are no publication

Additional documents

No documents were uploaded

Useful links

• 2018- Auritec Pharmaceuticals Completes Enrollment for its Sustained-release Depot Tacrolimus Clinical Trial

• Auritec Pharma on SBIR.gov (America's seed fund)

• Auritec Pharma on PatSnap's Synapse

• Patented Technologies In Ocular Drug Delivery System: An Overview - includes Plexis (r) platform technology