Periodic Reporting for period 2 - PROTO (PROTO - Advanced PeRsOnalized Therapies for Osteoarthritis – TACKLING INFLAMMATION TO IMPROVE PATIENT OUTCOMES)
Reporting period: 2024-07-01 to 2025-12-31
Osteoarthritis (OA) is a chronic progressive joint disorder, characterized by inflammation causing pain, stiffness, swelling and gradual loss of joint function.
OA affects over 16% of the global adult population, and it is the most common and rapidly growing form of arthritis, leading to reduced mobility and chronic disability and is associated with cardiovascular and metabolic co-morbidities. OA is mostly triggered by micro- and macro-injuries to affected joints, where repair processes initiate proinflammatory immune cascades that eventually lead to progressive joint destruction. This vicious cycle results in cartilage degradation, subchondral bone remodelling and low-grade joint inflammation. To date there are no disease modifying treatments that can prevent or slow down OA.
Within PROTO we have joined forces to address the key feature of OA progression – inflammation.
We intend to do this in a two-pronged approach addressing different early inflammatory disease stages.
(i) We will use an innovative anti-inflammatory allogeneic placental (PLX-PAD) cell therapy to treat patients with early-stage knee OA as a direct approach to reduce inflammation and degeneration.
(ii) We will train patients following anterior cruciate ligament reconstruction (ACLR) a few months after surgery, to restore normal biomechanics and alleviate mechanically induced inflammation within the joint. This group will serve as a pre-stage knee OA group, as in previous work we have shown that pathological gait patterns in persons after ACLR or with knee OA are associated with progressive cartilage loss and persistent inflammation.
OA affects over 16% of the global adult population, and it is the most common and rapidly growing form of arthritis, leading to reduced mobility and chronic disability and is associated with cardiovascular and metabolic co-morbidities. OA is mostly triggered by micro- and macro-injuries to affected joints, where repair processes initiate proinflammatory immune cascades that eventually lead to progressive joint destruction. This vicious cycle results in cartilage degradation, subchondral bone remodelling and low-grade joint inflammation. To date there are no disease modifying treatments that can prevent or slow down OA.
Within PROTO we have joined forces to address the key feature of OA progression – inflammation.
We intend to do this in a two-pronged approach addressing different early inflammatory disease stages.
(i) We will use an innovative anti-inflammatory allogeneic placental (PLX-PAD) cell therapy to treat patients with early-stage knee OA as a direct approach to reduce inflammation and degeneration.
(ii) We will train patients following anterior cruciate ligament reconstruction (ACLR) a few months after surgery, to restore normal biomechanics and alleviate mechanically induced inflammation within the joint. This group will serve as a pre-stage knee OA group, as in previous work we have shown that pathological gait patterns in persons after ACLR or with knee OA are associated with progressive cartilage loss and persistent inflammation.
During the second period, the project advanced steadily across all work packages, ensuring coordinated progress and preparing the ground for upcoming clinical and translational milestones. WP1 maintained effective project management through continuous monitoring of progress and risks, timely distribution of interim payments, preparation of expert reviews, and organization of consortium and review meetings, culminating in the completion of the second periodic report.
In WP2, we successfully characterized and released clinical batches of PLX PAD cells for the study. Transcriptome and cytokine secretion analyses across four batches from two donors—under baseline and IFN γ–stimulated conditions—confirmed a distinct expression profile compared with bone marrow and adipose derived MSCs, as well as strong batch to batch reproducibility, reinforcing the robustness of the PLX PAD product.
WP3 achieved a major regulatory milestone with approval to initiate a Phase I study. Patient screening began in Q4 2025, with first treatment planned for Q1 2026. The preclinical manuscript on safety and efficacy of intra articular PLX PAD administration was finalized and is scheduled for submission in Q1 2026.
WP4 transitioned from methodological development to clinical implementation. The validated gait score and personalized digital training program were integrated into the ongoing study. Recruitment and biomechanical screening expanded, supported by an approved ethics amendment enabling additional sites, optimized recruitment workflows, digital adherence monitoring, and verification of biomechanical and MRI data quality.
In WP5, immunological and molecular profiling workflows established in RP1 were applied at scale. Deep immunophenotyping of synovial fluid and blood demonstrated reproducibility in challenging matrices. The clinical reference framework was expanded through analyses of ACL injury patients, and immune profiling of WP4 samples began. Molecular profiling for tissue turnover biomarkers in synovial fluid was extended using late stage OA samples. Sample collection and cryopreservation for cytokine, tissue turnover, and genetic analyses were initiated across WP3 and WP4.
WP6 completed two major achievements: improved deep learning software for automated detection of Hoffa synovitis with clinical validation, and development of a second deep learning tool for automated effusion synovitis analysis, successfully applied to a large cohort.
In WP7, advanced in vitro models revealed that inflammatory signals impair chondrocyte phenotype and function, while PLX PAD exerts immunomodulatory and regenerative effects. Identification of key signalling pathways and development of refined organoid and microfluidic systems strengthened the mechanistic understanding of OA and therapeutic potential.
Finally, WP8 ensured strong dissemination and communication: 62 conference presentations and 22 peer reviewed publications increased scientific visibility, while the LinkedIn page and an expanded patient focused website section enhanced outreach and stakeholder engagement.
In WP2, we successfully characterized and released clinical batches of PLX PAD cells for the study. Transcriptome and cytokine secretion analyses across four batches from two donors—under baseline and IFN γ–stimulated conditions—confirmed a distinct expression profile compared with bone marrow and adipose derived MSCs, as well as strong batch to batch reproducibility, reinforcing the robustness of the PLX PAD product.
WP3 achieved a major regulatory milestone with approval to initiate a Phase I study. Patient screening began in Q4 2025, with first treatment planned for Q1 2026. The preclinical manuscript on safety and efficacy of intra articular PLX PAD administration was finalized and is scheduled for submission in Q1 2026.
WP4 transitioned from methodological development to clinical implementation. The validated gait score and personalized digital training program were integrated into the ongoing study. Recruitment and biomechanical screening expanded, supported by an approved ethics amendment enabling additional sites, optimized recruitment workflows, digital adherence monitoring, and verification of biomechanical and MRI data quality.
In WP5, immunological and molecular profiling workflows established in RP1 were applied at scale. Deep immunophenotyping of synovial fluid and blood demonstrated reproducibility in challenging matrices. The clinical reference framework was expanded through analyses of ACL injury patients, and immune profiling of WP4 samples began. Molecular profiling for tissue turnover biomarkers in synovial fluid was extended using late stage OA samples. Sample collection and cryopreservation for cytokine, tissue turnover, and genetic analyses were initiated across WP3 and WP4.
WP6 completed two major achievements: improved deep learning software for automated detection of Hoffa synovitis with clinical validation, and development of a second deep learning tool for automated effusion synovitis analysis, successfully applied to a large cohort.
In WP7, advanced in vitro models revealed that inflammatory signals impair chondrocyte phenotype and function, while PLX PAD exerts immunomodulatory and regenerative effects. Identification of key signalling pathways and development of refined organoid and microfluidic systems strengthened the mechanistic understanding of OA and therapeutic potential.
Finally, WP8 ensured strong dissemination and communication: 62 conference presentations and 22 peer reviewed publications increased scientific visibility, while the LinkedIn page and an expanded patient focused website section enhanced outreach and stakeholder engagement.
The ambitious programme of PROTO aims to halt and partially reverse the structural and functional changes caused by inflammatory processes in OA.
Our ambitious goal is to introduce: (i) the highly innovative anti-inflammatory local placental derived cell therapy in early-stage OA patients and (ii) a personalized sensor-based training intervention intended to prevent inflammation and OA onset during a crucially important ‘window of opportunity’ by correcting pathological movement patterns in pre-stage OA patients. A vast array of mechanistic side studies are conducted within PROTO and have already revealed important mechanisms, which support the clinical anti-inflammatory treatment approach.
Our ambitious goal is to introduce: (i) the highly innovative anti-inflammatory local placental derived cell therapy in early-stage OA patients and (ii) a personalized sensor-based training intervention intended to prevent inflammation and OA onset during a crucially important ‘window of opportunity’ by correcting pathological movement patterns in pre-stage OA patients. A vast array of mechanistic side studies are conducted within PROTO and have already revealed important mechanisms, which support the clinical anti-inflammatory treatment approach.