Enlivex Reports 79.2% Allocetra Response in Older Knee OA Patients

Enlivex reported favorable 12-month topline results from the randomized, double-blind, placebo-controlled Phase IIa stage of its multinational Phase I/IIa trial (ENX-CL-05-001), evaluating Allocetra™ in patients with moderate-to-severe knee osteoarthritis (KOA). Among patients aged 64 years and older, 79.2% of those receiving Allocetra achieved a clinically meaningful response at 12 months, compared with 47.6% in the placebo group (p=0.027).

The results indicate that the clinical benefit observed after treatment was maintained through one year following a single treatment cycle comprising three intra-articular injections. The findings are particularly relevant to the company’s ongoing Phase IIb programme, which is evaluating Allocetra in the same age-defined patient population.

Responder Rates Favor Allocetra Through 12 Months

The 12-month responder analysis showed a 31.6 percentage-point difference between Allocetra and placebo, representing a 66% higher relative responder rate in the treatment group. The response was based on clinically meaningful improvements in pain and knee function.

The treatment advantage was also evident at earlier assessments. Allocetra demonstrated an 80% higher responder rate than placebo at three months (p=0.019) and a 39% higher rate at six months (p=0.168). Although the six-month comparison did not reach statistical significance, the 12-month result achieved statistical significance.

Patient-reported outcomes further supported the treatment effect. On the 0–100 WOMAC scale, where lower scores indicate improvement, the difference between Allocetra and placebo in change from baseline was:

• WOMAC pain: 17.5 points at three months (p=0.004), 15.4 points at six months (p=0.012) and 12.2 points at 12 months (p=0.113).
• WOMAC physical function: 19.3 points at three months (p=0.0008), 19.5 points at six months (p=0.0008) and 13.1 points at 12 months (p=0.067).

Although both measures continued to favor Allocetra at 12 months, neither comparison reached statistical significance at that assessment. The findings therefore suggest persistence of the treatment advantage, while the strongest statistically significant differences in pain and function occurred during the first six months.

Age-Related Response and Safety Findings

Enlivex identified patient age as the strongest predictor of treatment response, with greater treatment effects observed among older participants. Improvements in patient-reported outcomes were also supported by physical performance assessments and exploratory serum biomarker and imaging analyses.

These exploratory findings were consistent with the company’s proposed mechanism of macrophage reprogramming, although further clinical investigation will be needed to establish the biological relationship between these observations and treatment response.

The 12-month safety assessment identified no treatment-related serious adverse events. Reported adverse events were predominantly transient, mild-to-moderate local reactions in the treated knee, consistent with previously reported findings.

Allocetra Targets Inflammatory Mechanisms in Osteoarthritis

Allocetra is an investigational cell-based therapy developed around the modulation of macrophage activity. Macrophages regulate inflammation, tissue repair and immune responses. Their altered activity in osteoarthritis may contribute to persistent joint inflammation and tissue damage.

Osteoarthritis remains a major cause of pain and disability, particularly among older adults. Knee osteoarthritis is one of its most common forms, and treatment largely focuses on symptom management through analgesics, intra-articular injections and, in advanced cases, joint replacement surgery. No approved disease-modifying osteoarthritis drug currently addresses the underlying progression of the disease.

A therapy capable of producing sustained symptom improvement following a limited treatment course could therefore offer a different treatment approach, although Allocetra has not yet established disease-modifying efficacy.

Phase IIb Results Expected in 2027

The Phase I/IIa study included an initial open-label Phase I dose-escalation safety run-in, followed by a randomized, double-blind, placebo-controlled Phase IIa stage involving 134 patients who were randomized and treated.

Enlivex plans to present the 12-month findings at the American College of Rheumatology (ACR) Convergence 2026 in Orlando, Florida, on November 8, 2026. The poster, titled Durable Clinical Efficacy of an Innovative Intra-Articular Apoptotic Cell Therapy in Knee Osteoarthritis: Age-Related Effect Through One Year, will be presented by Prof. Philip Conaghan during Poster Session A (Abstract ID: 24454477).

The company expects topline results from its ongoing Phase IIb trial by the end of the second quarter of 2027. The study is evaluating Allocetra in the same older patient population.

The Phase IIb findings will be important in determining whether the age-related treatment response and durability observed in the smaller Phase IIa study can be reproduced in a larger clinical population.

Reference

Enlivex Announces Favorable 12-Month Topline Data from Phase I/IIa Allocetra Trial, Demonstrating Durable Treatment Response, Enlivex, 02 November 2026

Study of Intra-articular Allocetra in Knee Osteoarthritis, ClinicalTrials.gov ID NCT06233474