# Safety, Feasibility, and Preliminary Efficacy of Allogeneic MSCs to Treat Advanced Femoral Head Osteonecrosis (ALOFEM): A Pilot Study in Young Onco‐Hematological Patients

## TL;DR

This pilot study explores using allogeneic MSCs to treat severe femoral head osteonecrosis in young patients, showing it is feasible and safe with some early signs of efficacy.

## Contribution

Demonstrates the long-term safety and feasibility of allogeneic MSCs in treating ONFH in young onco-hematological patients.

## Key findings

- Allogeneic MSC implantation was feasible and safe with no serious adverse events up to 4 years.
- Five out of seven hips avoided total hip replacement at 4 years.
- Early efficacy was observed but not statistically significant.

## Abstract

Severe osteonecrosis of the femoral head (ONFH) secondary to corticosteroid therapy in symptomatic, hematological young patients currently has no therapeutic alternative, and early total hip replacement (THR) is a high‐risk intervention in those patients.

To evaluate feasibility, safety, and early efficacy of allogeneic expanded mesenchymal stromal cells (MSCs) in a pilot clinical trial.

Pilot phase 1 open, noncontrolled, nonrandomized clinical trial evaluating the bone regeneration capacity in seven hips from four patients (young females 11–19 year old) with symptomatic, severe bilateral femoral head osteonecrosis (secondary to corticosteroid therapy), 1 year after being surgically treated with 140 × 106 allogenic MSC plus forage.

The proposed therapy proved feasibility, safety at 1 and 4 years (no related serious adverse events [SAEs]), and early efficacy (nonsignificant) in the case analysis (5/7 hips avoiding THR at 4 years).

The implantation of expanded allogeneic MSC in young patients to prevent conversion to a THR or collapse of the femoral head due to severe osteonecrosis is feasible without safety concerns in the longer‐term follow‐up (FU) upto 4 years.

Trial Registration: EudraCT number: 2018‐000886‐35