11 Aug 2016
Mesoblast Ltd has announced that data from a mid-stage trial for its experimental stem-cell therapy indicated that the therapy significantly alleviated symptoms and disease activity in rheumatoid arthritis (RA) patients who have stopped responding to commercially available biotech drugs. The findings hold numerous implications in the development of new, effective therapeutic approaches to rheumatoid arthritis.
A new method of combating RA
The symptoms and progression of RA are caused by pro-inflammatory white blood cells and activated T cells of the immune system. These trigger multiple pro-inflammatory cytokine pathways; that is, they activate many kinds of small proteins which signal to the cells to become inflamed. In other words, there is more than one way to transmit the message to the cells to get inflamed.
Existing therapies each target one way of transmitting the ‘inflammation message’ by inhibiting one type of protein, but none target more than one at the same time. Mesoblast’s treatment, on the other hand, inhibits multiple types of proteins that cause inflammation. Therefore, the patient experiences significant relief from the symptoms.
Hope for those who stopped responding to conventional drugs
Treatment with the Melbourne-based company involved the intravenous delivery of MPC-300-IV, a tier 1 product candidate consisting of 300 million Mesenchymal Precursor Cells (MPCs). The results of their 48-patient, 12-week Phase 2 trial have deemed the treatment to be well-tolerated with no serious side-effects nor any infusion-related accidents.
ACR is a scale to measure change in symptoms of RA. If patients experience a 20% relief of RA symptoms, the trial is said to have achieved ACR20. In patients who had previously been treated with at least one biologic drug, ACR20 was achieved by 55% of those who had received an infusion of 2 million cells per kilogram of their weight. In patients who had received treatment from at least one biologic drug without the infusion, only 33% achieved ACR20.
There is a term used to refer to a higher degree of improvement, ACR70, when patients report a 70% relief from RA. This was achieved by 36% after a single infusion of the Mesoblast treatment, compared to the placebo group which obviously showed no improvement. The biotechnology company also claims that the cell therapy improved patients’ physical function and reduced overall disease activity.
According to a statement made by Dr Allan Gibofsky, a rheumatologist at the Hospital for Special Surgery, New York, Mesoblast’s cell infusion therapy has ‘the potential to fill the major unmet medical need’ for patients that gain no benefit from popular biological treatments. The effects of new treatment methods for RA must be twofold – alleviating pain from RA and stopping the disease from getting worse simultaneously.