06 SPEECH SUMMARY – PROF. LUCIO ROVATI

Today, with two such important studies published in the top international scientific jounals, there is no more doubt that the long-term use of glucosamine sulfate with years of therapy can control the symptoms, reduce the pain, and above all improve joint function. Secondary analyses of the data have shown that these benefits can be obtained regardless of patient’s age and disease severity.
In both studies, glucosamine sulfate was able to slow the progression of structural joint damage in patients aged 60-65 on average (the age group most commonly affected) and with moderate severity of the disease. In the few patients with very severe osteoarthritis, the disease obviously does not progress much and therefore the activity of the drug is less pronounced, even if a benefit cannot be excluded.
The certainty today considering the two studies is that patients with mild or moderate osteoarthritis can use the drug to retard disease progression. For patients with more severe disease it is unclear if it is possible to reverse the structural damage. Nonetheless in these cases it is possible to act on symptoms that, after treatment, do not get worse but rather improve in a relevant manner.
Long-term symptom control –associated with a tolerability profile similar to that of the placebo – is in itself an important result. Indeed, the anti-inflammatory drugs used for standard treatment of the disease, including the new cox 2 inhibitors, have less gastrointestinal side effects but may provoke severe adverse events involving the cardiovascular system. In contrast, glucosamine sulfate has shown, along with good tolerability, an effective ability to control symptoms without the need to add any other drug, except when an acute relapse typical of the natural history of the disease occurs.
Today there is a clear indication: it is the second time that we observe, using the same parameters, a slower progression and even a block of the structural joint damage. This is the primary objective of the fight against arthritis, because once the joint is deteriorated, the disease inevitably progresses leading to invalidity. If we can contain the worsening of structural damage, we should be able to slow or even abolish the progression of disability. Even in those patients who already have a severe structural compromise, and in whom the benefit on symptoms prevails, this can in any case delay the onset of invalidity.

As a coauthor of both studies, I can state that the second is better than the first. In the study by prof. Pavleka, disease progression has been monitored more closely over the 3 years of follow-up, performing x rays every year in all patients enrolled. In addition, we have not only assessed a main parameter, that is, the space between the two bones forming the joint, which is normally occupied by cartilage. We have also assessed a parameter that relates to the reaction of the bone, the formation of osteophytes, that is the parts of the bone protruding inside the joint of patients with arthritis. Actually, very few patients treated with glucosamine sulfate showed a worsening of the osteophytes, which occurred three times as much as in patients who received placebo. This is particularly important because the degree of ostephytosis is predictive of pain progression over time.
We have also expanded our observations regarding symptoms. Therefore the new study not only confirms the exciting preliminary data from Prof. Register, but expands them with more systematic and detailed observations.
Certainly the research on osteoarthrisis cannot stop and will continue. It is important to look further, obtain longer follow-up data and assess if we can limit invalidity and the need for prosthetic surgery, as these data may lead to hope.
For the future we are thinking about a study to evaluate how many joint replacements can be avoided using glucosamine sulfate. But before getting to that, it is necessary that the international scientific community reaches an agreement on which parameters to evaluate when deciding to perform the intervention, a problem that currently depends not only on the patient’s conditions but also on the surgeon’s disposition and the health service resources. Scientist should thus define clear indication for prosthetic surgery. This task is being performed by a group of european experts who will define the necessary parameters.