Thursday, October 20, 2011

No time to waste on drugs that aren't working: Determining who is a "non-responder" early in the game


Writer, ms.about.com

When we start our disease-modifying therapy, it is with the hopes that it is going to stop (or at least drastically reduce) our MS relapses and/or progression of disease. For some of us, a certain therapy works and for others it doesn't.

However, since MS is a chronic disease that is extremely unpredictable, we often don't know if our DMTs are working or not. Unlike an antibiotic prescribed for a bacterial infection (where a blood test and clinical symptoms can pretty clearly determine if the infection is cured or not), the determination is usually made for DMT efficacy when the drugs are decidedly not effective against our MS – in other words, we have relapses, accumulate disability and show worsening MRI results while we are still taking the drugs. At a certain point, we are classified as "non-responders" to that drug and switched to another medication.

However, this may not happen quickly and we may be taking a treatment that is not effective for many years before the determination is made that it has not been working for us. Not only have we unnecessarily incurred expenses and injected ourselves, we have also potentially wasted time that we could have been on treatment that would have actually slowed down the MS.

Dr. Mar Tintoré, of Barcelona, Spain, in her presentation, "Detecting Therapeutic Response Using Early Clinical Signs and MRI," followed a group of patients for 2 years to find out if they could proactively identify "non-responders" to therapy.

They found that if an MRI taken at 12 months after starting treatment showed 2 or more active lesions, then that person was 8.3 times more likely to be a non-responder.

Moreover, the people on DMTs who had 2 or more new or enlarging lesions after 2 years of therapy had significantly more disability. The researchers found that if people on therapy are having at least 2 of the 3 signs of disease activity (relapses, more disability or MRI activity) after 12 months of treatment, they will continue to have these things and disability will accumulate.

Likewise, an Italian study, presented by Dr. Romeo, looked at MRI scan taken within 6 to 12 months of initiating treatment and found that the presence of more than 2 active lesions within that time meant that the person was more than 4 times as likely to be a "non-responder." In this study, non-responder was defined as a person who showed at least a 1.5 increase on the EDSS within 5 years.

What does this mean? Considering this data, it seems logical that a protocol would be developed whereby people starting a certain disease-modifying therapy receive an MRI within a year of initiation. If a certain level of activity is seen, serious consideration should be given to switching the person to a different DMT. However, according to Dr. Tintoré, at the moment, if a patient is completely stable clinically, but shows MRI activity, treatment is NOT changed.

Many new drugs are coming down the pipeline, which will soon be available to patients and docs. As Dr. Tintore states: "It is our responsibility to decide early which patients are good responders to medications."  She continued, "We need to standardize our definition, as the group of non-responders can be as low as 7% or as high as 45% in the same group of patients, depending on the definition of non-responder that we use." According to Dr. TintorĂ©, the ultimate goal is to find the right treatment for each of our patients. Amen to that.

1 comment:

  1. I agree with Dr. Tintore. In my side, I think pharmacies need to develop personalized drugs to increase the efficiency of the clinic medicine used and bring the number of non-responders down to at least 10%.
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