Is Tysabri Right for You? Tysabri適合你嗎?If you are considering Tysabri (natalizumab) as a treatment for multiple sclerosis (MS), chances are that you are very familiar with one (or more) of the other disease-modifying therapies, which either didn’t reduce your relapses, or you were unable to tolerate. It’s also possible that you have not tried anything yet, but that your doctor feels that Tysabri is the place to start, due to the severity of your MS symptoms. In any case, you are different from the person who is comparing the CRAB (Copaxone, Rebif, Avonex, Betaseron) drugs and trying to decide which is right for them, and I have tried to provide as much practical information as possible to help you make your decision.當你嘗試過使用(Copaxone, Rebif, Avonex, Betaseron)這些藥物或者是其他所謂的"disease-modifying therapies(免疫抑制劑...等等之類的藥物)"都無法降低發作頻率的時候,而且你再也無法忍受MS的症狀所帶給你困擾的時候, 你就可以和醫生討論是否能夠開始使用這個藥物了.
Having set my goal as giving you the type of information that I would be interested in, I will start with my “bottom line,” summarizing my take on Tysabri. I have then compiled more detailed information, which follows.
Bottom Line: Tysabri has been shown in trials to be twice as effective as the CRABs in preventing relapses, without the flu-like symptoms of the interferons or potential disfiguration due to lipoatrophy from Copaxone. It is given only once a month by infusion in an infusion center, or in your doctor’s office (in other words, you don’t have to inject yourself). Tysabri目前在臨床上顯示了能夠比上述注射藥物好2倍的效果,而且沒有類感冒的副作用,也不會造成皮膚外觀的變形. 它只需要一個月注射一次, 是由護理人員來注射的.
The catch? PML (progressive multifocal leukoencephalopathy) which has occurred in three people taking Tysabri, resulting in two deaths and one case of severe brain damage. The estimated risk of PML is 1/1000, but is probably lower than that, as the people who had PML were also taking other immunosuppressants or modulators. Because of the risk of PML, Tysabri is recommended for people who are not responding to their first-line CRAB treatment, cannot tolerate the side effects of the treatments or have aggressive forms of relapsing MS. You may find yourself in a position to decide if Tysabri is a good choice for you. In my opinion, the real “bottom line” is how you feel about the 1/1000 statistic. Clearly, the odds are hugely in anyone’s favor that they will not get PML from taking Tysabri. However, anxiety and worry are side effects, too. If you think that even this tiny risk of PML will cause stress for you, take that seriously into your equation when deciding whether or not to start on Tysabri.風險:在Tysabri的臨床實驗中,曾經有3名患者出現了" PML 多灶性白質腦病"的情形, 有兩位死亡,一位腦部嚴重受損. 發生PML的機率約為1/1000. 也因此Tysabri才會被建議作為對(Copaxone, Rebif, Avonex, Betaseron)這些藥物沒有良好反應的病患的次要療程. 若是你認為如此小的機率都會讓你感到不安,壓力或焦慮的話,建議你一定要好好考慮是否使用此類藥物.
More Detailed Information on TysabriType of MS and Severity: Tysabri is for people with relapsing forms of MS, who have tried other disease-modifying therapies but have not had good response (meaning increasing numbers of relapses), as well as those who are unable to tolerate the other treatments (meaning they have side effects which effect quality of life or have experienced problems with liver function, thyroid, blood counts or depression).
Doctor’s Opinion: You will have to work closely with your doctor to decide if Tysabri is the right thing for you to try, as the prescribing indications of "inadequate response" or "unable to tolerate" the older CRAB drugs is a subjective decision. Also, it is not indicated specifically for relapsing-remitting MS, but for "relapsing forms of MS," meaning that some people with progressive forms of MS who still experience relapses may be candidates for Tysabri. Again, only you and your doctor can make these decisions.
Necessary Monitoring: Tysabri can only be given at an infusion center that is registered through the "TOUCH" program. "TOUCH" stands for "Tysabri Outreach: Unified Commitment to Health" and is the program that was put in place in an attempt to catch any potential cases of PML in early stages, as well as prevent them. You will be examined by a doctor or nurse and get an MRI before starting Tysabri, then examined every 3 to 6 months for neurologic changes. You will be asked to review patient safety information and fill out a short survey before each infusion.
Side Effects(副作用): Tysabri is not associated with flu-like symptoms or depression (side effects linked to interferon drugs). The side effects associated with Tysabri are:
- PML: The most serious (but rarest) risk is PML (progressive multifocal leukoencephalopathy), which can happen in people with weakened immune systems. PML can cause death or severe disability, but is rare – estimated at 1/1,000 patients.
- Common Side Effects: These include infusion-site reactions, fatigue, headaches, joint pain.
- Severe Allergic Reactions: There have been cases of allergic reactions in about 4% of patients, some requiring treatment (even hospitalization). The symptoms of this include: hives/itching, chills, dizziness, chest pain, flushing, trouble breathing and low blood pressure.
- Increased Susceptibility to Infections: People on Tysabri may be more susceptible to infections, and should take measures to avoid them, including good hand washing habits and avoiding people who are sick, when possible.
Effectiveness(成效): Basically, Tysabri is twice as effective as the CRAB drugs in reducing relapses – a 68% reduction over two years, as opposed to one-third reduction from the CRABs.
History: Tysabri has had a rocky history. It was approved fairly quickly for use in December 2004, then voluntary pulled from the market by Biogen Idec and Elan in late February 2005, just 3 months after its FDA approval. This was done after it was discovered that two people had developed PML (one fatal, one non-fatal) when using Tysabri in combination with Avonex over a 2-year period (a second PML death was later attributed to Tysabri in someone with Crohn’s disease). In Fall 2005, Tysabri was resubmitted to the FDA for "Priority Status" review. On June 5, 2006, the FDA reapproved Tysabri for use in MS under the condition that all prescribers and infusion centers, as well as patients themselves, be enrolled in the TOUCH Prescribing Program, which involves extensive education of all parties and monitoring of the patients.
Ease of Use: Unlike the CRAB drugs, Tysabri is infused in a doctor’s office or infusion center once a month, so there is no injection at home, no storage considerations and you only have to remember to get to the facility once a month.
- "Wash Out" Period: Before beginning treatment with Tysabri, patients are required to stop their current MS disease modifying treatments, as well as wait for a certain period after receiving high-dose Solu-Medrol. While the specific amount of time required to wait is determined by individual neurologists, the following rough guidelines are applied: CRAB drugs – wait 2 weeks after last dose; Solu-Medrol – wait one month after last dose; chemotherapy-based treatment – waiting time varies according to dosage, but wait at least 3 months and up to one year.
- Infusion Process: Tysabri is administered by infusion on a monthly basis in an infusion center or a doctor’s office (must be registered with the TOUCH program). The infusion process takes about 2.5 hours, as you must fill out a questionnaire and talk to a nurse prior to the infusion. The infusion itself then takes one hour and you are required to stay for one hour following the infusion for observation, as most allergic reactions happen within 2 hours of the beginning of the infusion.
Safety: The safety of Tysabri beyond 2 years is unknown.
Pregnancy and Breastfeeding: Tysabri is considered to be in "pregnancy category C," meaning that it caused some harm to fetuses in animal studies but the effect in humans is unknown. Tysabri should not be used by women who are pregnant and should be stopped for some time before trying to conceive (usually one to three months; discuss this with your doctor). Tysabri should not be used by women who are breastfeeding.
Contraindications: Clearly, Tysabri should not be taken by people with PML or who are allergic to Tysabri. Besides that, it should not be taken by patients:
- With Compromised Immune Systems: This includes people with HIV/AIDS, who have had an organ transplant, or who have a condition like leukemia or lymphoma. You should also tell your doctor if you have a recent history of frequent or recurrent infections.
- Taking Drugs that Affect the Immune System: Tysabri should not be taken if you are currently taking any drugs that may lower immune function (e.g., azathioprine, chemotherapy, cyclosporine) or immunomodulators, including the interferon-based disease-modifying therapies. (See “wash out” period explanation above.) It is extremely important that your doctor knows exactly what you are taking before you start Tysabri, including all over-the-counter medications and supplements. Do not start taking any medications during your treatment with Tysabri before asking your doctor.
Cost: About 28,400 a year for Tysabri itself, plus fees from the infusion center or doctor’s office. According to Elan's site (http://www.elan.com/), "Elan and Biogen Idec are committed to making Tysabri accessible to appropriate patients who may benefit from therapy. To achieve this goal, programs have been developed to assist patients who are uninsured or who require financial assistance. Patients who require financial assistance can receive more information by calling MS ActiveSource at 1-800-456-2255."
For more information: Tysabri is made by Biogen Idec and Elan. For more information, call 1-800-456-2255, or visit the Tysabri website.