On May 17, 2023, San Francisco City Attorney David Chiu announced Walgreens agreed to pay the People of San Francisco $230 million for its role…
Read MoreWe are no longer accepting new cases.
Lemtrada Lawsuits
Weitz & Luxenberg is currently taking cases for lawsuits filed on behalf of MS patients that experienced any of the following within three days of a Lemtrada infusion:
- Ischemic stroke.
- Hemorrhagic stroke.
- Head or neck (cervicocephalic) arterial dissection.
- Death due to any of these complications.
If you or a loved one suffered from any of these serious side effects resulting from Lemtrada, you may be entitled to compensation for medical expenses, pain and suffering, lost wages, and other potential claims.
Patients deserve to know the risks of the treatments they undergo. Pharmaceutical manufacturers such as Sanofi Genzyme that fail to thoroughly warn regarding the safety of their drugs must be held accountable.
What Is Lemtrada?
Lemtrada (alemtuzumab) is a drug indicated for treatment of relapsing forms of multiple sclerosis (MS). MS is an autoimmune disease that damages the nervous system.

In patients with MS, the immune system attacks the myelin, a fatty substance that protects and insulates nerve fibers in the brain and spinal cord. This myelin deterioration leads to disrupted communication between nerves, causing a variety of neurological symptoms.
Lemtrada is administered by intravenous (IV) infusion in two treatment courses, a year apart. The first treatment course is 12mg/day for five days. The second course, 12 months later, is 12mg/day for three days. (1)
FDA Warns of Risk of Stroke and Head and Neck Arterial Dissection
In November of 2018, the U.S. Food and Drug Administration (FDA) issued a safety announcement that “serious cases of stroke and tears in the lining of arteries in the head and neck” had occurred in patients with multiple sclerosis after they received Lemtrada. The FDA went on to warn, “These problems can lead to permanent disability and even death.” (2)
The safety announcement was prompted by the FDA receiving 13 cases of stroke (an interruption to blood flow in the brain) and cervicocephalic arterial dissection (a tear in the lining of the artery in the head or neck). All except for one case “reported symptoms within 1 day of receiving Lemtrada” and all reported strokes and head or neck arterial dissections occurred within three days of receiving Lemtrada. (3)
These 13 cases were reported to the FDA Adverse Event Reporting System (FAERS) database.
To address the safety concerns raised by these cases, the FDA: (4)
- Added a new warning to the Lemtrada label about these risks.
- Added a new warning to the patient medication guide.
- Updated the Lemtrada black box warning to include the risk of stroke. (5)
A black box warning is the FDA’s most serious warning. It is only used for serious or life-threatening risks.(6)
Symptoms of Stroke and Head and Neck Arterial Dissection
Symptoms of stroke and head and neck arterial dissection include sudden onset of:
- Numbness or weakness in the face or limbs, particularly on one side.
- Confusion or difficulty understanding other people.
- Trouble speaking.
- Vision problems.
- Loss of balance and coordination, difficulty walking.
- Severe headache or neck pain.
- Dizziness. (7)
Time is of the essence in treating strokes or arterial dissections. Prompt treatment can limit lasting damage. Call 911 immediately if you suspect either of these problems.
Serious Side Effects Can Lead to Permanent Disability and Death
Case reports in the medical literature link Lemtrada with the potentially fatal side effects of ischemic stroke, hemorrhagic stroke, and head or neck (cervicocephalic) arterial dissection. (8) (9) (10) (11)
An ischemic stroke occurs when a blood clot blocks a blood vessel that carries blood to the brain. (12) A hemorrhagic stroke occurs due to bleeding in blood vessels inside the brain or outside the brain, but within the skull. Bleeding inside the brain is called intracranial hemorrhage (ICH), and bleeding that occurs between the brain and the tissue covering the brain, known as the dura mater, is called a subarachnoid hemorrhage. (13)
Head or neck arterial dissection occurs when the lining of an artery tears in the head or neck. These tears can cause the artery to narrow or close off entirely, causing a stroke. (14)
Strokes and arterial dissections can result in serious complications and disabilities, including:
- Death.
- Recurrent stroke.
- Seizure.
- Pain and weakness.
- Numbness and/or paralyzed limbs.
- Falls.
- Pneumonia.
- Vision loss.
- Motor disorders and inability to carry out everyday tasks.
- Memory and attention problems.
- Bed sores.
- Incontinence.
- Language disorder (aphasia) or speech loss.
- Anxiety and depression. (15) (16) (17) (18) (19)
Following the FDA’s safety announcement, a neurologist identified five more cases of intracerebral hemorrhage in MS patients receiving Lemtrada. All experienced the ICH during the initial 5-day infusion period, and none had a prior history of bleeding disorder, stroke, aneurysm, or other risk factors for ICH. (20)
In April of 2019, the European Medicines Agency has restricted the use of Lemtrada while it performs a safety review. (21) (22)
How Weitz & Luxenberg Can Help
W&L’s Drug and Medical Devices Litigation Unit attorneys have decades of specialized experience with complex pharmaceutical lawsuits. We can help you evaluate your circumstances and explore your legal options.
Led by Ellen Relkin, our team for defective drugs and medical devices has secured more than $12 billion in verdicts and settlements in the last 30 years on behalf of patients harmed by defective drugs and medical devices. We are committed to holding drug and device manufacturers accountable for the harm they cause.