Important Safety Information

What is LENMELDY?

LENMELDY is a one-time gene therapy developed to treat children with pre-symptomatic late infantile, pre-symptomatic early juvenile and early symptomatic early juvenile, referred to as early-onset, metachromatic leukodystrophy (MLD). MLD is caused by a defect in the arylsulfatase A (ARSA) gene, which causes the body to produce reduced or no ARSA enzyme. LENMELDY is made specifically for each child, using the child’s own blood stem cells, and adding functional copies of the ARSA gene to their cells. This may allow the child to produce sufficient ARSA enzyme to stop or slow the progression of MLD symptoms.

What is the most important information I should know about LENMELDY?

The most common side effects you should be aware of with LENMELDY are:

• Fever
• Swelling or sores inside the mouth
• Reduction in blood clotting ability and possibility of excess bleeding due to a lower level of platelets
• Increased risk of infection due to decreased level of white blood cells (WBC)

Call your doctor right away if the child has new or unusual bleeding, which may include any of these signs or symptoms:

• Severe headache
• Abnormal bruising
• Nosebleed
• Blood in urine, stool, or vomit
• Coughing up blood
• Unusual stomach or back pain

The child may experience side effects with medicines administered as part of the LENMELDY treatment regimen. Your doctor may give other medicines to treat the side effects.

After treatment with LENMELDY, the child may experience low blood counts. This can put the child at greater risk for bleeding and/or infection. Your doctor will monitor the child and may provide other treatment until their blood counts return to safe levels.

Children treated with LENMELDY may experience serious or life-threatening infections, including infections of the bloodstream by bacteria or viruses. Most infections occur in the first 1 or 2 months after treatment with LENMELDY but can occur >1 year later. Tell your doctor right away if the child develops fever, chills, or any signs or symptoms of an infection.

Children treated with LENMELDY may experience Veno-Occlusive Disease (VOD), or blocking of veins to the liver, causing damage to the liver. Your doctor will monitor the child for signs and symptoms of VOD during the first month after LENMELDY infusion.

The child will need to be monitored annually, at a minimum, for at least 15 years. This is necessary to ensure there are no changes to their blood panel as there is a potential risk of blood cancer associated with this treatment; it should be noted that no such cases have been reported in clinical studies of LENMELDY.

If the child is diagnosed with cancer, have your doctor contact Orchard Therapeutics at 1-888-878-0185.

How will the child receive LENMELDY?

As part of the LENMELDY treatment regimen, your doctors will prescribe additional medications to prepare the child’s body for LENMELDY. This will include administration of chemotherapy. It is important to talk to your doctor about their therapy to be fully informed of all risks and benefits of treatment.

Treatment with chemotherapy is associated with several unique risk factors. One specific side effect involves fertility; after receiving chemotherapy, it may not be possible for the child to become pregnant or father a child. You should consider discussing options for fertility preservation with your doctor before treatment.

STEP 1: LENMELDY is made specifically for the child from their own blood stem cells. Your doctor will collect their blood stem cells through a process called mobilization and apheresis (A-feh-REE-sis). This process takes one or more days to collect enough blood stem cells to make LENMELDY.

STEP 2: The child’s blood stem cells will be sent to a drug manufacturing site where they are used to make LENMELDY. It takes approximately 6 to 8 weeks from the time their cells are collected to manufacture and test LENMELDY before it is shipped to your doctor, but the time may vary.

STEP 3: Before the child receives LENMELDY, your doctor will give them chemotherapy for a few days to prepare their bone marrow to accept the new cells. The child will be admitted to a qualified treatment center (QTC) for this step and remain in the QTC for LENMELDY infusion.

STEP 4: LENMELDY is given by intravenous infusion (into a vein). The child may receive more than one bag of LENMELDY. Each bag is infused in about 30 minutes.

After the LENMELDY infusion, the child will stay in the QTC for approximately 4-12 weeks so that the healthcare team can closely monitor their recovery. Your doctor will determine when the child can go home.

What should the child avoid after receiving LENMELDY?

• Do not donate blood, organs, tissues, or cells

What are additional possible or reasonably likely side effects of LENMELDY?

While receiving chemotherapy to prepare the child’s body for LENMELDY:

• Chemotherapy is administered to prepare their bone marrow to accept LENMELDY. Chemotherapy is often associated with a variety of side effects, including:
  • Nausea
  • Vomiting
  • Decreased appetite
  • Constipation
  • Abdominal pain
  • Headache
  • Rash

Following treatment

• Blood issues

Once the child has completed their treatment regimen, they may experience low blood counts. This may put them at greater risk of bleeding and/or infection.

Until the child’s blood counts (platelets, white blood cells, red blood cells) return to safe levels, they may be treated with blood and platelet transfusions and other medicines that prevent bleeding and infection by increasing blood counts.

Most children’s blood counts return to safe levels about one month after treatment with LENMELDY. However, some blood counts may not recover for >1 year.

• Life-threatening infections

Treatment with LENMELDY may cause serious or life-threatening infections, including infections of the bloodstream by bacteria or viruses.

Most infections occur in the first 1 or 2 months after treatment with LENMELDY but can occur >1 year later. Tell your doctor right away if the child develops fever, chills, or any signs or symptoms of an infection.

LENMELDY will not give the child human immunodeficiency virus (HIV) infection. Treatment with LENMELDY may cause a false-positive HIV test result by some commercial tests. If the child needs an HIV test, talk with your doctor about the appropriate test to use.

• Other issues

Inflamed and painful mouth (typically occurs during the first 2 months after LENMELDY), nausea, vomiting, decreased appetite, constipation, abdominal pain, diarrhea, headache, and new onset seizures may occur.

Treatment with LENMELDY may cause brain inflammation. Tell your doctor right away if the child develops weakness, decreased muscle tone, loss of mental clarity, vomiting, and swallowing difficulties.

As always, tell your doctor right away if the child gets a fever, is feeling tired, or experiences easy bleeding or bruising.

It is important that the child has regular check-ups with your doctor, including at least annual blood tests, to detect any adverse effects and to confirm that LENMELDY is still working. Talk to your doctor about any concerns.

Please see the full Prescribing Information for LENMELDY.

These are not all the possible side effects of LENMELDY. Call your doctor for medical advice about side effects. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.