Talimogene laherparepvec (often referred to as T-VEC) is an oncolytic virus therapy designed for the treatment of melanoma. Specifically, it's a genetically modified herpes simplex virus type 1 (the virus that causes cold sores) that has been altered to selectively replicate within tumor cells and produce a molecule called GM-CSF.

Imlygic (Talimogene laherparepvec) is a biopharmaceutical drug. It is a genetically modified form of Herpes simplex virus (HSV-1) that is made less virulent and possesses anti-cancer properties. It is the first and probably the only FDA-approved viral therapy for the treatment of melanoma [Ref].

Indications of Imlygic (Talimogene laherparepvec):

• Unresectable melanoma:
  • It is indicated for treating unresectable cutaneous, subcutaneous, and nodal lesions in patients with melanoma recurrent after the initial surgery
  • Limitations of use: Improvement of overall survival or effect on visceral metastases is not seen.

Imlygic (Talimogene laherparepvec) dose in adults:

Note:

• Talimogene laherparepvec, also called T-VEC, is given as a shot directly into certain types of cancer growths that you can see, feel, or find with ultrasound. You might not be able to inject all of the growths in one go or during all your treatments.
• So, you may need to come back for more shots to treat those growths later, whether they've already been treated before or not.

Imlygic (Talimogene laherparepvec) dose in the treatment of unresectable Melanoma:

General Guidelines:

• The most you can inject at any visit is 4 mL, no matter how many growths (lesions) you're treating.
• Keep giving these shots for at least 6 months, unless you need a different treatment or there are no more growths to treat. If new growths appear later after they were all gone, start the treatment again.

How much to inject based on the size of the growth:

• For very big growths (more than 5 cm): Up to 4 mL.
• For big growths (between 2.5 cm and 5 cm): Up to 2 mL.
• For medium growths (between 1.5 cm and 2.5 cm): Up to 1 mL.
• For small growths (between 0.5 cm and 1.5 cm): Up to 0.5 mL.
• For very small growths (0.5 cm or less): Up to 0.1 mL.

For the first shot:

• Use a version of the medicine that has 1 million units in each mL.
• You can inject up to 4 mL.
• Start with the biggest growths and move to the smaller ones.

For the second shot (3 weeks later):

• Use a stronger version of the medicine with 100 million units in each mL.
• Again, you can inject up to 4 mL.
• First treat any new growths that have appeared since the last time. Then, like before, move from the biggest to the smallest.

For every shot after that (every 2 weeks):

• Use the stronger version of the medicine (100 million units per mL).
• Treat up to 4 mL total.
• Always treat new growths first, then go from the biggest to the smallest.

This is a breakdown of the dosing instructions for T-VEC in simpler terms.

Dose in Children:

The safety and efficacy of the drug in children have not been established.

Pregnancy Risk Category: X

• If you're pregnant, don't use T-VEC.
• It's a modified herpes virus that could harm the baby, even though we aren't sure if T-VEC specifically can cross into the baby.
• Women who can get pregnant should use birth control during this treatment.
• Pregnant women shouldn't handle this medicine at all, including changing bandages or cleaning where the shot was given.
• If you're pregnant, also avoid close contact with areas where someone else got the shot.

Use of Talimogene laherparepvec during breastfeeding

• We don't know if T-VEC can be found in breast milk.
• So, if you're breastfeeding, you'll need to decide whether to stop nursing or stop taking the drug, considering how important the treatment is for you.

Dosage adjustment in renal disease:

• If you have kidney problems, there's no specific guidance from the manufacturer on adjusting the dose of T-VEC.

Dosage adjustment in liver disease:

• If you have liver problems, the manufacturer hasn't given specific instructions on how to adjust the T-VEC dose.

Common Side Effects of Imlygic (Talimogene laherparepvec):

• Central Nervous System:
  • Fatigue
  • Chills
  • Headache
• Gastrointestinal:
  • Nausea
  • Vomiting
  • Diarrhea
  • Constipation
• Local:
  • Pain At Injection Site
• Neuromuscular & Skeletal:
  • Myalgia
  • Arthralgia
  • Limb Pain
• Respiratory:
  • Flu-Like Symptoms
• Miscellaneous:
  • Fever

Uncommon Side Effects of Imlygic (Talimogene laherparepvec):

• Central Nervous System:
  • Dizziness
• Endocrine & Metabolic:
  • Weight Loss
• Gastrointestinal:
  • Abdominal Pain
• Respiratory:
  • Oropharyngeal Pain

Rare Side effects of Imlygic (Talimogene laherparepvec):

• Cardiovascular:
  • Deep Vein Thrombosis
  • Vasculitis
• Dermatologic:
  • Cellulitis
  • Dermatitis
  • Exacerbation Of Psoriasis
  • Skin Rash
  • Vitiligo
• Gastrointestinal:
  • Oral Herpes
• Infection:
  • Bacterial Infection (Systemic)
  • Herpes Virus Infection
• Ophthalmic:
  • Herpes Simplex Keratitis
• Renal:
  • Glomerulonephritis
• Respiratory:
  • Acute Asthma
  • Pneumonitis

Contraindication to Imlygic (Talimogene laherparepvec):

• People with weakened immune systems, whether from conditions like leukemia, lymphoma, AIDS, or other diseases related to HIV, or from taking medicines that suppress the immune system, should be cautious.
• Being pregnant is another factor to consider.

Warnings and precautions

Immune-mediated events

• There have been reports of the immune system reacting in unusual ways, like causing kidney issues, lung inflammation, skin changes, and other problems, after taking T-VEC.
• If someone already has auto-immune diseases or shows these unusual immune reactions after starting the drug, it's essential to weigh the pros and cons before starting or continuing T-VEC treatment.

Infection

• Taking T-VEC might lead to herpes infections like cold sores or eye infections, especially in people with weak immune systems.
• If you notice any herpes-type sores, take usual precautions to avoid spreading the virus and contact a doctor.
• If you think you have such sores after taking T-VEC, also call the drug company, Amgen, at 1-855-465-9442.

Complications at the injection site:

• Some people have had problems at the spot where T-VEC was injected, like sores that don't heal well, skin death, or infections.
• If the skin dies and leaves an open sore, it's essential to be very careful to avoid infections.
• People who've had radiation treatments in that area or have poor blood flow to the area might have a higher risk of these problems.
• In fact, one person even had to have their leg amputated because of an infected sore that didn't heal.
• It's crucial to watch these injection spots closely.
• If someone has ongoing infections or sores that don't heal, you'll need to think hard about the pros and cons of continuing the T-VEC treatment.

Toxicity in the lungs:

• T-VEC treatment has sometimes led to breathing problems.
• Be extra careful if giving the injection near the big air tubes in the lungs.
• If you're treating spots close to these areas, talk to a doctor about the risks.

Multiple myeloma

• In a study, a person with an early stage of multiple myeloma got a tumor growth near where T-VEC was injected.
• If someone has multiple myeloma or gets this kind of tumor during treatment, think carefully about the pros and cons of continuing with T-VEC.
• It's a good idea to discuss with a doctor.

Talimogene laherparepvec: Drug Interaction

Monitoring parameters:

Herpetic Infections:

• Watch for:
  • Cold sores
  • Eye infections related to herpes (herpetic keratitis)

Injection-Site Problems:

• Look for:
  • Sores or wounds that don't heal
  • Skin changes or damage at the injection site

Breathing Problems:

• Be alert for signs of:
  • Difficulty breathing
  • Obstructive airway disease

Immune System Reactions:

• Keep an eye out for:
  • Unusual immune reactions
  • Signs of the body attacking its own cells or tissues

How to administer Imlygic (Talimogene laherparepvec)?

Preparation:

• Treat only the skin or lymph node growths that you can see, feel, or spot with ultrasound.
• Clean the area around the growth with alcohol and let it dry.
• If needed, use pain relief cream or shots, but don't put them directly into the growth (only around it).

Injection Steps:

• Using a thin needle (22 to 26 gauge), insert it once into the growth.
• Push the needle in different directions inside the growth to spread the medicine.
• If the growth is big, use more than one entry point.
• While keeping the needle inside, pull it back a bit and redirect to inject the medicine everywhere in the growth.
• Pull out the needle slowly to prevent any leakage.
• If you're treating more than one growth, use a new needle for each one.

After Injection:

• Press a clean cloth on the spot for 30 seconds.
• Clean the spot and surrounding area with alcohol.
• Put on a new pair of gloves.
• Cover the spot with a pad and sealed dressing, then clean the outside of the dressing with alcohol.
• Keep the spot covered for at least a week or until there's no more leakage. Replace if it falls off.

Safety Precautions:

• If you have a weak immune system or are pregnant, don't handle or give this medicine. Also, avoid touching treated spots or related materials.
• Wear protective gear while giving the shot to prevent any accidents.
• After treatment, patients should seal used materials in a plastic bag and throw them in the regular trash.

Always ensure you're working in a safe and sterile environment.

Mechanism of action of Talimogene laherparepvec (Imlygic):

• Talimogene laherparepvec is a virus made from a modified herpes simplex virus 1 (HSV).
• This virus is designed to target and destroy cancer cells.
• They modified it by removing two nonessential viral genes.
• One deletion makes the virus less harmful to the body while still attacking tumors.
• The other deletion helps the body's immune system recognize and fight the cancer.
• Additionally, the virus produces a substance called GM-CSF that brings in immune cells to attack the tumor.
• This treatment aims to trigger the body's immune response to fight against the cancer.

Time to reach peak:

• The highest amount of T-VEC is found in the urine on the same day it's given as a treatment.

International Brands of Talimogene laherparepvec:

• Imlygic

Talimogene laherparepvec Brand Names in Pakistan:

Not available.