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Talimogene Laherparepvec

Class: Antineoplastic Agents
- Oncolytic Virus
Chemical Name: ICP34.5-ICP47-deleted herpes simplex virus 1 (HSV-1) incorporating the human GM-CSF gene
CAS Number: 1187560-31-1
Brands: Imlygic

Medically reviewed by on Dec 22, 2021. Written by ASHP.


Antineoplastic agent; a live, attenuated herpes simplex virus type 1 (HSV-1)-derived oncolytic virus encoding granulocyte-macrophage colony-stimulating factor (GM-CSF).

Uses for Talimogene Laherparepvec


Used for the local treatment of unresectable cutaneous, subcutaneous, and nodal lesions in patients with recurrent melanoma following initial surgery.

Efficacy determined based on durable response rate.

Talimogene Laherparepvec Dosage and Administration


Restricted Distribution Program

  • Available only through specialty distributors. Consult the Imlygic website for specific information ([Web]).


Intralesional Administration

Administer by intralesional injection into cutaneous, subcutaneous, and/or nodal lesions that are visible, palpable, or detectable by ultrasound guidance. Do not administer by IV injection.

Administer using a 22- to 26-gauge needle; syringes calibrated in small increments (e.g., 0.5-mL insulin syringes) recommended for better injection control.

Consult manufacturer’s labeling for detailed information on administration of talimogene laherparepvec.

Prior to administration, clean lesions and surrounding areas with alcohol and allow to dry. May administer topical or local anesthetics prior to injection of talimogene laherparepvec; however, do not inject anesthetic agents directly into lesions.

Inject talimogene laherparepvec using a single insertion point; multiple insertion points may be used if a lesion is larger than the radial reach of the needle. From the single insertion point, pull back needle without exiting the lesion and redirect along multiple tracks until the full dose has been evenly and completely dispersed within the lesion. Slowly withdraw needle from lesion to avoid leakage. Use new needle if a needle is completely withdrawn from a lesion and each time a different lesion is injected.

Apply pressure to the injection site with sterile gauze for ≥30 seconds and clean injection site and surrounding area with alcohol. Change gloves and apply an absorbent pad and dry occlusive dressing over the injected lesion(s); wipe exterior of the dry occlusive dressing with alcohol.

Syringe Preparation

Frozen suspensions of talimogene laherparepvec must be completely thawed at room temperature (20–25°C) for approximately 30 minutes in the original carton prior to administration. Do not expose to temperatures >25°C. (See Storage under Stability.)

Mix the suspension by gentle swirling; do not shake.

Withdraw appropriate volume (up to 0.1–4 mL depending on lesion size) (see Dosage under Dosage and Administration) of talimogene laherparepvec suspension into a sterile syringe with an 18- to 26-gauge needle. Replace with 22- to 26-gauge needle for intralesional injection.

Avoid aerosolization of the oncolytic virus when withdrawing the suspension into the syringe. The manufacturer recommends preparing talimogene laherparepvec in a biologic safety cabinet.

Administer immediately following preparation of syringe.

Preparation and Administration Precautions

Immunocompromised or pregnant health-care personnel should not handle talimogene laherparepvec or come into direct contact with talimogene laherparepvec injection sites, dressings, or body fluids of treated patients. (See Accidental Exposure under Cautions.)

Follow procedures for proper handling (e.g., use of gloves, protective clothing, and eyewear or face shield) and disposal of biohazard waste, including administration equipment (e.g., vial, syringe, needle, cotton gauze, gloves, masks, dressings), when preparing or administering talimogene laherparepvec. Cover open wounds prior to handling talimogene laherparepvec suspension.

If accidental occupational exposure occurs (e.g., through a splash to the eyes or mucosa), flush affected area with water for ≥15 minutes. If contact with broken skin or a needlestick injury occurs, clean affected area with soap and water and/or a disinfectant.

If spillage occurs, treat affected area with a virucidal agent (e.g., sodium hypochlorite 1%) and blot with absorbent materials.


Dosage expressed in plaque-forming units (PFU).



Use talimogene laherparepvec 1 million (1 × 106) PFU/mL for the initial treatment visit, followed 3 weeks later by talimogene laherparepvec 100 million (1 × 108) PFU/mL; administer all subsequent doses (including reinitiation of therapy) at 2-week intervals using talimogene laherparepvec 100 million PFU/mL.

Injection volume of talimogene laherparepvec depends on the lesion size (see Table 1), but do not exceed 4 mL per treatment visit for all lesions combined. If lesions are clustered together, inject the cluster as a single lesion according to the injection volumes in Table 1.

May not be possible to treat all lesions in one treatment visit or even over the full course of treatment. Give highest priority to treating the largest lesion(s) at the initial treatment visit and any new lesions (i.e., lesions that developed after the previous treatment visit) at subsequent treatment visits; prioritize remaining lesions by size until the maximum injection volume has been reached or until all injectable lesions have been treated.

Continue treatment for ≥6 months or until no injectable lesions are present.

May reinitiate therapy if new unresectable cutaneous, subcutaneous, or nodal lesions appear after a complete response was achieved.

Table 1. Injection Volume Based on Lesion Size1

Lesion Size (longest dimension)

Injection Volume

>5 cm

Up to 4 mL

>2.5–5 cm

Up to 2 mL

>1.5–2.5 cm

Up to 1 mL

>0.5–1.5 cm

Up to 0.5 mL

≤0.5 cm

Up to 0.1 mL

Prescribing Limits



Maximum injection volume of 4 mL per treatment visit for all injected lesions combined.

Special Populations

No special population dosage recommendations at this time.

Cautions for Talimogene Laherparepvec


  • Immunosuppressed individuals (e.g., those with history of primary or acquired immunodeficiencies, acquired immunodeficiency syndrome [AIDS] or other clinical manifestations of HIV infection, leukemia, or lymphoma; those receiving immunosuppressive therapy). (See Herpes Infection under Cautions.)

  • Pregnancy. (See Fetal/Neonatal Morbidity and Mortality under Cautions.)


Fetal/Neonatal Morbidity and Mortality

Potential exists for the attenuated oncolytic virus to cause serious adverse effects (e.g., multiorgan failure, death) similar to those observed in a fetus or neonate exposed to wild-type HSV-1 via placental transfer or transmission during birth.

Avoid pregnancy during therapy. (See Advice to Patients.)

Accidental Exposure

Accidental exposure may result in transmission of talimogene laherparepvec and subsequent herpes infection.

Health-care personnel, close contacts (e.g., household contacts, caregivers, sex partners, persons sharing the same bed), pregnant women, and neonates should not have direct contact with talimogene laherparepvec injection sites, dressings, or body fluids of treated patients.

Immunocompromised or pregnant health-care personnel should not prepare or administer talimogene laherparepvec.

Protective gloves should be worn when applying or changing occlusive dressings. Observe procedures for proper disposal of used dressings, gloves, and cleaning materials. (See Advice to Patients.)

If accidental exposure occurs, clean affected area with soap and water and/or a disinfectant. Monitor exposed individuals for signs and symptoms of herpes infection and initiate appropriate treatment as clinically indicated. (See Herpes Infection under Cautions and also see Advice to Patients.)

Touching or scratching injection sites or occlusive dressings may result in inadvertent transfer of talimogene laherparepvec to other areas of the body. (See Advice to Patients.)

Herpes Infection

Herpes infections, including cold sores and herpetic keratitis, reported. Life-threatening disseminated herpes infection may occur in immunosuppressed individuals. (See Contraindications under Cautions.)

Patients or close contacts with herpes-like lesions should follow standard hygienic practices to prevent virus transmission. Herpes-like lesions should be evaluated by a clinician and reported to the manufacturer at 855-465-9442; individuals may participate in follow-up testing for further characterization of the infection.

Antiviral agents active against HSV-1 (e.g., acyclovir) may affect efficacy of talimogene laherparepvec. (See Specific Drugs under Interactions.) Consider potential benefits versus risks of treating herpes infections with antiviral agents in patients receiving talimogene laherparepvec.

Injection Site Complications

Impaired healing at the injection site, cellulitis, and systemic bacterial infections reported. Necrosis or ulceration of tumor tissue may occur.

Increased risk of impaired healing at the injection site in patients with underlying risk factors (e.g., previous radiation at the injection site, lesions in poorly vascularized areas). Impaired healing at injection site resulting in infection and subsequent amputation of lower extremity occurred in one patient 6 months after talimogene laherparepvec administration; however, wound complications previously occurred in the affected area following surgery and radiation therapy.

If injection site complications, particularly necrosis resulting in open wounds, occur, practice careful wound care and infection precautions. If persistent infection or impaired healing of an injection site occurs, consider whether the benefit of continuing talimogene laherparepvec therapy outweighs the risks.

Immune-mediated Events

Immune-mediated events, including glomerulonephritis, vasculitis, pneumonitis, worsening psoriasis, and vitiligo, reported.

Before initiating talimogene laherparepvec therapy in patients with underlying autoimmune disease or continuing such therapy in patients who experience immune-mediated events, consider whether the benefit of talimogene laherparepvec outweighs the risks.


Plasmacytoma reported near an injection site in a patient with smoldering multiple myeloma.

Before initiating talimogene laherparepvec therapy in patients with multiple myeloma or continuing such therapy in patients who develop plasmacytoma, consider whether the benefit of talimogene laherparepvec outweighs the risks.

Specific Populations


May cause fetal or neonatal harm if administered to pregnant women. (See Fetal/Neonatal Morbidity and Mortality under Cautions.)


Not known whether talimogene laherparepvec is distributed into milk. Discontinue nursing or talimogene laherparepvec.

Effects of talimogene laherparepvec on nursing infants or on human milk production are unknown.

Pediatric Use

Safety and efficacy not established.

Geriatric Use

In the principal efficacy study in patients with unresectable melanoma (OPTiM study), 48% of patients receiving talimogene laherparepvec were ≥65 years of age. In clinical studies, no overall differences in safety and efficacy relative to younger adults.

Hepatic Impairment

Pharmacokinetic profile not fully established.

Renal Impairment

Pharmacokinetic profile not fully established.

Common Adverse Effects

Fatigue, chills, pyrexia, influenza-like illness, injection site pain, nausea.

Interactions for Talimogene Laherparepvec

No formal drug interaction studies to date.

Specific Drugs




Antiviral agents (e.g., acyclovir)

May interfere with efficacy of talimogene laherparepvec

Oncolytic virus is susceptible to acyclovir

Consider potential benefits versus risks of treating herpes infections with antiviral agents

Talimogene Laherparepvec Pharmacokinetics



Talimogene laherparepvec viral DNA detected in treated tumor or blood in mice up to 84 or 14 days, respectively, following last intratumor injection.



Talimogene laherparepvec viral DNA detected in blood, spleen, lymph nodes, liver, heart, and kidneys in mice; however, the highest concentrations of oncolytic viral DNA are detected in the injected tumor.

Oncolytic viral DNA not detected in bone marrow, eyes, lachrymal glands, nasal mucosa, or feces in mice after intratumor injection.

Ongoing phase 2 trial indicates presence of talimogene laherparepvec viral DNA in blood and urine in 85 and 20% of patients, respectively, following repeated intralesional administration; peak concentrations in urine detected on same day as administration.

Not known whether talimogene laherparepvec is distributed into milk.





−90 to −70°C in original carton to protect from light.

Thawed talimogene laherparepvec 1 million (1 × 106)-PFU/mL suspension: 2–8°C in original vial and carton to protect from light for 12 hours. Do not refreeze.

Thawed talimogene laherparepvec 100 million (1 × 108)-PFU/mL suspension: 2–8°C in original vial and carton to protect from light for 48 hours. Do not refreeze.


  • Talimogene laherparepvec is a preparation of live, attenuated HSV-1 with several modifications (i.e., deletion of ICP34.5 and ICP47 genes) to provide decreased pathogenicity in normal tissues, selective replication in tumor cells, tumor cell lysis, and enhanced antitumor immune response.

  • Talimogene laherparepvec virus is encoded to express GM-CSF to recruit antigen-presenting cells to the tumor microenvironment, enhance dendritic cell function, and promote cytotoxic T-cell responses to tumor-associated antigens.

  • Precise mechanism of action is unknown.

Advice to Patients

  • Importance of reading the manufacturer's medication guide before beginning treatment and each time talimogene laherparepvec is administered.

  • Risk of virus transmission. Close contacts should avoid direct contact with injection sites, dressings, or body fluids of treated patients.

  • Importance of keeping injection sites covered for at least one week following each treatment or longer if weeping or oozing occurs. Importance of replacing the dressing if it falls off.

  • Importance of not touching or scratching injection sites or occlusive dressings to prevent inadvertent transfer of talimogene laherparepvec to other areas of the body.

  • Risks associated with accidental exposure. Importance of advising patients and/or caregivers to wear protective gloves when applying or changing occlusive dressings and to dispose of used dressings and cleaning materials in a sealed plastic bag in household waste.

  • If accidental exposure occurs, importance of cleaning the affected area with soap and water and/or a disinfectant. Importance of informing clinician if herpes-like lesions occur.

  • Individuals who are pregnant or immunocompromised should not change dressings or clean injection sites.

  • Risk of fetal harm. Necessity of advising women of childbearing potential to use an effective method of contraception while receiving talimogene laherparepvec. If pregnancy occurs, advise pregnant women of potential risk to the fetus.

  • Importance of not breast-feeding during therapy.

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.

  • Importance of informing patients of other important precautionary information. (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Distribution of talimogene laherparepvec is restricted. (See Restricted Distribution Program under Dosage and Administration.)

Talimogene Laherparepvec


Dosage Forms


Brand Names



Injection, for intralesional use

1 million (1 × 106) PFU per mL



100 million (1 × 108) PFU per mL



AHFS DI Essentials™. © Copyright 2022, Selected Revisions January 1, 2016. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

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