Administration and Handling of Talimogene Laherparepvec: An Intralesional Oncolytic Immunotherapy for Melanoma

Beyond PD-1 Immunotherapy in Malignant Melanoma

For many years, the standard therapy for malignant melanoma was based mainly on surgical resection. Unfortunately, this treatment is curative only in the early localized stage of this malignancy. The metastatic stage of malignant melanoma still remains a huge therapeutic challenge. Despite the many new therapeutic options that have become available over the last years, there is a constant need for safer and more effective treatment modalities. There has been a dynamic development of various anti-cancer immunotherapies directed against new molecular targets. A number of clinical trials are currently being conducted to confirm their effectiveness and safety. In this review of the literature, we summarize the contemporary knowledge on promising new immunotherapies beyond the currently available treatment options for malignant melanoma, including oncolytic immunotherapy, selective inhibitors of indoleamine 2,3-dioxygenease, anti-PD-(L)1 (programmed death ligand 1) drugs, immune checkpoint protein LAG-3 antibodies, inhibitors of histone deacetylase (HDAC) and inhibitors of B7-H3.

Talimogene laherparepvec: review of its mechanism of action and clinical efficacy and safety

Intratumoral immunotherapy inhibits tumor growth by killing injected tumor cells, thus initiating local and systemic immune responses. Oncolytic viruses are a novel class of intratumoral immunotherapies that show promise for treating solid tumors. Talimogene laherparepvec is a first-in-class, genetically modified, herpes simplex virus type 1-based oncolytic immunotherapy approved for the local treatment of unresectable cutaneous, subcutaneous and nodal lesions in patients with melanoma recurrent after initial surgery. This review highlights the dual mechanism of action for talimogene laherparepvec (direct tumor cell lysis and stimulation of local response in tumor microenvironment and systemic immune response in distant metastases), summarizes key preclinical and clinical trials evaluating efficacy and safety of talimogene laherparepvec in melanoma, and describes studies ongoing in other solid tumors.

Randomized, Open-Label Phase II Study Evaluating the Efficacy and Safety of Talimogene Laherparepvec in Combination With Ipilimumab Versus Ipilimumab Alone in Patients With Advanced, Unresectable Melanoma

Purpose

We evaluated the combination of talimogene laherparepvec plus ipilimumab versus ipilimumab alone in patients with advanced melanoma in a phase II study. To our knowledge, this was the first randomized trial to evaluate addition of an oncolytic virus to a checkpoint inhibitor.

Methods

Patients with unresectable stages IIIB to IV melanoma, with no more than one prior therapy if BRAF wild-type, no more than two prior therapies if BRAF mutant, measurable/injectable disease, and without symptomatic autoimmunity or clinically significant immunosuppression were randomly assigned 1:1 to receive talimogene laherparepvec plus ipilimumab or ipilimumab alone. Talimogene laherparepvec treatment began in week 1 (first dose, ≤ 4 mL × 106 plaque-forming units/mL; after 3 weeks, ≤ 4 mL × 108 plaque-forming units/mL every 2 weeks). Ipilimumab (3 mg/kg every 3 weeks; up to four doses) began week 1 in the ipilimumab alone arm and week 6 in the combination arm. The primary end point was objective response rate evaluated by investigators per immune-related response criteria.

Results

One hundred ninety-eight patients were randomly assigned to talimogene laherparepvec plus ipilimumab (n = 98), or ipilimumab alone (n = 100). Thirty-eight patients (39%) in the combination arm and 18 patients (18%) in the ipilimumab arm had an objective response (odds ratio, 2.9; 95% CI, 1.5 to 5.5; P = .002). Responses were not limited to injected lesions; visceral lesion decreases were observed in 52% of patients in the combination arm and 23% of patients in the ipilimumab arm. Frequently occurring adverse events (AEs) included fatigue (combination, 59%; ipilimumab alone, 42%), chills (combination, 53%; ipilimumab alone, 3%), and diarrhea (combination, 42%; ipilimumab alone, 35%). Incidence of grade ≥ 3 AEs was 45% and 35%, respectively. Three patients in the combination arm had fatal AEs; none were treatment related.

Conclusion

The study met its primary end point; the objective response rate was significantly higher with talimogene laherparepvec plus ipilimumab versus ipilimumab alone. These data indicate that the combination has greater antitumor activity without additional safety concerns versus ipilimumab.

Implementing a Program of Talimogene laherparepvec

BACKGROUND

Oncolytic viruses are genetically engineered or naturally occurring viruses that selectively replicate in cancer cells without harming normal cells. Talimogene laherparepvec (Imlygic^®), the first oncolytic viral therapy approved for treatment of cancer, was approved for treatment of locally advanced melanoma in October 2015.

PURPOSE

As a biologic product, use of T. laherparepvec in the clinical setting requires pretreatment planning and a unique systematic approach to deliver the therapy. The processes we describe herein could be adopted by other centers that choose to prescribe T. laherparepvec.

METHODS

We studied our clinical trial experience with T. laherparepvec before we embarked on using commercially available T. laherparepvec. We created a standard operating procedure (SOP) with multidisciplinary buy-in and oversight from leadership in Infection Control at our institution. We reflected on clinical cases and the actual procedures of administering T. laherparepvec to create the SOP.

RESULTS

The preimplementation planning, patient selection, identification of lesions to treat, the actual procedure, and ongoing assessment of patients are described. Tumoral-related factors that lead to unique challenges are described.

CONCLUSIONS

A process to ensure safe and responsible implementation of a program to administer T. laherparepvec for treatment of melanoma may improve the quality of treatment for patients who suffer from advanced melanoma.

Pharmacy Operationalization of the Intralesional Oncolytic Immunotherapy Talimogene Laherparepvec

Objective: Oncolytic immunotherapy involves the use of viruses to target and destroy cancer cells and to induce immune responses for an enhanced antitumor effect. Talimogene laherparepvec, a genetically modified herpes simplex virus type 1 (HSV-1) that selectively replicates in tumors to induce lytic cell death, tumor antigen release, and the local production of granulocyte-macrophage colony-stimulating factor (GM-CSF), has been approved for the treatment of a defined population of patients with metastatic melanoma. Talimogene laherparepvec is administered as a series of intralesional injections, and specific procedures are implemented to minimize the risk of viral exposure. Because talimogene laherparepvec represents a novel therapeutic modality, its preparation, administration, and handling requirements differ from current therapies; pharmacists have an important role in developing new procedures to incorporate it into clinical practice. Methods: In this review, pharmacists with experience dispensing talimogene laherparepvec, in the clinical trial setting and/or as a commercially available product at US academic institutions, synthesized their personal experiences through group discussions to provide insights on the ordering, receipt, storage, preparation, administration, and handling of talimogene laherparepvec. Results: Suggestions for patient education and practical guidance to assist hospital pharmacists and decision makers with implementing talimogene laherparepvec at their institutions are provided. Conclusion: These insights may further inform the development of policies or procedures to incorporate talimogene laherparepvec into clinical settings and improve patient outcomes.

Cancer Immunotherapy: An Evidence-Based Overview and Implications for Practice

BACKGROUND

Significant research progress has been made in immunotherapies since the mid-1990s, and this rapid evolution necessitates evidence-based education on immunotherapies, their pathophysiology, and their toxicities to provide safe, effective care.
.

OBJECTIVES

The aim of this article is to provide an evidence-based overview, with implications for practice, of checkpoint inhibitors, monoclonal antibodies, oncolytic viral therapies, and chimeric antigen receptor T-cell therapies.
.

METHODS

Each immunotherapy category is presented according to the pathophysiology of its immune modulation, the classes of agents within each category, evidence-based toxicities associated with each class, and implications for practice.
.

FINDINGS

Immunotherapies vary in their pathophysiology and offer potential to be highly effective for the management of a wide array of cancer types. Understanding the unique pathophysiology and toxicities is necessary to assess, manage, and provide safe, effective patient-focused care.

Randomized, Open-Label Phase II Study Evaluating the Efficacy and Safety of Talimogene Laherparepvec in Combination With Ipilimumab Versus Ipilimumab Alone in Patients With Advanced, Unresectable Melanoma

Purpose We evaluated the combination of talimogene laherparepvec plus ipilimumab versus ipilimumab alone in patients with advanced melanoma in a phase II study. To our knowledge, this was the first randomized trial to evaluate addition of an oncolytic virus to a checkpoint inhibitor. Methods Patients with unresectable stages IIIB to IV melanoma, with no more than one prior therapy if BRAF wild-type, no more than two prior therapies if BRAF mutant, measurable/injectable disease, and without symptomatic autoimmunity or clinically significant immunosuppression were randomly assigned 1:1 to receive talimogene laherparepvec plus ipilimumab or ipilimumab alone. Talimogene laherparepvec treatment began in week 1 (first dose, ≤ 4 mL × 10⁶ plaque-forming units/mL; after 3 weeks, ≤ 4 mL × 10⁸ plaque-forming units/mL every 2 weeks). Ipilimumab (3 mg/kg every 3 weeks; up to four doses) began week 1 in the ipilimumab alone arm and week 6 in the combination arm. The primary end point was objective response rate evaluated by investigators per immune-related response criteria. Results One hundred ninety-eight patients were randomly assigned to talimogene laherparepvec plus ipilimumab (n = 98), or ipilimumab alone (n = 100). Thirty-eight patients (39%) in the combination arm and 18 patients (18%) in the ipilimumab arm had an objective response (odds ratio, 2.9; 95% CI, 1.5 to 5.5; P = .002). Responses were not limited to injected lesions; visceral lesion decreases were observed in 52% of patients in the combination arm and 23% of patients in the ipilimumab arm. Frequently occurring adverse events (AEs) included fatigue (combination, 59%; ipilimumab alone, 42%), chills (combination, 53%; ipilimumab alone, 3%), and diarrhea (combination, 42%; ipilimumab alone, 35%). Incidence of grade ≥ 3 AEs was 45% and 35%, respectively. Three patients in the combination arm had fatal AEs; none were treatment related. Conclusion The study met its primary end point; the objective response rate was significantly higher with talimogene laherparepvec plus ipilimumab versus ipilimumab alone. These data indicate that the combination has greater antitumor activity without additional safety concerns versus ipilimumab.

Oncolytic Virotherapy Promotes Intratumoral T Cell Infiltration and Improves Anti-PD-1 Immunotherapy

Here we report a phase 1b clinical trial testing the impact of oncolytic virotherapy with talimogene laherparepvec on cytotoxic T cell infiltration and therapeutic efficacy of the anti-PD-1 antibody pembrolizumab. Twenty-one patients with advanced melanoma were treated with talimogene laherparepvec followed by combination therapy with pembrolizumab. Therapy was generally well tolerated, with fatigue, fevers, and chills as the most common adverse events. No dose-limiting toxicities occurred. Confirmed objective response rate was 62%, with a complete response rate of 33% per immune-related response criteria. Patients who responded to combination therapy had increased CD8⁺ T cells, elevated PD-L1 protein expression, as well as IFN-γ gene expression on several cell subsets in tumors after talimogene laherparepvec treatment. Response to combination therapy did not appear to be associated with baseline CD8⁺ T cell infiltration or baseline IFN-γ signature. These findings suggest that oncolytic virotherapy may improve the efficacy of anti-PD-1 therapy by changing the tumor microenvironment. VIDEO ABSTRACT.

Oncolytic immunotherapy: unlocking the potential of viruses to help target cancer

Oncolytic immunotherapy is a research area of cancer immunotherapy investigating the use of modified viruses to target cancer cells. A variety of different viral backbones (e.g., adenovirus, reovirus) with a diverse range of genetic modifications are currently being investigated for the treatment of a variety of cancers. The oncolytic virus that has advanced the furthest in clinical development is talimogene laherparepvec, a recombinant HSV-1 virus expressing granulocyte-macrophage colony-stimulating factor (GM-CSF). In a phase 3 study in patients with unresectable metastatic melanoma, intralesional talimogene laherparepvec treatment resulted in a higher durable response rate compared with subcutaneous GM-CSF treatment (16.3 versus 2.1%; P < 0.001). Notably, responses were observed at uninjected lesions including visceral lesions, indicating a systemic antitumor response had occurred. Studies evaluating combination treatments involving oncolytic viruses and immunologic agents are ongoing. This review focuses on the mechanisms of action for oncolytic viruses and highlights select agents and combinations currently in development.

Talimogene Laherparepvec: An Oncolytic Virus Therapy for Melanoma

OBJECTIVE

To review the efficacy and safety of talimogene laherparepvec (T-VEC) as well as its pharmacology, pharmacokinetics, drug-drug interactions, handling procedures, cost considerations, and place in therapy.

DATA SOURCES

Searches of PubMed (1966 to February 2017) and Cochrane Library (1999 to February 2017) were conducted using the terms talimogene laherparepvec, T-VEC, OncoVEX, immunotherapy, melanoma, and oncolytic virus. Additional information was determined from bibliographies, manufacturer product labeling and website, meeting abstracts, Food and Drug Administration website, and clinicaltrials.gov.

STUDY SELECTION AND DATA EXTRACTION

A total of 79 English-language publications were identified. Articles that assessed T-VEC's pharmacokinetics, pharmacodynamics, mechanism, dosing, safety, and efficacy were included as well as narrative reviews that provided practical information.

DATA SYNTHESIS

Clinical trials have confirmed the safety and efficacy of T-VEC as monotherapy for the treatment of advanced melanoma, with an overall response rate (ORR) of 26%. Relative to granulocyte-macrophage colony-stimulating factor, T-VEC significantly increased durable response rate (DRR; 16.3% vs 2.1%, P < 0.001); however, median overall survival was not improved (23.3 vs 18.9 months, P = 0.051). Phase 1b trials have combined T-VEC and immunotherapies with promising results. T-VEC's adverse effects are generally considered mild to moderate in severity.

CONCLUSION

T-VEC is the first approved oncolytic virus for local treatment of unresectable cutaneous, subcutaneous, and nodal lesions in melanoma recurrent after initial surgery. T-VEC improves ORR and DRR as a single agent, shows promise in combination therapy, and is well tolerated. Ongoing trials will determine if T-VEC has a role in early treatment or in combination therapy for melanoma or other malignancies.

Spotlight on talimogene laherparepvec for the treatment of melanoma lesions in the skin and lymph nodes

On October 27, 2015, talimogene laherparepvec (T-VEC), a first in class intralesional oncolytic virotherapy, was granted the US Food and Drug Administration approval for the treatment of melanoma in the skin and lymph nodes. Its approval has added yet another therapeutic option to the growing list of effective therapies for melanoma. Though the Phase III OPTiM trial has demonstrated its efficacy as a single agent, the target patient population remains narrow. With numerous effective and tolerable treatments available for unresectable and metastatic melanoma, intralesional therapies such as T-VEC are still finding their niche. T-VEC is now widely accepted as option for treatment; however, its combination with various other agents in an effort to expand its use and synergize with other interventions is still being explored. This article will review the pre-clinical and clinical work that eventually led to the Food and Drug Administration approval of this first-in-class agent, as well as address concerns about clinical application and ongoing research.