Jonathan S. Zager

Talimogene Laherparepvec Improves Durable Response Rate in Patients With Advanced Melanoma

PURPOSE Talimogene laherparepvec (T-VEC) is a herpes simplex virus type 1-derived oncolytic immunotherapy designed to selectively replicate within tumors and produce granulocyte macrophage colony-stimulating factor (GM-CSF) to enhance systemic antitumor immune responses. T-VEC was compared with GM-CSF in patients with unresected stage IIIB to IV melanoma in a randomized open-label phase III trial. PATIENTS AND METHODS Patients with injectable melanoma that was not surgically resectable were randomly assigned at a two-to-one ratio to intralesional T-VEC or subcutaneous GM-CSF. The primary end point was durable response rate (DRR; objective response lasting continuously ≥ 6 months) per independent assessment. Key secondary end points included overall survival (OS) and overall response rate. RESULTS Among 436 patients randomly assigned, DRR was significantly higher with T-VEC (16.3%; 95% CI, 12.1% to 20.5%) than GM-CSF (2.1%; 95% CI, 0% to 4.5%]; odds ratio, 8.9; P < .001). Overall response rate was also higher in the T-VEC arm (26.4%; 95% CI, 21.4% to 31.5% v 5.7%; 95% CI, 1.9% to 9.5%). Median OS was 23.3 months (95% CI, 19.5 to 29.6 months) with T-VEC and 18.9 months (95% CI, 16.0 to 23.7 months) with GM-CSF (hazard ratio, 0.79; 95% CI, 0.62 to 1.00; P = .051). T-VEC efficacy was most pronounced in patients with stage IIIB, IIIC, or IVM1a disease and in patients with treatment-naive disease. The most common adverse events (AEs) with T-VEC were fatigue, chills, and pyrexia. The only grade 3 or 4 AE occurring in ≥ 2% of T-VEC-treated patients was cellulitis (2.1%). No fatal treatment-related AEs occurred. CONCLUSION T-VEC is the first oncolytic immunotherapy to demonstrate therapeutic benefit against melanoma in a phase III clinical trial. T-VEC was well tolerated and resulted in a higher DRR (P < .001) and longer median OS (P = .051), particularly in untreated patients or those with stage IIIB, IIIC, or IVM1a disease. T-VEC represents a novel potential therapy for patients with metastatic melanoma.

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma

BACKGROUND Sentinel‐lymph‐node biopsy is associated with increased melanoma‐specific survival (i.e., survival until death from melanoma) among patients with node‐positive intermediate‐thickness melanomas (1.2 to 3.5 mm). The value of completion lymph‐node dissection for patients with sentinel‐node metastases is not clear. METHODS In an international trial, we randomly assigned patients with sentinel‐node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph‐node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma‐specific survival. Secondary end points included disease‐free survival and the cumulative rate of nonsentinel‐node metastasis. RESULTS Immediate completion lymph‐node dissection was not associated with increased melanoma‐specific survival among 1934 patients with data that could be evaluated in an intention‐to‐treat analysis or among 1755 patients in the per‐protocol analysis. In the per‐protocol analysis, the mean (±SE) 3‐year rate of melanoma‐specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log‐rank test) at a median follow‐up of 43 months. The rate of disease‐free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log‐rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log‐rank test); these results must be interpreted with caution. Nonsentinel‐node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group. CONCLUSIONS Immediate completion lymph‐node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma‐specific survival among patients with melanoma and sentinel‐node metastases. (Funded by the National Cancer Institute and others; MSLT‐II ClinicalTrials.gov number, NCT00297895.)

Routine Omission of Sentinel Lymph Node Biopsy for Merkel Cell Carcinoma ≤ 1 cm Is Not Justified

TO THE EDITOR: Stokes et al recently reported a retrospective review of resected primary Merkel cell carcinoma (MCC) utilizing the Department of Veterans’ Affairs national health care database. The authors report 213 patients who had a resection of their primary MCC as well as an assessment of the regional lymph nodes by either sentinel lymph node biopsy (SNB) or complete lymphadenectomy (CLD). The patients were stratified into three groups based on the diameter of the primary tumor. The authors report that in the subgroup of 54 patients whose tumor diameter was 1 cm, only two patients had evidence of gross regional metastasis at presentation. None of the remaining 52 patients had nodal disease diagnosed by either SNB or elective CLD, although no data are presented to indicate who may have failed in the draining regional nodal basin at risk during the follow-up period. The authors conclude that regional lymph node assessment can be “reasonably and safely omitted” in patients who present with MCC 1 cm in diameter and without palpable disease. However, the routine omission of SNB in patients with MCC 1 cm diameter may not be justified based on the evidence presented in the report. Caution must be taken when utilizing national databases from multiple institutions, especially when attempting to characterize rare and diagnostically challenging malignancies such as MCC. In the methods section, the authors fail to report the precise manner in which the pathologic diagnosis of MCC was rendered in the primary tumor and whether this was standardized among all the various Veterans’ Affairs medical centers that contributed data toward this retrospective review. Without the use of appropriate immunostains, it is possible non-MCC cases were erroneously included in the study, which could potentially account for the relatively low recurrence rate of this study when compared with other reports. In addition, there is inherent difficulty and subjectivity in assessing tumor diameter, and precisely how this critical parameter was established was not mentioned by the authors (probably because it was impossible to determine in a retrospective database review). The authors also report the use of either SNB or elective CLD when staging clinically negative regional lymph nodes, but they failed to state the frequency of each modality. In addition, they do not elucidate the details of the pathologic examination of the nodal specimens. Specifically, elective CLD may not have been subjected to the thorough analysis to which SLN are typically subjected, with serial sectioning and immunohistochemistry. This could potentially lead to a higher false negative rate. The authors do report a 17% overall recurrence rate in the cohort of MCC with diameters 1 cm. However, the specific situations that led to recurrence are not enumerated: how many of these patients failed in the regional nodal basin as a false negative SNB? How many demonstrated regional nodal disease as the first site of recurrence in those patients previously treated without any nodal staging? How many failed in the regional nodes after CLD? These statistics would be important to note before concluding that small diameter MMCs routinely do not metastasize to lymph nodes. In addition, the 17% recurrence rate could omit cases that were missed due to the difficulty in establishing a diagnosis of microscopic metastasis in a complete lymph node dissection specimen. It should also be noted that it is difficult to interpret the significance of the recurrence rate, because the length of follow-up for any of the individual subgroups was not reported. In an attempt to validate the results reported in this study, we recently reviewed our single institution’s experience regarding the use of SNB to diagnosis microscopic regional lymph node metastasis in MCC with diameters 1 cm. In contrast to the findings of this study, we found evidence of clinically occult regional lymph node metastasis in five of 12 cases (42%). This marked difference may be due to the exclusive use of SNB rather than elective CLD as well as our routine application of appropriate immunostaining of the sentinel lymph node. Our findings from a large referral center with a relatively high volume of patients with MCC refute the premise that it is safe to omit SNB in 1 cm diameter MCC based on an anticipated low yield of positive sentinel nodes. Changes in “standard” surgical practice in a rare disease such as MCC should require strong evidence, preferably from prospective trials, before they are adopted.

Clinicopathologic Predictors of Sentinel Lymph Node Metastasis in Thin Melanoma

PURPOSE Indications for sentinel lymph node biopsy (SLNB) for thin melanoma are continually evolving. We present a large multi-institutional study to determine factors predictive of sentinel lymph node (SLN) metastasis in thin melanoma. PATIENTS AND METHODS Retrospective review of the Sentinel Lymph Node Working Group database from 1994 to 2012 identified 1,250 patients who had an SLNB and thin melanomas (≤ 1 mm). Clinicopathologic characteristics were correlated with SLN status and outcome. RESULTS SLN metastases were detected in 65 (5.2%) of 1,250 patients. On univariable analysis, rates of Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, ulceration, and absence of regression differed significantly between positive and negative SLN groups (all P < .05). These four variables and mitotic rate were used in multivariable analysis, which demonstrated that Breslow thickness ≥ 0.75 mm (P = .03), Clark level ≥ IV (P = .05), and ulceration (P = .01) significantly predicted SLN metastasis with 6.3%, 7.0%, and 11.6% of the patients with these respective characteristics having SLN disease. Melanomas < 0.75 mm had positive SLN rates of < 5% regardless of Clark level and ulceration status. Median follow-up was 2.6 years. Melanoma-specific survival was significantly worse for patients with positive versus negative SLNs (P = .001). CONCLUSION Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, and ulceration significantly predict SLN disease in thin melanoma. Most SLN metastases (86.2%) occur in melanomas ≥ 0.75 mm, with 6.3% of these patients having SLN disease, whereas in melanomas < 0.75 mm, SLN metastasis rates are < 5%. By using a 5% metastasis risk threshold, SLNB is indicated for melanomas ≥ 0.75 mm, but further study is needed to define indications for SLNB in melanomas < 0.75 mm.

Effects of Preexisting Immunity on the Response to Herpes Simplex-Based Oncolytic Viral Therapy

Herpes simplex viruses (HSV) type 1 are the basis of a number of anticancer strategies that have proven efficacious in animal models. They are natural human pathogens and the majority of adults have anti-HSV immunity. The current study examined the effect of preexisting immunity on the response to herpes-based oncolytic viral treatment of hepatic metastatic cancer in a murine model designed to simulate a clinical approach likely to be utilized for nonneurological tumors. Specifically, the anticancer effects of NV1020 or G207, two multimutated HSV-1 oncolytic viruses, were tested in immunocompetent mice previously immunized with a wild-type herpes simplex type 1 virus. Mice were documented to have humoral as well as cell-mediated immunity to HSV-1. Tumor response to oncolytic therapy was not measurably abrogated by immunity to HSV at the doses tested. The influence of route of viral administration was also tested in models of regional hepatic arterial and intravenous therapy. Route of viral administration influenced efficacy, as virus delivered intravenously produced some detectable attenuation while hepatic arterial therapy remained unaffected. These results demonstrate that when given at appropriate doses and in reasonable proximity to tumor targets, HSV-based oncolytic therapy can still be expected to be effective treatment for patients with hepatic malignancies.

Combination of External Beam Radiotherapy (EBRT) With Intratumoral Injection of Dendritic Cells as Neo-Adjuvant Treatment of High-Risk Soft Tissue Sarcoma Patients

PURPOSE The goal of this study was to determine the effect of combination of intratumoral administration of dendritic cells (DC) and fractionated external beam radiation (EBRT) on tumor-specific immune responses in patients with soft-tissue sarcoma (STS). METHODS AND MATERIAL Seventeen patients with large (>5 cm) high-grade STS were enrolled in the study. They were treated in the neoadjuvant setting with 5,040 cGy of EBRT, split into 28 fractions and delivered 5 days per week, combined with intratumoral injection of 10(7) DCs followed by complete resection. DCs were injected on the second, third, and fourth Friday of the treatment cycle. Clinical evaluation and immunological assessments were performed. RESULTS The treatment was well tolerated. No patient had tumor-specific immune responses before combined EBRT/DC therapy; 9 patients (52.9%) developed tumor-specific immune responses, which lasted from 11 to 42 weeks. Twelve of 17 patients (70.6%) were progression free after 1 year. Treatment caused a dramatic accumulation of T cells in the tumor. The presence of CD4(+) T cells in the tumor positively correlated with tumor-specific immune responses that developed following combined therapy. Accumulation of myeloid-derived suppressor cells but not regulatory T cells negatively correlated with the development of tumor-specific immune responses. Experiments with (111)In labeled DCs demonstrated that these antigen presenting cells need at least 48 h to start migrating from tumor site. CONCLUSIONS Combination of intratumoral DC administration with EBRT was safe and resulted in induction of antitumor immune responses. This suggests that this therapy is promising and needs further testing in clinical trials design to assess clinical efficacy.

Multimodality management of desmoid tumors: how important is a negative surgical margin?

Desmoid tumors are rare, locally invasive mesenchymal tumors without metastatic potential. Their clinical behavior is heterogeneous and characteristically unpredictable; outcomes are influenced by anatomic location, proximity to vital organs, association with familial adenomatous polyposis. Surgery is the main treatment modality, but the significance of positive resection margins remains controversial since they may not increase the risk of recurrence: in this setting re‐resection, adjuvant radiation or close clinical follow‐up could all be appropriate options. We reviewed the current evidence for multimodality therapy of desmoids, with a focus on the importance of resection margins, and present our own algorithm for treatment. J. Surg. Oncol. 2008;98:594–602.

Efficacy of adoptive cell transfer of tumor-infiltrating lymphocytes after lymphopenia induction for metastatic melanoma.

A single-institution pilot clinical trial was performed combining nonmyeloablative chemotherapy and the adoptive transfer of tumor-infiltrating lymphocytes with interleukin-2 in patients with metastatic melanoma. Nineteen patients were enrolled with 13 patients (68%) successfully completing treatment. An overall response rate (partial and complete responses) of 26% by intention to treat was achieved with a median follow-up time of 10 months. Of the 13 treated patients, there were 2 complete responses and 3 partial responses (38% response rate among treated patients), along with 4 patients with stable disease ranging from 2+ to 24+months. Three of the 4 patients with stable disease have had disease control without additional therapy, including one at 24+ months. Adoptive therapy with infiltrating lymphocytes is labor intensive but feasible and has a high response rate in treated patients.

Interleukin 12 Secretion Enhances Antitumor Efficacy of Oncolytic Herpes Simplex Viral Therapy for Colorectal Cancer

ObjectiveTo assess the strategy of combining oncolytic herpes simplex virus (HSV) therapy with immunomodulatory therapy as treatment for experimental colon cancer. The oncolytic HSV recombinant NV1023 and the interleukin 12 (IL-12)-secreting oncolytic NV1042 virus were evaluated in vitro and in vivo with respect to antitumor efficacy. Summary Background DataGenetically engineered, replication-conditional, attenuated HSVs have shown oncolytic activity against a wide variety of solid malignancies. Other strategies for treating cancer have involved immunomodulation and cytokine gene transfer using viral vectors. This study has combined both of these strategies by inserting the murine IL-12 gene into a replication-competent HSV. This approach allows oncolytic therapy to replicate selectively within and lyse tumor cells while providing the host immune system with the cytokine stimulus necessary to recruit and activate inflammatory cells needed to enhance the antitumor effect. MethodsNV1023 is a multimutant HSV based on the wild-type HSV-1 F strain. NV1042 was created by insertion of the mIL-12 gene into NV1023. Cytotoxicity and viral proliferation of both NV1023 and NV1042 within murine CT26 colorectal cancer cells were first shown. Cells infected with NV1042 were then shown to produce significant levels of IL-12. Using an experimental flank model of colon cancer, mice were treated with both high and low doses of NV1023 or NV1042 and were followed up for both cure and reduction in tumor burden. ResultsBoth viruses could replicate within and kill CT26 cells in vitro, with 100% cytotoxicity achieved after infection by either virus. Only NV1042 could produce mIL-12. Therapy using high viral doses to treat animals in vivo showed equal efficacy between NV1023 and NV1042, with five of seven cures for each virus. When viral doses were lowered, only the cytokine-producing NV1042 virus could reduce tumor burden and cure animals of their disease. ConclusionsBoth NV1023 and NV1042 have the oncolytic potential to kill colon cancer cells at higher doses. Cytokine production by NV1042 may allow lower doses of viral therapy to be used without losing antitumor efficacy. The combination of oncolytic viral therapy and immunomodulatory strategies should be further investigated as treatment for colon cancer.

Sentinel Lymph Node Biopsy for Melanoma: Indications and Rationale

BACKGROUND The disease status of regional lymph nodes is the most important prognostic indicator for patients with melanoma. Sentinel lymph node biopsy (SLNB) was developed as a technique to surgically assess the regional lymph nodes and spare node-negative patients unnecessary and potentially morbid complete lymphadenectomies. METHODS We reviewed the literature on SLNB for cutaneous melanoma to provide insight into the rationale for the current widespread use of SLNB. RESULTS Multiple studies show that the status of the SLN is an important prognostic indicator. Those with positive SLNs have significantly decreased disease-free and melanoma-specific survival compared with those who have negative SLNs. In the Multicenter Selective Lymphadenectomy Trial I (MSLT-I), in which patients with intermediate-thickness melanoma were randomized to SLNB (and immediate completion lymphadenectomy if the SLN was positive) vs observation (and a lymphadenectomy only after presenting with clinically evident recurrence), the 5-year survival rate was 72.3% for patients with positive sentinel nodes and 90.2% for those with negative sentinel nodes (P < .001). Although overall survival was not increased in patients who underwent SLNB compared with those who were randomized to observation, patients who underwent SLNB had a significantly increased 5-year disease-free survival rate compared with those who underwent observation alone (78.3% in the biopsy group and 73.1% in the observation group; P = .009). For those with nodal metastases, patients who underwent SLNB and immediate lymphadenectomy had an increased overall 5-year survival rate compared with those who had lymphadenectomy only after presenting with clinically evident disease (72.3% vs 52.4%; P = .004). Moreover, other studies show that for patients with thin melanomas <or= 1.0 mm, the overall survival rate is significantly worse for those with positive SLNs compared to those with negative SLNs. For thin melanomas, Breslow depth >or= 0.76 mm and increased mitotic rate have been shown to be associated with an increased incidence of SLN metastases. CONCLUSIONS SLNB provides important prognostic and staging data with minimal morbidity and can be used to identify regional node-negative patients who would not benefit from a complete nodal dissection. In our opinion, SLNB should be performed on most patients (with acceptable surgical and anesthesia risk) who have melanomas with a Breslow depth >or= 0.76 mm.