Local Tumor Treatment in Combination with Systemic Ipilimumab Immunotherapy Prolongs Overall Survival in Patients with Advanced Malignant Melanoma

Immune checkpoint inhibition with ipilimumab has revolutionized cancer immunotherapy and significantly improved outcomes of patients with advanced malignant melanoma. Local peripheral treatments (LPT), such as radiotherapy or electrochemotherapy, have been shown to modulate systemic immune responses, and preliminary data have raised the hypothesis that the combination of LPT with systemic immune checkpoint blockade might be beneficial. Clinical data from 127 consecutively treated melanoma patients at four cancer centers in Germany and Switzerland were analyzed. Patients received either ipilimumab (n = 82) or ipilimumab and additional LPT (n = 45) if indicated for local tumor control. The addition of LPT to ipilimumab significantly prolonged overall survival (OS; median OS 93 vs. 42 weeks, unadjusted HR, 0.46; P = 0.0028). Adverse immune-related events were not increased by the combination treatment, and LPT-induced local toxicities were in most cases mild. In a multivariable Cox regression analysis, we show that the effect of added LPT on OS remained statistically significant after adjusting for BRAF status, tumor stage, tumor burden, and central nervous system metastases (adjusted HR, 0.56; 95% confidence interval, 0.31-1.01, P = 0.05). Our data suggest that the addition of LPT to ipilimumab is safe and effective in patients with metastatic melanoma irrespective of clinical disease characteristics and known risk factors. Induction of antitumor immune responses is most likely the underlying mechanism and warrants prospective validation. Cancer Immunol Res; 4(9); 744-54. ©2016 AACR.

Electrochemotherapy in advanced skin tumors and cutaneous metastases - a retrospective multicenter analysis

BACKGROUND AND OBJECTIVES

Once classic treatments such as chemotherapy or radiation therapy have been exhausted, only few therapeutic options remain for extensive skin tumors or cutaneous metastases. In such cases, electrochemotherapy may be considered as alternative therapy.

PATIENTS AND METHODS

In this retrospective study, clinical features, treatment response, and adverse effects were evaluated in 56 patients treated with electrochemotherapy at six German dermatology departments.

RESULTS

The mean age of the patient cohort (14 men, 42 women) was 69.3 years. Included were 20 patients with skin metastasis of advanced malignant melanoma, 13 patients with breast cancer metastases, 15 patients with primary squamous cell carcinoma of the skin or cutaneous metastases of other carcinoma types, and 8 patients with cutaneous lymphoma or sarcoma. The overall response rate was 44.6% (10.7% complete response; 33.9% partial response). By contrast, 31 (55.4%) patients did not respond (12.5% had stable disease; 42.9%, tumor progression). Patients with melanoma and cutaneous lymphoma or sarcoma responded significantly better than those with carcinoma. Roughly one quarter of patients showed an improvement in tumor-related exudation, fetor, and chronic bleeding.

CONCLUSION

Showing only few adverse effects, electrochemotherapy was effective in about one half of the patients with advanced tumors. Treatment response appears to depend on the tumor entity.

[Merkel cell carcinoma]

Merkel cell carcinoma is a rare aggressive malignant neuroendocrine skin tumor, which can metastasize to lymph nodes early and often shows local recurrence. The prognosis depends on tumor size and disease stage. The majority of recurrences appear during the first 2 years after the primary diagnosis. The 5-year survival rate for primary tumor < 2 cm is 66-75 % and for primary tumors > 2 cm is 50-60 %. With lymph node metastases the 5-year survival rate is 42-52 %, while with distant metastases it drops to 17-12 %. Extensive staging inclusive sentinel lymph node biopsy is essential to assess the risk for distant metastasis and to allow the best recommendations for therapy. After surgical treatment with adequate safety margin, subsequent adjuvant radiation therapy of the tumor region and lymphatic draining basin is recommended to reduce the risk of local recurrence and lymphatic spread.

Microtubule-depolymerizing agents used in antibody-drug conjugates induce antitumor immunity by stimulation of dendritic cells

Antibody-drug conjugates (ADC) are emerging as powerful treatment strategies with outstanding target-specificity and high therapeutic activity in patients with cancer. Brentuximab vedotin represents a first-in-class ADC directed against CD30(+) malignancies. We hypothesized that its sustained clinical responses could be related to the stimulation of an anticancer immune response. In this study, we demonstrate that the dolastatin family of microtubule inhibitors, from which the cytotoxic component of brentuximab vedotin is derived, comprises potent inducers of phenotypic and functional dendritic cell (DC) maturation. In addition to the direct cytotoxic effect on tumor cells, dolastatins efficiently promoted antigen uptake and migration of tumor-resident DCs to the tumor-draining lymph nodes. Exposure of murine and human DCs to dolastatins significantly increased their capacity to prime T cells. Underlining the requirement of an intact host immune system for the full therapeutic benefit of dolastatins, the antitumor effect was far less pronounced in immunocompromised mice. We observed substantial therapeutic synergies when combining dolastatins with tumor antigen-specific vaccination or blockade of the PD-1-PD-L1 and CTLA-4 coinhibitory pathways. Ultimately, treatment with ADCs using dolastatins induces DC homing and activates cellular antitumor immune responses in patients. Our data reveal a novel mechanism of action for dolastatins and provide a strong rationale for clinical treatment regimens combining dolastatin-based therapies, such as brentuximab vedotin, with immune-based therapies.

Comparison of high resolution melting analysis, pyrosequencing, next generation sequencing and immunohistochemistry to conventional Sanger sequencing for the detection of p.V600E and non-p.V600E BRAF mutations

Background

The approval of vemurafenib in the US 2011 and in Europe 2012 improved the therapy of not resectable or metastatic melanoma. Patients carrying a substitution of valine to glutamic acid at codon 600 (p.V600E) or a substitution of valine to leucine (p.V600K) in BRAF show complete or partial response. Therefore, the precise identification of the underlying somatic mutations is essential. Herein, we evaluate the sensitivity, specificity and feasibility of six different methods for the detection of BRAF mutations.

Methods

Samples harboring p.V600E mutations as well as rare mutations in BRAF exon 15 were compared to wildtype samples. DNA was extracted from formalin-fixed paraffin-embedded tissues by manual micro-dissection and automated extraction. BRAF mutational analysis was carried out by high resolution melting (HRM) analysis, pyrosequencing, allele specific PCR, next generation sequencing (NGS) and immunohistochemistry (IHC). All mutations were independently reassessed by Sanger sequencing. Due to the limited tumor tissue available different numbers of samples were analyzed with each method (82, 72, 60, 72, 49 and 82 respectively).

Results

There was no difference in sensitivity between the HRM analysis and Sanger sequencing (98%). All mutations down to 6.6% allele frequency could be detected with 100% specificity. In contrast, pyrosequencing detected 100% of the mutations down to 5% allele frequency but exhibited only 90% specificity. The allele specific PCR failed to detect 16.3% of the mutations eligible for therapy with vemurafenib. NGS could analyze 100% of the cases with 100% specificity but exhibited 97.5% sensitivity. IHC showed once cross-reactivity with p.V600R but was a good amendment to HRM.

Conclusion

Therefore, at present, a combination of HRM and IHC is recommended to increase sensitivity and specificity for routine diagnostic to fulfill the European requirements concerning vemurafenib therapy of melanoma patients.

Allogeneic stem cell transplantation in patients with aggressive primary cutaneous T-cell lymphoma - a case series of the ADF working group "cutaneous lymphomas"

BACKGROUND

Allogeneic stem cell transplantation (alloSCT) is a treatment option for primary cutaneous T-cell lymphomas that may induce long-lasting complete remissions. Little information is available on safety and efficacy.

PATIENTS AND METHODS

We retrospectively reviewed the data from patients with primary cutaneous T-cell lymphoma treated in the Departments of Dermatology of the Universities of Bochum, Mannheim and Cologne who received subsequent alloSCT between 2005 and 2012.

RESULTS

Nine patients with aggressive primary cutaneous T-cell-lymphoma received alloSCT. With a follow-up of 14 to 36 months after transplantation, 4 patients are alive and in complete remission. Two patients had recurrent disease post-transplantation, which was successfully treated with donor lymphocyte infusions. Non-relapse mortality was observed in three patients in advanced disease stages within six months after alloSCT. One patient showed only partial remission and died of disease after 32 months and one patient died 26 months after alloSCT with cause of death unknown.

CONCLUSIONS

This report documents the possible benefit of a graft-versus-lymphoma effect in primary cutaneous T-cell lymphoma, as has been observed for other T-cell malignancies and emphasizes that alloSCT warrants further studies in this setting.

Allogeneic stem cell transplantation versus conventional therapy for advanced primary cutaneous T-cell lymphoma

BACKGROUND

Primary cutaneous T-cell lymphomas (CTCL) belong to the group of non-Hodgkin lymphomas and usually run an indolent course. However, some patients progress to advanced tumour or leukaemic stages. To date, there is no cure for those cases. In the last few years, several publications reported durable responses in some patients following allogeneic stem cell transplantation (alloSCT). This is an update of a Cochrane review first published in 2011 and updated in 2013.

OBJECTIVES

To compare the efficacy and safety of conventional therapies with allogeneic stem cell transplantation in patients with advanced primary cutaneous T-cell lymphomas.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 1), MEDLINE (1950 to January 2013), Internet-databases of ongoing trials, conference proceedings of the American Society of Clinical Oncology (ASCO, 2009 to July 2013) and the American Society of Hematology (ASH, 2009 to July 2013). We also contacted members of the European Organisation for Research and Treatment of Cancer (EORTC) Cutaneous Lymphoma Task Force to check for ongoing study activities. We handsearched citations from identified trials and relevant review articles. In addition, we handsearched randomised controlled trials from the European Group for Blood and Marrow Transplantation (EBMT) and International Conference on Cutaneous T-cell Lymphoma, ASCO and ASH up to July 2013.

SELECTION CRITERIA

Trials eligible for inclusion were genetically randomised controlled trials (RCTs) comparing alloSCT plus conditioning therapy (regardless of agents) with conventional therapy as treatment for advanced CTCL.

DATA COLLECTION AND ANALYSIS

Two review authors would have extracted data from eligible studies and assessed their quality. The primary outcome measure was overall survival; secondary outcomes were time to progression, response rate, treatment-related mortality, adverse events and quality of life.

MAIN RESULTS

We did not identify any randomised controlled trials from the updated search in January 2013. In 2011, we found 2077 citations but none were relevant genetically or non-genetically randomised controlled trials. All 41 studies that were thought to be potentially suitable were excluded after full text screening for being non-randomised, not including CTCL or being review articles.

AUTHORS' CONCLUSIONS

We planned to report evidence from genetically or non-genetically randomised controlled trials comparing conventional therapy and allogeneic stem cell transplantation. However, we did not identify any randomised controlled trials addressing this question. Nevertheless, prospective genetically randomised controlled trials need to be initiated to evaluate the precise role of alloSCT in advanced CTCL.

(68)Ga-DotaTATE PET-CT followed by Peptide Receptor Radiotherapy in combination with capecitabine in two patients with Merkel Cell Carcinoma

Herein, we report about two Caucasian patients with the histopathological diagnosis of Merkel cell carcinoma suffering from extensive lymph node metastases. The extent of the disease was diagnosed by Ga-68-DotaTATE-PET-CT. Both patients had rapid disease progression, one of them despite a three months course of sunitinibe followed by four chemotherapy cycles of cisplatin and etoposide. Both patients were sent for peptide receptor radiotherapy with 90Y-DotaTATE or 177Lu-DotaTATE in combination with capecitabine. Additional external beam radiotherapy of the cervical and inguinal lymph nodes was given to the patient with progressive disease despite chemotherapy. Temporary partial response in both patients was achieved. Despite extensive therapeutic efforts, fatal outcome could not be prevented 10 and 14 months after first clinical symptoms.

Pentoxifylline inhibits the fibrogenic activity of pleural effusions and transforming growth factor-beta

Physiopathology of organ fibrosis is far from being completely understood, and the efficacy of the available therapeutic strategies is disappointing. We chose pleural disease for further studies and addressed the questions of which cytokines are relevant in pleural fibrosis and which drugs might interrupt its development. We screened pleural effusions for mediators thought to interfere with fibrogenesis (transforming growth factor-β (TGF-β), tumour necrosis factor α (TNFα), soluble TNF-receptor p55 (sTNF-R)) and correlated the results with patient clinical outcome in terms of extent of pleural thickenings. We found pleural thickenings correlated with TGF-β (p < 0.005) whereas no correlations could be observed with TNFα and sTNF-R. Further, we were interested in finding out how TGF-β effects on fibroblast growth could be modulated. We found that pentoxifylline is able to inhibit both fibroblast proliferation and collagen synthesis independently of the stimulus. We conclude that, judging from in vitro studies, pentoxifylline might offer a new approach in the therapy of pleural as well as pulmonary fibrosis.

Regression of metastatic melanoma in a patient by antibody targeting of cancer stem cells

Current therapeutic regimens attempt to eliminate all malignant cells of a melanoma lesion. Pre-clinical data, however, indicate that melanoma is maintained by a minor subset of cancer cells, which are characterized by CD20 expression. We attempted to eliminate those cells in a progressing, chemotherapy-refractory metastatic melanoma patient by lesional injections of the anti-CD20 therapeutic antibody rituximab and concomitant dacarbazine treatment, which was ineffective as monotherapy. Although the frequency of CD20⁺ melanoma cells within the tumor lesions was initially about 2% and the bulk of tumor cells did not express CD20, rituximab treatment produced lasting remission accompanied by a decline of the melanoma serum marker S-100 to physiological levels. Detailed in-depth-analyses revealed a switch of serum cytokines from a T helper-2 to a pro-inflammatory T helper-1 cell profile. Apart from B cell elimination and decline in gammaglobulin levels, no grade 3/4 toxicity related to treatment was observed. Data provide the first clinical evidence that targeting the minor subset of CD20⁺ “melanoma sustaining cells” produces regression of chemotherapy-refractory melanoma and highlight the potency of selective cancer cell targeting in the treatment of melanoma.