Evaluation of interferon alpha-2B and thalidomide in patients with disseminated malignant melanoma, phase 2, SWOG 0026

Angiogenesis and progression in human melanoma

In tumor growth, angiogenesis, the process of new-formation of blood vessels from pre-existing ones, is uncontrolled and unlimited in time. The vascular phase is characterized by the new-formation of vascular channels that enhances tumor cell proliferation, local invasion and hematogenous metastasis. Human malignant melanoma is a highly metastatic tumor with poor prognosis, and high resistance to treatment. Parallel with progression, melanoma acquires a rich vascular network, whereas an increasing number of tumor cells express the laminin receptor, which enables their adhesion to the vascular wall, favouring tumor cell extravasation and metastases. Melanoma neovascularization has been correlated with poor prognosis, overall survival, ulceration and increased rate of relapse. Secretion of various angiogenic cytokines, i.e. VEGF-A, FGF-2, PGF-1 and -2, IL-8, and TGF-1 by melanoma cells promote the angiogenic switch and has been correlated to transition from the radial to the vertical growth phase, and to the metastatic phase. Moreover, melanoma cells overexpress alphavbeta3, alphavbeta5, alpha2beta1 and alpha5beta1 integrins and release, together with stromal cells, higher amount of metalloproteases that increasing their invasive potential and angiogenesis. Basing on these observations, different molecular targets of antiangiogenic molecules has be recognized and various antiangiogenic agents are currently in preclinical and clinical trials for melanoma.

Angiogenesis and melanoma

Angiogenesis occurs in pathological conditions, such as tumors, where a specific critical point in tumor progression is the transition from the avascular to the vascular phase. Tumor angiogenesis depends mainly on the release by neoplastic cells of growth factors specific for endothelial cells, which are able to stimulate the growth of the host's blood vessels. This article summarizes the literature concerning the relationship between angiogenesis and human melanoma progression. The recent applications of antiangiogenic agents which interfere with melanoma progression are also described.

A phase 1 study of granulocyte macrophage colony-stimulating factor (sargramostim) and escalating doses of thalidomide in patients with high-risk malignant melanoma

This phase 1 study evaluated the safety and tolerability of adjuvant treatment with subcutaneous granulocyte macrophage colony-stimulating factor (GM-CSF) administered in combination with escalating doses of thalidomide in patients with surgically resected stage II (T4), III, or IV melanoma at high risk for recurrence. Adjuvant treatment included GM-CSF 125 microg/m2 subcutaneously for 14 days and thalidomide at an initial dose of 50 mg/d, escalated in cohorts of 3 to 6 patients each to a maximum of 400 mg/d followed by 14 days of rest. Treatment was continued for up to 1 year in the absence of disease progression. Of 19 patients treated, the most common toxicities were grade 1/2 constipation (68%), fatigue (58%), neuropathy (42%), bone and joint pain (37%), and dyspnea, dizziness, injection site skin reaction, and somnolence (32% each). Thrombotic events in 3 of 19 patients (16%), including 1 treatment-related death, were the most serious adverse events and were thought to be due to thalidomide. With a median follow-up of 945 days (2.6 y), 8 (42%) patients were alive, including 1 with disease and 7 without evidence of disease. GM-CSF plus thalidomide as adjuvant therapy for patients with resected high-risk melanoma was associated with a high incidence of thrombotic events. Because life-threatening events are unacceptable in the adjuvant setting, up-front antithrombotic prophylaxis will be necessary for further evaluation of GM-CSF plus thalidomide as a viable regimen in this patient group.

Therapeutic potential of mesenchymal stem cells producing interferon-alpha in a mouse melanoma lung metastasis model

Adult stem cells represent a potential source for cell-based therapy of cancer. The present study evaluated the potential of bone marrow-derived mesenchymal stem cells (MSC), genetically modified to express interferon (IFN)-alpha, for the treatment of lung metastasis in an immunocompetent mouse model of metastatic melanoma. A recombinant adeno-associated virus (rAAV) 6 vector encoding IFN-alpha was used to transduce mouse bone marrow-derived MSC ex vivo. Expression and bioactivity of the transgenic protein from rAAV-transduced MSC were confirmed prior to in vivo studies. A lung metastasis model of melanoma was developed by i.v. injection of B16F10 cells into 8-week-old C57BL/6 mice. Ten days later, MSC transduced with rAAV-IFN-alpha or green fluorescent protein were intravenously injected. One cohort of mice was sacrificed to determine the effects of the therapy at an earlier time point, and another cohort was observed for long-term survival. Results indicated that systemic administration of MSC producing IFN-alpha reduced the growth of B16F10 melanoma cells and significantly prolonged survival. Immunohistochemistry analysis of the tumors from MSC-IFN-alpha-treated animals indicated an increase in apoptosis and a decrease in proliferation and blood vasculature. These data demonstrate the potential of adult MSC constitutively producing IFN-alpha to reduce the growth of lung metastasis in melanoma.