Seth M. Cohen

Characterization of CD4+CD25+ Regulatory T Cells in Patients Treated With High-Dose Interleukin-2 for Metastatic Melanoma or Renal Cell Carcinoma

PURPOSE To characterize the number and functional status of CD4+CD25+ regulatory T cells (Tregs) in patients with metastatic melanoma (MM) and renal cell carcinoma (RCC) treated with high-dose bolus interleukin-2 (IL-2). PATIENTS AND METHODS Patients with MM or RCC treated with high-dose bolus IL-2 (600,000 IU/kg every 8 hours) at a single center provided pre- and post-treatment whole blood specimens. Peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation, separated into cellular subsets, and analyzed by flow cytometry or used for in vitro proliferation assays. RESULTS Between September 2003 and July 2005 57 patients were enrolled in the study with 48 patients available for analysis (45 MM, 12 RCC). Tregs were defined as CD4+CD25(hi) T cells, and this subset was significantly elevated in the cancer patients compared with normal donors (7.75% v 2.24%). The CD4(+)CD25(hi) T-cell pool in the patients constitutively expressed intracellular FoxP3, CTLA-4, and produced high amounts of IL-10. The Tregs were CCR7+ with 50% representing naïve and 50% central-memory T cells. The cells were functionally suppressive in mixed in vitro proliferation assays. Following IL-2 administration, the number and frequency of Tregs increased in patients with progressive disease but returned to normal levels in patients with objective clinical responses. CONCLUSION The number of Tregs, defined as CD4+CD25(hi) T cells is increased in patients with MM and RCC. High-dose IL-2 resulted in a significant decrease of Tregs in those patients achieving an objective clinical response to IL-2 therapy.

Targeting the local tumor microenvironment with vaccinia virus expressing B7.1 for the treatment of melanoma

Immunotherapy for the treatment of metastatic melanoma remains a major clinical challenge. The melanoma microenvironment may lead to local T cell tolerance in part through downregulation of costimulatory molecules, such as B7.1 (CD80). We report the results from the first clinical trial, to our knowledge, using a recombinant vaccinia virus expressing B7.1 (rV-B7.1) for monthly intralesional vaccination of accessible melanoma lesions. A standard 2-dose-escalation phase I clinical trial was conducted with 12 patients. The approach was well tolerated with only low-grade fever, myalgias, and fatigue reported and 2 patients experiencing vitiligo. An objective partial response was observed in 1 patient and disease stabilization in 2 patients, 1 of whom is alive without disease 59 months following vaccination. All patients demonstrated an increase in postvaccination antibody and T cell responses against vaccinia virus. Systemic immunity was tested in HLA-A*0201 patients who demonstrated an increased frequency of gp100 and T cells specific to melanoma antigen recognized by T cells 1 (MART-1), also known as Melan-A, by ELISPOT assay following local rV-B7.1 vaccination. Local immunity was evaluated by quantitative real-time RT-PCR, which suggested that tumor regression was associated with increased expression of CD8 and IFN-gamma. The local delivery of vaccinia virus expressing B7.1 was well tolerated and represents an innovative strategy for altering the local tumor microenvironment in patients with melanoma.

Phase 2 trial of afatinib, an ErbB family blocker, in solid tumors genetically screened for target activation

The efficacy of afatinib, an irreversible ErbB Family Blocker, was evaluated in patients who had 1 of 4 categories of solid tumors with epidermal growth factor receptor/human epidermal growth factor receptor 2 (EGFR/HER2) gene amplification or EGFR‐activating mutations.

Her-2 targeting in uterine papillary serous carcinoma.

► A case of metastatic uterine papillary serous cancer with Her-2 gene amplification. ► Was treated with a Her-2 targeted agent and achieved durable remission. ► Her-2 targeting should be considered alone or in combination with chemotherapy.

Combination Cytokine Therapy

Cytokines represent a diverse group of small, soluble polypeptides that are involved in regulating a wide range of physiologic processes, including inflammation, tissue repair, and immunity. The expanding role of cytokines in these processes and the identification of over 100 putative cytokine family members have made it difficult to easily classify cytokines based on structure or function. In addition, many cytokines exhibit a variety of biologic activities and these effects may be dependent on the concentration, timing, and duration of target cell exposure to a given cytokine, as well as the influence of other cytokine and growth factors in the local microenvironment. In fact, much of the early characterization of cytokines was based on simple in vitro experiments, which have failed to accurately predict the activity of cytokines in vivo. More recent investigation using targeted knockout mice and analysis of cytokine signaling pathways is leading to new insights into the biology of many cytokines. This is perhaps best exemplified by interleukin-2 (IL-2), originally described as a T-cell growth factor and defined by its ability to induce T-cell proliferation in vitro. Such ex vivo studies predicted that IL-2 would function to promote cellular immunity through expansion of naive T-cell populations in vivo. The availability of IL-2 and IL-2 receptor knockout mice, however, demonstrated that in the absence of IL-2 signaling T-cell proliferation was increased, significant lymphadenopathy occurred, and animals succumb to aggressive autoimmune disease. This unexpected result suggests that IL-2 may actually function in vivo, not as a T-cell stimulant, but rather as a regulatory cytokine maintaining peripheral tolerance through balancing effector and regulatory T-cell pools (1).

The Risk of Fracture in Patients Undergoing Androgen Deprivation May Be Overstated: Analysis of an Unselected Cohort of Patients

Objective: In this study we examined the prevalence of fracture among men undergoing ADT for prostate cancer to determine if the fracture risk was increased among this population. Background: Androgen deprivation therapy (ADT) is a therapeutic approach for men with various prostate cancer disease states. Treatment-related side effects of ADT include rapid bone loss. Previous studies have found that the bone loss related to ADT leads to the development of fractures. Methods: This is a retrospective cohort study of patients treated with ADT in a radiation oncology and medical oncology practice at an urban academic medical center from 2005 to 2010. Patients with evidence of bone metastases responsive to ADT were included. Those with androgen-independent prostate cancer were excluded. Results: One hundred thirty patients met the inclusion criteria and among them only three fractures occurred during 373 person-years of follow-up. The fracture-free survival (FFS) rate at three years for all was 97.7%. Excluding fractures occurring within six months of ADT initiation, the FFS rate was 100% at three years. No significant difference was demonstrated in those screened with a pretreatment dual-emission X-ray absorptiometry (DEXA) scan; there was no relationship between the number of ADT cycles, recovery of testosterone to normal, or total time on ADT. Older patients, surprisingly, had a lower risk (p = 0.054). Patients with normal bone mineral density (BMD) had an FFS rate of 93.8% at three years, osteopenic patients had 94.7%, and patients with osteoporosis and hormone-responsive metastases had 100%. Conclusion: The prevalence of fracture among this group is significantly less than what has previously been reported for men receiving ADT, potentially suggesting an overstatement of risk in the literature to date. Further prospective study with a larger sample size is needed.

Analysis of the risk of fracture in an unselected cohort of patients undergoing androgen deprivation.

193 Background: Androgen deprivation therapy (ADT) is a therapeutic approach for men with various prostate cancer disease states. Treatment related side effects of ADT include rapid bone loss. A large 2005 NEJM study found that the bone loss related to ADT leads to the development of fractures. METHODS This is a retrospective cohort study of patients treated with ADT in a radiation oncology (RDE) and medical oncology (SC) practice at an urban academic medical center from 1998-2010. Patients with evidence of bone metastases responsive to ADT were included. Those with androgen independent prostate cancer were excluded. RESULTS 130 patients met the criteria for inclusion and had the characteristics listed in the table. Among the 130 only 3 fractures occurred during 373 patient years of follow up, all within 5 months of ADT initiation. The fracture free survival (FFS) rate at 3 years for all was 97.7%. Excluding fractures occurring within 6 months of ADT initiation the FFS rate was 100% at 3 years. No significant difference was demonstrated in those screened with a pretreatment DEXA scan; there was no relationship between the number of AD cycles, recovery of testosterone to normal or total time on AD. Those with any baseline risk factor of osteoporosis had a trend to an increased risk of fractures (p=0.065); older patients, surprisingly, had a lower risk (p=0.054). Patients with normal BMD had a FFS of 93.8% at 3 yrs, osteopenic patients had 94.7%, and patients with osteoporosis and hormone responsive metastases had 100%. CONCLUSIONS The prevalence of fracture among this group is significantly less than what has previously been reported for men receiving ADT, potentially suggesting an overstatement of risk. Further prospective study with a larger sample size is needed. [Table: see text] No significant financial relationships to disclose.