Laura S. Wood

Sunitinib Mediates Reversal of Myeloid-Derived Suppressor Cell Accumulation in Renal Cell Carcinoma Patients

Purpose: Immune dysfunction reported in renal cell carcinoma (RCC) patients may contribute to tumor progression. Myeloid-derived suppressor cells (MDSC) represent one mechanism by which tumors induce T-cell suppression. Several factors pivotal to the accumulation of MDSC are targeted by the tyrosine kinase inhibitor, sunitinib. The effect of sunitinib on MDSC-mediated immunosuppression in RCC patients has been investigated. Experimental Design: Patient peripheral blood levels of MDSC and regulatory T-cell (Treg) and T-cell production of IFN-γ were evaluated before and after sunitinib treatment. Correlations between MDSC and Treg normalization as well as T-cell production of IFN-γ were examined. The in vitro effect of sunitinib on patient MDSC was evaluated. Results: Metastatic RCC patients had elevated levels of CD33+HLA-DR− and CD15+CD14− MDSC, and these were partially overlapping populations. Treatment with sunitinib resulted in significant reduction in MDSC measured by several criteria. Sunitinib-mediated reduction in MDSC was correlated with reversal of type 1 T-cell suppression, an effect that could be reproduced by the depletion of MDSC in vitro. MDSC reduction in response to sunitinib correlated with a reversal of CD3+CD4+CD25hiFoxp3+ Treg cell elevation. No correlation existed between a change in tumor burden and a change in MDSC, Treg, or T-cell production of IFN-γ. In vitro addition of sunitinib reduced MDSC viability and suppressive effect when used at ≥1.0 μg/mL. Sunitinib did not induce MDSC maturation in vitro. Conclusions: Sunitinib-based therapy has the potential to modulate antitumor immunity by reversing MDSC-mediated tumor-induced immunosuppression.

Validation and Extension of the Memorial Sloan-Kettering Prognostic Factors Model for Survival in Patients With Previously Untreated Metastatic Renal Cell Carcinoma

PURPOSE To validate the Motzer et al prognostic factors model for survival in patients with previously untreated metastatic renal cell carcinoma (RCC) and to identify additional independent prognostic factors. PATIENTS AND METHODS Data were collected on 353 previously untreated metastatic RCC patients enrolled onto clinical trials between 1987 and 2002. RESULTS Four of the five prognostic factors identified by Motzer were independent predictors of survival. In addition, prior radiotherapy and presence of hepatic, lung, and retroperitoneal nodal metastases were found to be independent prognostic factors. Using the number of metastatic sites as surrogate for individual sites (none or one v two or three sites), Motzers definitions of risk groups were expanded to accommodate these two additional prognostic factors. Using this expanded criteria, favorable risk is defined as zero or one poor prognostic factor, intermediate risk is two poor prognostic factors, and poor risk is more than two poor prognostic factors. According to Motzers definitions, 19% of patients were favorable risk, 70% were intermediate risk, and 11% were poor risk; median overall survival times for these groups were 28.6, 14.6, and 4.5 months, respectively (P < .0001). Using the expanded criteria, 37% of patients were favorable risk, 35% were intermediate risk, and 28% were poor risk; median overall survival times of these groups were 26.0, 14.4, and 7.3 months, respectively (P < .0001). CONCLUSION These data validate the model described by Motzer et al. Additional independent prognostic factors identified were prior radiotherapy and sites of metastasis. Incorporation of these additional prognostic factors into the Motzer et al model can help better define favorable risk, intermediate risk, and poor risk patients.

Sunitinib Reverses Type-1 Immune Suppression and Decreases T-Regulatory Cells in Renal Cell Carcinoma Patients

Purpose: Immune dysfunction is well documented in renal cell carcinoma (RCC) patients and likely contributes to tumor evasion. This dysfunction includes a shift from a type-1 to a type-2 T-cell cytokine response and enhanced T-regulatory (Treg) cell expression. Given the antitumor activity of select tyrosine kinase inhibitors such as sunitinib in metastatic RCC (mRCC) patients, it is relevant to assess their effect on the immune system. Experimental Design: Type-1 (IFNγ) and type-2 (interleukin-4) responses were assessed in T cells at baseline and day 28 of treatment with sunitinib (50 mg/d) by measuring intracellular cytokines after in vitro stimulation with anti-CD3/anti-CD28 antibodies. Results: After one cycle of treatment, there was a significant increase in the percentage of IFNγ-producing T cells (CD3+, P < 0.001; CD3+CD4+, P = 0.001), a reduction in interleukin-4 production (CD3+ cells, P = 0.05), and a diminished type-2 bias (P = 0.005). The increase in type-1 response may be partly related to modulation of Treg cells. The increased percentage of Treg cells noted in mRCC patients over healthy donors (P = 0.001) was reduced after treatment, although not reaching statistical significance. There was, however, an inverse correlation between the increase in type-1 response after two cycles of treatment and a decrease in the percentage of Treg cells (r = −0.64, P = 0.01). In vitro studies suggest that the effects of sunitinib on Treg cells are indirect. Conclusions: The demonstration that sunitinib improved type-1 T-cell cytokine response in mRCC patients while reducing Treg function provides a basis for the rational combination of sunitinib and immunotherapy in mRCC.

Phase II Study of Axitinib in Sorafenib-Refractory Metastatic Renal Cell Carcinoma

PURPOSE To investigate the efficacy and safety of axitinib, an oral, potent, and selective inhibitor of vascular endothelial growth factor (VEGF) receptors 1, 2, and 3 in patients with metastatic renal cell carcinoma (mRCC) refractory to prior therapies that included, but were not limited to, sorafenib. PATIENTS AND METHODS In this multicenter, open-label, phase II study, patients with sorafenib-refractory mRCC received a starting dose of axitinib 5 mg orally twice daily. A one-arm, single-stage design was used to estimate the primary end point of objective response rate (ORR), defined by RECIST (Response Evaluation Criteria in Solid Tumors). Secondary end points included safety, duration of response, progression-free survival (PFS), overall survival (OS), and patient-reported outcomes. RESULTS Of 62 patients recruited, 100% had received prior sorafenib, and 74.2% had received two or more prior systemic treatments. The axitinib dose was titrated to greater than 5 mg twice daily in 53.2% of patients, and 35.5% of patients had the dose modified to less than 5 mg twice daily. In 62 patients evaluable for response, the ORR was 22.6%, and the median duration of response was 17.5 months. Median PFS and OS times were 7.4 months (95% CI, 6.7 to 11.0 months) and 13.6 months (95% CI, 8.4 to 18.8 months), respectively. All-causality grade 3 to 4 adverse events included hand-foot syndrome (16.1%), fatigue (16.1%), hypertension (16.1%), dyspnea (14.5%), diarrhea (14.5%), dehydration (8.1%), and hypotension (6.5%). CONCLUSION Axitinib has antitumor activity in patients with mRCC refractory to prior VEGF-targeted therapy, including sorafenib. Toxicities were mild to moderate and were manageable. A randomized, phase III trial to compare axitinib with sorafenib in patients who have mRCC refractory to one prior first-line therapy regimen is underway.

Evolving Strategies for the Management of Hand–Foot Skin Reaction Associated with the Multitargeted Kinase Inhibitors Sorafenib and Sunitinib

The multitargeted kinase inhibitors (MKIs) sorafenib and sunitinib have shown benefit in patients with renal cell carcinoma, hepatocellular carcinoma (sorafenib), and gastrointestinal stromal tumor (sunitinib). Their efficacy in other malignancies is currently being investigated because of their broad range of activity. The effectiveness of these drugs is somewhat diminished by the development of a variety of toxicities, most notably hand-foot skin reaction (HFSR). Although HFSR does not appear to directly affect survival, it can impact quality of life and lead to MKI dose modification or interruption, potentially limiting the antitumor effect. Currently, no standard guidelines exist for the prevention and management of MKI-associated HFSR. To address this issue, an international, interdisciplinary panel of experts gathered in January 2008 to discuss and evaluate the best-practice management of these reactions. Based on these proceedings, recommendations for the management of HFSR have been provided to offer patients the best possible quality of life while taking these drugs and to optimize the patient benefit associated with MKI therapy.

Clinical factors associated with outcome in patients with metastatic clear-cell renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy

Therapy targeted against the vascular endothelial growth factor (VEGF) pathway is a standard of care for patients with metastatic renal cell carcinoma (RCC). The identification of patients who are more likely to benefit from these agents is warranted.

von Hippel-Lindau Gene Status and Response to Vascular Endothelial Growth Factor Targeted Therapy for Metastatic Clear Cell Renal Cell Carcinoma

PURPOSE The von Hippel-Lindau (VHL) gene is often inactivated (by mutation or promoter hypermethylation) in renal cell carcinoma but the relation to therapeutic outcome is unclear. MATERIALS AND METHODS Patients with metastatic clear cell renal cell carcinoma with available baseline tumor samples who received vascular endothelial growth factor targeted therapy were included in analysis. Patient characteristics, VHL gene status and clinical outcome were documented. Our primary end point was to test for response rate in relation to VHL inactivation. Progression-free survival and overall survival in relation to VHL status were investigated as secondary end points. RESULTS A total of 123 patients were evaluable. Response rate, median progression-free survival and median overall survival were 37% (95% CI 28-46), 10.8 (95% CI 7.7-14.8) and 29.8 (CI not estimable) months, respectively. Patients with VHL inactivation had a response rate of 41% vs 31% for those with wild-type VHL (p = 0.34). Patients with loss of function mutations (frameshift, nonsense, splice and in-frame deletions/insertions) had a 52% response rate vs 31% with wild-type VHL (p = 0.04). On multivariate analysis the presence of a loss of function mutation remained an independent prognostic factor associated with improved response. Progression-free survival and overall survival were not significantly different based on VHL status. CONCLUSIONS To our knowledge this is the largest analysis investigating the impact of VHL inactivation on the outcome of vascular endothelial growth factor targeted agents in metastatic renal cell carcinoma. We did not find a statistically significant increase in response to vascular endothelial growth factor targeted agents in patients with VHL inactivation. Loss of function mutations identified a population of patients with a greater response. Investigation of downstream markers is under way.

Metastatic Sarcomatoid Renal Cell Carcinoma Treated With Vascular Endothelial Growth Factor–Targeted Therapy

PURPOSE Metastatic renal cell carcinoma (mRCC) with sarcomatoid differentiation is an aggressive disease that is associated with poor outcomes to chemotherapy or immunotherapy. The utility of vascular endothelial growth factor (VEGF)-targeted therapy in patients with this disease is unknown. PATIENTS AND METHODS Patients who had mRCC with sarcomatoid features in the primary tumor and who were treated with VEGF-targeted therapy were retrospectively identified. Pathology slides were reviewed to determine the percentage of sarcomatoid differentiation. Objective response rate, percentage of tumor burden shrinkage, progression-free survival (PFS), and overall survival (OS) were determined. RESULTS Forty-three patients who had sarcomatoid mRCC were identified. The median percentage of sarcomatoid features was 14% (range, 3% to 90%). Patients were treated with either sunitinib (49%), sorafenib (28%), bevacizumab (19%), or sunitinib plus bevacizumab (5%). Partial responses were observed in eight patients (19%); 21 patients (49%) had stable disease; and 14 patients (33%) had progressive disease as their best response. Partial responses were limited to patients who had underlying clear-cell histology and less than 20% sarcomatoid elements. Median tumor shrinkage was -2% (range, -85% to 127%), and 53% achieved some degree of tumor shrinkage on therapy. Median PFS and OS were estimated to be 5.3 months and 11.8 months, respectively. CONCLUSION Patients who have mRCC and sarcomatoid differentiation can demonstrate objective responses and tumor shrinkage to VEGF-targeted therapy. Patients who have clear-cell histology and a lower percentage of sarcomatoid differentiation may have better outcomes with VEGF-targeted therapy.

A Phase II trial of pegylated liposomal doxorubicin, vincristine, and reduced-dose dexamethasone combination therapy in newly diagnosed multiple myeloma patients.

Patients with multiple myeloma (MM) have increased bone marrow angiogenesis, a low plasma cell labeling index, and multidrug resistance (the primary cause of chemotherapy failure). MM patients receiving the vincristine, doxorubicin, and dexamethasone (VAD) regimen develop resistance and cardiac and steroid toxicity. Pegylated liposomal doxorubicin (Doxil®/CAELYX™) could potentially extend the duration of malignant plasma cell exposure to therapeutic levels of doxorubicin. This Phase II study evaluates combination pegylated liposomal doxorubicin, vincristine, and reduced‐dose dexamethasone in MM patients.

Phase II study of oral bis (aceto) ammine dichloro (cyclohexamine) platinum (IV) (JM-216, BMS-182751) given daily x 5 in hormone refractory prostate cancer (HRPC)

JM-216 is an orally bioavailable platinum compound with activity against many tumor models. The objective of this study was to determine the safety profile and anti-tumor activity of JM-216 in patients with hormone refractory prostate cancer (HRPC) when given orally daily × 5 days. In this open label phase II study JM-216 was administered orally at the dose of 120 mg/m2/d for 5 days every 4 weeks. Patients continued on the therapy until evidence of disease progression or intolerable toxicity developed. Dose escalation and de-escalation were allowed according to patients tolerance. Thirty-nine patients were enrolled onto the study and received a total of 155 courses (median 2, range 1–16) of JM-216. Dose delays (77% of courses) and dose reductions (31% of courses) were common and were mainly due to myelosupression. Treatment was discontinued in 5 patients due to treatment related toxicities. One patient developed myelodysplastic syndrome 11 months after the start of treatment. The most frequent grade III or higher adverse events included thrombocytopenia (54%), neutropenia (52%), anemia (24%) nausea (13%), vomiting (16%) and diarrhea (28%). PSA response was assessed in 32 patients, 10 (26%) had partial response, 14 (36%) had stable disease while PSA progression was seen in 8 (21%) patients. Of 20 (54%) patients with measurable disease two patients had a documented partial response. Although JM-216 had moderate activity in HRPC when given on daily basis for 5 days, it is associated with significant treatment related toxicities in this patient population.