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Purpose This phase III trial evaluated the efficacy and safety of pazopanib versus placebo in patients with locally advanced renal cell carcinoma (RCC) at high risk for relapse after nephrectomy. Patients and Methods A total of 1,538 patients with resected pT2 (high grade) or ≥ pT3, including N1, clear cell RCC were randomly assigned to pazopanib or placebo for 1 year; 403 patients received a starting dose of 800 mg or placebo. To address toxicity attrition, the 800-mg starting dose was lowered to 600 mg, and the primary end point analysis was changed to disease-free survival (DFS) for pazopanib 600 mg versus placebo (n = 1,135). Primary analysis was performed after 350 DFS events in the intent-to-treat (ITT) pazopanib 600 mg group (ITT600mg), and DFS follow-up analysis was performed 12 months later. Secondary end point analyses included DFS with ITT pazopanib 800 mg (ITT800mg) and safety. Results The primary analysis results of DFS ITT600mg favored pazopanib but did not show a significant improvement over placebo (hazard ratio [HR], 0.86; 95% CI, 0.70 to 1.06; P = .165). The secondary analysis of DFS in ITT800mg (n = 403) yielded an HR of 0.69 (95% CI, 0.51 to 0.94). Follow-up analysis in ITT600mg yielded an HR of 0.94 (95% CI, 0.77 to 1.14). Increased ALT and AST were common adverse events leading to treatment discontinuation in the pazopanib 600 mg (ALT, 16%; AST, 5%) and 800 mg (ALT, 18%; AST, 7%) groups. Conclusion The results of the primary DFS analysis of pazopanib 600 mg showed no benefit over placebo in the adjuvant setting. Purpose This phase III trial evaluated the efficacy and safety of pazopanib versus placebo in patients with locally advanced renal cell carcinoma (RCC) at high risk for relapse after nephrectomy. Patients and Methods A total of 1,538 patients with resected pT2 (high grade) or ≥ pT3, including N1, clear cell RCC were randomly assigned to pazopanib or placebo for 1 year; 403 patients received a starting dose of 800 mg or placebo. To address toxicity attrition, the 800-mg starting dose was lowered to 600 mg, and the primary end point analysis was changed to disease-free survival (DFS) for pazopanib 600 mg versus placebo (n = 1,135). Primary analysis was performed after 350 DFS events in the intent-to-treat (ITT) pazopanib 600 mg group (ITT600mg), and DFS follow-up analysis was performed 12 months later. Secondary end point analyses included DFS with ITT pazopanib 800 mg (ITT800mg) and safety. Results The primary analysis results of DFS ITT600mg favored pazopanib but did not show a significant improvement over placebo (hazard ratio [HR], 0.86; 95% CI, 0.70 to 1.06; P = .165). The secondary analysis of DFS in ITT800mg (n = 403) yielded an HR of 0.69 (95% CI, 0.51 to 0.94). Follow-up analysis in ITT600mg yielded an HR of 0.94 (95% CI, 0.77 to 1.14). Increased ALT and AST were common adverse events leading to treatment discontinuation in the pazopanib 600 mg (ALT, 16%; AST, 5%) and 800 mg (ALT, 18%; AST, 7%) groups. Conclusion The results of the primary DFS analysis of pazopanib 600 mg showed no benefit over placebo in the adjuvant setting.

Purpose Sunitinib is a standard initial therapy in metastatic renal cell carcinoma (mRCC), but chronic dosing requires balancing toxicity with clinical benefit. The feasibility and clinical outcome with intermittent sunitinib dosing in patients with mRCC was explored. Patients and Methods Patients with treatment-naïve, clear cell mRCC were treated with four cycles of sunitinib (50 mg once per day, 4 weeks of receiving treatment followed by 2 weeks of no treatment). Patients with a ≥ 10% reduction in tumor burden (TB) after four cycles had sunitinib held, with restaging scans performed every two cycles. Sunitinib was reinitiated for two cycles in those patients with an increase in TB by ≥ 10%, and again held with ≥ 10% TB reduction. This intermittent sunitinib dosing continued until Response Evaluation Criteria in Solid Tumors-defined disease progression while receiving sunitinib, or unacceptable toxicity occurred. The primary objective was feasibility, defined as the proportion of eligible patients who underwent intermittent therapy. Results Of 37 patients enrolled, 20 were eligible for intermittent therapy and all patients (100%) entered the intermittent phase. Patients were not eligible for intermittent sunitinib because of progressive disease (n = 13), toxicity (n = 1), or consent withdrawal (n = 3) before the end of cycle 4. The objective response rate was 46% after the first four cycles of therapy. The median increase in TB during the periods off sunitinib was 1.6 cm (range, −2.9 to 3.4 cm) compared with the TB immediately before stopping sunitinib. Most patients exhibited a stable sawtooth pattern of TB reduction while receiving sunitinib and TB increase while not receiving sunitinib. Median progression-free survival to date is 22.4 months (95% CI, 5.4 to 37.6 months) and median overall survival is 34.8 months (95% CI, 14.8 months to not applicable). Conclusion Periodic extended sunitinib treatment breaks are feasible and clinical efficacy does not seem to be compromised.

Purpose Nivolumab is a fully human immunoglobulin G4 programmed death–1 immune checkpoint inhibitor antibody that restores T-cell immune activity. This phase II trial assessed the antitumor activity, dose-response relationship, and safety of nivolumab in patients with metastatic renal cell carcinoma (mRCC). Patients and Methods Patients with clear-cell mRCC previously treated with agents targeting the vascular endothelial growth factor pathway were randomly assigned (blinded ratio of 1:1:1) to nivolumab 0.3, 2, or 10 mg/kg intravenously once every 3 weeks. The primary objective was to evaluate the dose-response relationship as measured by progression-free survival (PFS); secondary end points included objective response rate (ORR), overall survival (OS), and safety. Results A total of 168 patients were randomly assigned to the nivolumab 0.3- (n = 60), 2- (n = 54), and 10-mg/kg (n = 54) cohorts. One hundred eighteen patients (70%) had received more than one prior systemic regimen. Median PFS was 2.7, 4.0, and 4.2 months, respectively (P = .9). Respective ORRs were 20%, 22%, and 20%. Median OS was 18.2 months (80% CI, 16.2 to 24.0 months), 25.5 months (80% CI, 19.8 to 28.8 months), and 24.7 months (80% CI, 15.3 to 26.0 months), respectively. The most common treatment-related adverse event (AE) was fatigue (24%, 22%, and 35%, respectively). Nineteen patients (11%) experienced grade 3 to 4 treatment-related AEs. Conclusion Nivolumab demonstrated antitumor activity with a manageable safety profile across the three doses studied in mRCC. No dose-response relationship was detected as measured by PFS. These efficacy and safety results in mRCC support study in the phase III setting.

Purpose To prospectively determine the efficacy of combination therapy with temsirolimus plus bevacizumab versus interferon alfa (IFN) plus bevacizumab in metastatic renal cell carcinoma (mRCC). Patients and Methods In a randomized, open-label, multicenter, phase III study, patients with previously untreated predominantly clear-cell mRCC were randomly assigned, stratified by prior nephrectomy and Memorial Sloan-Kettering Cancer Center prognostic group, to receive the combination of either temsirolimus (25 mg intravenously, weekly) or IFN (9 MIU subcutaneously thrice weekly) with bevacizumab (10 mg/kg intravenously, every 2 weeks). The primary end point was independently assessed progression-free survival (PFS). Results Median PFS in patients treated with temsirolimus/bevacizumab (n = 400) versus IFN/bevacizumab (n = 391) was 9.1 and 9.3 months, respectively (hazard ratio [HR], 1.1; 95% CI, 0.9 to 1.3; P = .8). There were no significant differences in overall survival (25.8 ν 25.5 months; HR, 1.0; P = .6) or objective response rate (27.0% ν 27.4%) with temsirolimus/bevacizumab versus IFN/bevacizumab, respectively. Patients receiving temsirolimus/bevacizumab reported significantly higher overall mean scores in the Functional Assessment of Cancer Therapy–Kidney Symptom Index (FKSI) –15 and FKSI-Disease Related Symptoms subscale compared with IFN/bevacizumab (indicating improvement); however, no differences in global health outcome measures were observed. Treatment-emergent all-causality grade ≥ 3 adverse events more common (P < .001) with temsirolimus/bevacizumab were mucosal inflammation, stomatitis, hypophosphatemia, hyperglycemia, and hypercholesterolemia, whereas neutropenia was more common with IFN/bevacizumab. Incidence of pneumonitis with temsirolimus/bevacizumab was 4.8%, mostly grade 1 or 2. Conclusion Temsirolimus/bevacizumab combination therapy was not superior to IFN/bevacizumab for first-line treatment in clear-cell mRCC.

Purpose Foretinib is an oral multikinase inhibitor targeting MET, VEGF, RON, AXL, and TIE-2 receptors. Activating mutations or amplifications in MET have been described in patients with papillary renal cell carcinoma (PRCC). We aimed to evaluate the efficacy and safety of foretinib in patients with PRCC. Patients and Methods Patients were enrolled onto the study in two cohorts with different dosing schedules of foretinib: cohort A, 240 mg once per day on days 1 through 5 every 14 days (intermittent arm); cohort B, 80 mg daily (daily dosing arm). Patients were stratified on the basis of MET pathway activation (germline or somatic MET mutation, MET [7q31] amplification, or gain of chromosome 7). The primary end point was overall response rate (ORR). Results Overall, 74 patients were enrolled, with 37 in each dosing cohort. ORR by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 was 13.5%, median progression-free survival was 9.3 months, and median overall survival was not reached. The presence of a germline MET mutation was highly predictive of a response (five of 10 v five of 57 patients with and without germline MET mutations, respectively). The most frequent adverse events of any grade associated with foretinib were fatigue, hypertension, gastrointestinal toxicities, and nonfatal pulmonary emboli. Conclusion Foretinib demonstrated activity in patients with advanced PRCC with a manageable toxicity profile and a high response rate in patients with germline MET mutations.

Purpose There are no robust data on prognostic factors for overall survival (OS) in patients with metastatic renal cell carcinoma (RCC) treated with vascular endothelial growth factor (VEGF) –targeted therapy. Methods Baseline characteristics and outcomes on 645 patients with anti-VEGF therapy–naïve metastatic RCC were collected from three US and four Canadian cancer centers. Cox proportional hazards regression, followed by bootstrap validation, was used to identify independent prognostic factors for OS. Results The median OS for the whole cohort was 22 months (95% CI, 20.2 to 26.5 months), and the median follow-up was 24.5 months. Overall, 396, 200, and 49 patients were treated with sunitinib, sorafenib, and bevacizumab, respectively. Four of the five adverse prognostic factors according to the Memorial Sloan-Kettering Cancer Center (MSKCC) were independent predictors of short survival: hemoglobin less than the lower limit of normal (P < .0001), corrected calcium greater than the upper limit of normal (ULN; P = .0006), Karnofsky performance status less than 80% (P < .0001), and time from diagnosis to treatment of less than 1 year (P = .01). In addition, neutrophils greater than the ULN (P < .0001) and platelets greater than the ULN (P = .01) were independent adverse prognostic factors. Patients were segregated into three risk categories: the favorable-risk group (no prognostic factors; n = 133), in which median OS (mOS) was not reached and 2-year OS (2y OS) was 75%; the intermediate-risk group (one or two prognostic factors; n = 301), in which mOS was 27 months and 2y OS was 53%; and the poor-risk group (three to six prognostic factors; n = 152), in which mOS was 8.8 months and 2y OS was 7% (log-rank P < .0001). The C-index was 0.73. Conclusion This model validates components of the MSKCC model with the addition of platelet and neutrophil counts and can be incorporated into patient care and into clinical trials that use VEGF-targeted agents.

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.

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.

Purpose Bevacizumab is an antibody that binds to vascular endothelial growth factor (VEGF) and has activity in metastatic renal cell carcinoma (RCC). Interferon alfa (IFN) is a historic standard first-line treatment for RCC. A prospective, randomized phase III trial of bevacizumab plus IFN versus IFN monotherapy was conducted. Patients and Methods Patients with previously untreated, metastatic clear-cell RCC were randomly assigned to receive either bevacizumab (10 mg/kg intravenously every 2 weeks) plus IFN (9 million U subcutaneously three times weekly) or the same dose and schedule of IFN monotherapy in a multicenter phase III trial. The primary end point was overall survival (OS). Secondary end points were progression-free survival (PFS), objective response rate (ORR), and safety. Results Between October 2003 and July 2005, 732 patients were enrolled. The prespecified stopping rule for OS has not yet been reached. The median PFS was 8.5 months in patients receiving bevacizumab plus IFN (95% CI, 7.5 to 9.7 months) versus 5.2 months (95% CI, 3.1 to 5.6 months) in patients receiving IFN monotherapy (log-rank P < .0001). The adjusted hazard ratio was 0.71 (95% CI, 0.61 to 0.83; P < .0001). Bevacizumab plus IFN had a higher ORR as compared with IFN (25.5% [95% CI, 20.9% to 30.6%] v 13.1% [95% CI, 9.5% to 17.3%]; P < .0001). Overall toxicity was greater for bevacizumab plus IFN, including significantly more grade 3 hypertension (9% v 0%), anorexia (17% v 8%), fatigue (35% v 28%), and proteinuria (13% v 0%). Conclusion Bevacizumab plus IFN produces a superior PFS and ORR in untreated patients with metastatic RCC as compared with IFN monotherapy. Toxicity is greater in the combination therapy arm.

Purpose To assess the safety and efficacy of sunitinib in patients with bevacizumab-refractory metastatic renal cell carcinoma (mRCC) and explore biomarkers for sunitinib response. Patients and Methods Patients with mRCC and disease progression after bevacizumab-based therapy received oral sunitinib 50 mg once daily in 6-week cycles on a 4/2 schedule (4 weeks with treatment followed by 2 weeks without treatment) in a phase II multicenter study. The primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), duration of response (DR), overall survival (OS), and safety. Plasma soluble proteins (vascular endothelial growth factor [VEGF]-A, VEGF-C, soluble VEGF receptor [sVEGFR]-3, and placental growth factor [PlGF]) levels were measured. Results Sixty-one patients were enrolled. The ORR was 23.0% (95% CI, 13.2% to 35.5%), median PFS was 30.4 weeks (95% CI, 18.3 to 36.7 weeks), median DR was 44.1 weeks (95% CI, 25.0 to 102.7 weeks), and median OS was 47.1 weeks (95% CI, 36.9 to 79.4 weeks). Mean plasma VEGF-A and PlGF levels significantly increased whereas VEGF-C and sVEGFR-3 levels decreased with sunitinib treatment. Lower baseline levels of sVEGFR-3 and VEGF-C were associated with longer PFS and ORR. Most treatment-related adverse events were of mild-to-moderate intensity and included fatigue, hypertension, and hand-foot syndrome. Conclusion Sunitinib has substantial antitumor activity in patients with bevacizumab-refractory mRCC and modulates circulating VEGF pathway biomarkers. These data support the hypothesis that sunitinib inhibits signaling pathways involved in bevacizumab resistance. Baseline levels of sVEGFR-3 and VEGF-C may have potential utility as biomarkers of clinical efficacy in this setting.

Purpose Renal cell carcinoma (RCC) is characterized by loss of von Hippel Lindau tumor suppressor gene activity, resulting in high expression of pro-angiogenic growth factors: vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). SU11248 (sunitinib malate), a small molecule inhibitor with high binding affinity for VEGF and PDGF receptors, was tested for clinical activity in patients with metastatic RCC. Patients and Methods Patients with metastatic RCC and progression on first-line cytokine therapy were enrolled onto a multicenter phase II trial. SU11248 monotherapy was administered in repeated 6-week cycles of daily oral therapy for 4 weeks, followed by 2 weeks off. Overall response rate was the primary end point, and time to progression and safety were secondary end points. Results Twenty-five (40%) of 63 patients treated with SU11248 achieved partial responses; 17 additional patients (27%) demonstrated stable disease lasting ≥ 3 months. Median time to progression in the 63 patients was 8.7 months. Dosing was generally tolerated with manageable toxicities. Conclusion SU11248, a multitargeted receptor tyrosine kinase inhibitor of VEGF and PDGF receptors, demonstrates antitumor activity in metastatic RCC as second-line therapy, a setting where no effective systemic therapy is presently recognized. The genetics of RCC and these promising clinical results support the hypothesis that VEGF and PDGF receptor-mediated signaling is an effective therapeutic target in RCC.

PurposeTo review the biology of renal cell carcinoma (RCC) leading to vascular endothelial growth factor (VEGF) overexpression and the clinical results of VEGF blockade in metastatic RCC.MethodsA review of relevant published literature regarding VEGF, von Hippel-Lindau (VHL) gene inactivation and VEGF overexpression in RCC was performed. Further, a review of the mechanism, toxicity, and clinical development of VEGF-targeted therapy in metastatic RCC was undertaken.ResultsVEGF is the major proangiogenic protein that exerts a biologic effect through interaction with cellular receptors. The majority of sporadic clear-cell RCC tumors are characterized by VHL tumor suppressor gene inactivation. The resulting VHL gene silencing leads to VEGF overexpression. An antibody to VEGF (bevacizumab) has demonstrated a significant prolongation of time to disease progression compared with placebo in patients with metastatic RCC. Small molecules with inhibitory effects against the VEGF receptor have undergone initial clinical testing in metastatic RCC with substantial objective response rates.ConclusionTherapeutic targeting of VEGF in RCC has strong biologic rationale and preliminary clinical efficacy. Further investigation will determine the optimal timing, sequence, and utility of these agents in RCC.

Purpose To evaluate the herbal combination, PC-SPES, and diethylstilbestrol (DES) in patients with androgen independent prostate cancer (AIPC). Patients and Methods A randomized phase II study was conducted with cross-over design. Patients were randomly assigned to receive either three PC-SPES capsules orally three times a day or DES 3 mg orally once a day. Prophylactic warfarin was administered. At clinical or prostate-specific antigen progression, patients received the other therapy. The study closed prematurely after PC-SPES was withdrawn from the market. Chemical analyses were performed on multiple lots of PC-SPES. Results Ninety patients were enrolled, of whom 85 were assessable for response. Prostate-specific antigen declines ≥ 50% were noted in 40% (95% CI, 25% to 56%) with PC-SPES, and 24% (95% CI, 12% to 39%) with DES. Median response duration was not reached with PC-SPES, and was 3.8 months with DES. Median time to progression for randomly assigned patients was 5.5 months for PC-SPES and 2.9 months for DES. Common toxicities included mild fatigue, gynecomastia, and mastodynia. Five thromboembolic events occurred (one PC-SPES, four DES). Responses in the cross-over phase were inconclusive. Four lots of PC-SPES had measurable quantities of DES, ranging from 0.01% to 3.1% of the dose used in the DES arm. Ethinyl estradiol was also detected in PC-SPES lots. Conclusion PC-SPES and DES demonstrate activity in AIPC and are well tolerated. However, the synthetic estrogens, DES and ethinyl estradiol, were detected in various lots of PC-SPES, including those used in this trial. Clinical trials that utilize herbal therapies must account for issues of purity and consistency.

Purpose Antiandrogen withdrawal (AAWD) results in a prostate-specific antigen (PSA) response (decline in PSA level of ≥ 50%) in 15% to 30% of androgen-independent prostate cancer (AiPCa) patients. Thereafter, adrenal androgen ablation with agents such as ketoconazole (K) is commonly utilized. The therapeutic effect of AAWD alone was compared with simultaneous AAWD and K therapy. Patients and Methods AiPCa patients were randomized to undergo AAWD alone (n = 132), or together with K (400 mg orally [po] tid) and hydrocortisone (30 mg po each morning, 10 mg po each evening; n = 128). Patients who developed progressive disease after AAWD alone were eligible for deferred treatment with K. Results Eleven percent of patients undergoing AAWD alone had a PSA response, compared to 27% of patients who underwent AAWD and simultaneous K (P = .0002). Objective responses were observed in 2% of patients treated with AAWD alone compared to 20% in patients treated with AAWD/K (P = .02). There was no difference in survival. PSA and objective responses were observed in 32% and 7%, respectively, of patients receiving deferred K, and were more common in patients with prior AAWD response. Treatment with K was well tolerated, and resulted in a decline in adrenal androgen levels, which rose at the time of disease progression. Conclusion K has modest activity in AiPCa patients, while AAWD alone has minimal activity. Adrenal androgen levels fall with treatment with K and then climb at the time of progression, suggesting that progressive disease while on K may be due to tachyphylaxis to the adrenolytic properties of K.

Purpose: To determine the biologic effect of granulocyte-macrophage colony-stimulating factor (sangramostim, GM-CSF; Immunex Corporation, Seattle, WA) as measured by prostate-specific antigen (PSA) kinetics in patients with serologic progression of prostate cancer after definitive local therapy. Patients and Methods: Patients with prostate cancer who had undergone previous definitive surgical or radiation therapy with nonmetastatic, recurrent disease as manifested by a rising PSA between 0.4 ng/mL and 6.0 ng/mL were enrolled on this phase II trial. Patients received 250 μg/m2/day of subcutaneous GM-CSF on days 1 through 14 of a 28-day cycle. PSA was measured at day 1 of each cycle. Results: Thirty patients with serologic progression of prostate cancer were treated. The median pretreatment PSA was 2.9 ng/mL. Of the 29 evaluable patients, three patients (10%; 95% confidence interval, 2% to 27%) achieved a 50% reduction in PSA. For the patients (n = 26) in whom the on-treatment PSA doubling time could be calculated, the median PSA doubling time increased from 8.4 months to 15 months (P = .001), and the median slope of the PSA versus time curve decreased with treatment (P = .004). Therapy was well tolerated by all patients, with an average treatment duration of 16.5 cycles (range, 5 to 33). Conclusion: GM-CSF has a biologic effect in patients with serologic progression of prostate cancer after definitive local therapy, as measured by PSA declines and modulation of PSA kinetics.

PURPOSE: To evaluate the feasibility and safety of nonmyeloablative allogeneic stem-cell transplantation in patients with metastatic renal cell cancer (RCC) and to evaluate efficacy with respect to engraftment and tumor regression. PATIENTS AND METHODS: Between February 1999 and June 2001, patients with refractory, metastatic RCC were screened for enrollment. A fludarabine and cyclophosphamide–based conditioning regimen was used. Patients received granulocyte-macrophage colony-stimulating factor–mobilized, unmanipulated stem cells from a 6/6 HLA-matched sibling donor. Prophylaxis against graft rejection and graft-versus-host disease (GVHD) included tacrolimus and mycophenolate mofetil. RESULTS: A total of 284 patients with metastatic RCC were seen during this time period. Eighty-four patients who had siblings available for HLA typing were actively screened for enrollment, and 15 patients have undergone treatment. Durable donor engraftment was achieved in one of the first four patients treated. Patients no. 5 through 15 received a more immunosuppressive conditioning regimen, and all have achieved sustained donor engraftment. In the 12 patients with at least 180 days of follow-up, acute GVHD has occurred in two patients and chronic GVHD in six patients, with four transplant-related mortalities. Four partial responses have been observed (response rate, 33% in all patients; 44% in the nine patients with sustained donor engraftment). CONCLUSION: Nonmyeloablative allogeneic stem-cell transplantation is feasible for a minority of patients with metastatic RCC. Adequately immunosuppressive conditioning is required for sustained donor engraftment, which is required for an antitumor response. Acute and chronic GVHD are the major causes of substantial morbidity and mortality. Metastatic RCC is susceptible to a graft-versus-tumor effect promoted by allogeneic stem-cell transplantation.