TROPHY-U-01, a phase II open-label study of sacituzumab govitecan in patients with metastatic urothelial carcinoma progressing after platinum-based chemotherapy and checkpoint inhibitors: updated safety and efficacy outcomes.

BACKGROUND: Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate containing cytotoxic SN-38, the active metabolite of irinotecan. SG received accelerated US Food and Drug Administration approval for locally advanced (LA) or metastatic urothelial carcinoma (mUC) previously treated with platinum-based chemotherapy and a checkpoint inhibitor, based on cohort 1 of the TROPHY-U-01 study. Mutations in the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene are associated with increased adverse events (AEs) with irinotecan-based therapies. Whether UGT1A1 status could impact SG toxicity and efficacy remains unclear. PATIENTS AND METHODS: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, phase II registrational study. Cohort 1 includes patients with LA or mUC who progressed after platinum- and checkpoint inhibitor-based therapies. SG was administered at 10 mg/kg intravenously on days 1 and 8 of 21-day cycles. The primary endpoint was objective response rate (ORR) per central review; secondary endpoints included progression-free survival, overall survival, and safety. Post hoc safety analyses were exploratory with descriptive statistics. Updated analyses include longer follow-up. RESULTS: Cohort 1 included 113 patients. At a median follow-up of 10.5 months, ORR was 28% (95% CI 20.2% to 37.6%). Median progression-free survival and overall survival were 5.4 months (95% CI 3.5-6.9 months) and 10.9 months (95% CI 8.9-13.8 months), respectively. Occurrence of grade ≥3 treatment-related AEs and treatment-related discontinuation were consistent with prior reports. UGT1A1 status was wildtype (∗1|∗1) in 40%, heterozygous (∗1|∗28) in 42%, homozygous (∗28|∗28) in 12%, and missing in 6% of patients. In patients with ∗1|∗1, ∗1|∗28, and ∗28|∗28 genotypes, any grade treatment-related AEs occurred in 93%, 94%, and 100% of patients, respectively, and were managed similarly regardless of UGT1A1 status. CONCLUSIONS: With longer follow-up, the ORR remains high in patients with heavily pretreated LA or mUC. Safety data were consistent with the known SG toxicity profile. AE incidence varied across UGT1A1 subgroups; however, discontinuation rates remained relatively low for all groups.

EV-301 long-term outcomes: 24-month findings from the phase III trial of enfortumab vedotin versus chemotherapy in patients with previously treated advanced urothelial carcinoma.

INTRODUCTION: This exploratory analysis evaluated efficacy and safety data for enfortumab vedotin versus chemotherapy over a median follow-up of ∼2 years from EV-301. MATERIALS AND METHODS: Patients with locally advanced/metastatic urothelial carcinoma with prior platinum-containing chemotherapy and disease progression during/after programmed cell death protein 1/ligand 1 inhibitor treatment were randomized to enfortumab vedotin or chemotherapy (docetaxel, paclitaxel, vinflunine). Endpoints were overall survival (primary), progression-free survival (PFS), objective response, and safety. RESULTS: In total, 608 patients were included (enfortumab vedotin, n = 301; chemotherapy, n = 307). With a median follow-up of 23.75 months, 444 deaths had occurred (enfortumab vedotin, n = 207; chemotherapy, n = 237). Risk of death was reduced by 30% with enfortumab vedotin versus chemotherapy [hazard ratio (HR) 0.70 (95% confidence interval [CI] 0.58-0.85); one-sided, log-rank P = 0.00015]; PFS improved with enfortumab vedotin [HR 0.63 (95% CI 0.53-0.76); one-sided, log-rank P < 0.00001]. Treatment-related adverse event rates were 93.9% for enfortumab vedotin and 91.8% for chemotherapy; grade ≥ 3 event rates were 52.4% and 50.5%, respectively. Grade ≥ 3 treatment-related decreased neutrophil count (14.1% versus 6.1%), decreased white blood cell count (7.2% versus 1.4%), and anemia (7.9% versus 2.7%) were more common with chemotherapy versus enfortumab vedotin; maculopapular rash (7.4% versus 0%), fatigue (6.8% versus 4.5%), and peripheral sensory neuropathy (5.1% versus 2.1%) were more common with enfortumab vedotin. Of special interest adverse events, treatment-related skin reactions occurred in 47.3% of patients receiving enfortumab vedotin and 15.8% of patients receiving chemotherapy; peripheral neuropathy occurred in 48.0% versus 31.6%, respectively, and hyperglycemia in 6.8% versus 0.3%. CONCLUSIONS: After a median follow-up of ∼2 years, enfortumab vedotin maintained clinically meaningful overall survival benefit versus chemotherapy, consistent with findings from the EV-301 primary analysis; PFS and overall response benefit remained consistent. Adverse events were manageable; no new safety signals were observed.

Efficacy and safety of pembrolizumab in metastatic urothelial carcinoma: results from KEYNOTE-045 and KEYNOTE-052 after up to 5 years of follow-up.

BACKGROUND: Immune checkpoint inhibitors are a standard therapy in metastatic urothelial carcinoma (UC). Long-term follow-up is necessary to confirm durability of response and identify further safety concerns. PATIENTS AND METHODS: In KEYNOTE-045, patients with metastatic UC that progressed on platinum-containing chemotherapy were randomly assigned 1:1 to receive pembrolizumab or investigator's choice of paclitaxel, docetaxel, or vinflunine. Primary endpoints were progression-free survival per RECIST version 1.1 by blinded independent central review (BICR) and overall survival. In KEYNOTE-052, cisplatin-ineligible patients with metastatic UC received first-line pembrolizumab. The primary endpoint was objective response rate per RECIST version 1.1 by BICR. RESULTS: A total of 542 patients (pembrolizumab, n = 270; chemotherapy, n = 272) were randomly assigned in KEYNOTE-045. The median follow-up was 62.9 months (range 58.6-70.9 months; data cut-off 1 October 2020). At 48 months, overall survival rates were 16.7% for pembrolizumab and 10.1% for chemotherapy; progression-free survival rates were 9.5% and 2.7%, respectively. The median duration of response (DOR) was 29.7 months (range 1.6+ to 60.5+ months) for pembrolizumab and 4.4 months (range 1.4+ to 63.1+ months) for chemotherapy; 36-month DOR rates were 44.4% and 28.3%, respectively. A total of 370 patients were enrolled in KEYNOTE-052. The median follow-up was 56.3 months (range 51.2-65.3 months; data cut-off 26 September 2020). The confirmed objective response rate was 28.9% (95% confidence interval 24.3-33.8), and the median DOR was 33.4 months (range 1.4+ to 60.7+ months); the 36-month DOR rate was 44.8%. Most treatment-related adverse events for pembrolizumab in either study were grade 1 or 2 and manageable, which is consistent with prior reports. CONCLUSION: With ∼5 years of follow-up, pembrolizumab monotherapy continued to demonstrate durable efficacy with no new safety signals in patients with platinum-resistant metastatic UC and as first-line therapy in cisplatin-ineligible patients. CLINICAL TRIAL REGISTRY AND ID: With ClinicalTrials.gov NCT02256436 (KEYNOTE-045); https://clinicaltrials.gov/ct2/show/NCT02256436 and NCT02335424 (KEYNOTE-052); https://clinicaltrials.gov/ct2/show/NCT02335424.

A randomized phase IIa study of quantified bone scan response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with radium-223 dichloride alone or in combination with abiraterone acetate/prednisone or enzalutamide.

BACKGROUND: In metastatic castration-resistant prostate cancer (mCRPC), assessing treatment response and bone lesions with technetium-99m is limited by image resolution and subjectivity. We evaluated bone scan lesion area (BSLA), a quantitative imaging assessment of response in patients with mCRPC receiving radium-223 alone or in combination with androgen receptor pathway inhibitors (abiraterone/prednisone or enzalutamide). PATIENTS AND METHODS: This randomized, non-comparative phase IIa three-arm trial (NCT02034552) evaluated technetium-99m-based BSLA response rate (RR), safety, radiologic progression-free survival (rPFS), and time to first symptomatic skeletal event (SSE) in men with mCRPC and bone metastases receiving radium-223 with/without abiraterone/prednisone or enzalutamide. The primary endpoint was week 24 BSLA RR. RESULTS: Overall, 63 patients received treatment (abiraterone/prednisone combination, n = 22; enzalutamide combination, n = 22; radium-223 monotherapy, n = 19). Median treatment duration (first to last dose of any study treatment) was 12 months (abiraterone/prednisone combination), 10 months (enzalutamide combination), and 3 months (radium-223 monotherapy). Week 24 BSLA RR was 58% [80% confidence interval (CI) 41% to 74%; one-sided P < 0.0001; 11/19 patients] with abiraterone/prednisone combination, 50% (32% to 68%; one-sided P < 0.0001; 8/16 patients) with enzalutamide combination, and 22% (10% to 40%; one-sided P = 0.0109; 4/18 patients) with radium-223 monotherapy. Median rPFS was not evaluable for combination arms and 4 months (80% CI 4 to 12) for monotherapy. SSEs were reported in 32% of patients; median time to first SSE was not estimable. Fatigue and back pain were the most commonly reported treatment-emergent adverse events (TEAEs); more patients receiving combination therapy than monotherapy had TEAEs. Fractures were reported in 18% receiving abiraterone/prednisone, 32% receiving enzalutamide, and 11% receiving radium-223 monotherapy. Fracture rates were lower in patients taking bone health agents versus not taking bone health agents at baseline. CONCLUSIONS: Technetium-99m imaging BSLA may offer objective, quantifiable assessment of isotope uptake changes, and potentially treatment response, in patients with mCRPC and bone metastases treated with radium-223 alone or in combination with abiraterone/prednisone or enzalutamide. In this largely treatment-naive population, BSLA RR was numerically lower with radium-223 monotherapy versus combination therapy, indicating a limited role as first-line treatment. Use of radium-223 should follow evidence-based treatment guidelines and the licensed indication.

Clinical outcomes in men of diverse ethnic backgrounds with metastatic castration-resistant prostate cancer.

BACKGROUND: We have shown previously in multivariable analysis that black men had 19% lower risk of death than white men with metastatic castration-resistant prostate cancer (mCRPC) treated with a docetaxel and prednisone (DP)-based regimen. The primary goal of this analysis was to compare progression-free survival (PFS), biochemical PFS, ≥50% decline in prostate-specific antigen (PSA) from baseline and objective response rate (ORR) in white, black and Asian men with mCRPC treated with a DP-based regimen. PATIENTS AND METHODS: Individual patient data from 8820 mCRPC men randomized on nine phase III trials to a DP-containing regimen were combined. Race used in the analysis was based on self-report. End points were PFS, biochemical PSA, ≥50% decline in PSA from baseline and ORR. The proportional hazards and the logistic regression models were employed to assess the prognostic importance of race in predicting outcomes adjusting for established prognostic factors. RESULTS: Of 8820 patients, 7528 (85%) were white, 500 (6%) were black, 424 were Asian (5%) and 368 (4%) had race unspecified. Median PFS were 8.3 [95% confidence interval (CI) 8.2-8.5], 8.2 (95% CI 7.4-8.8) and 8.3 (95% CI 7.6-8.8) months in white, black and Asian men, respectively. Median PSA PFS were 9.9 (95% CI 9.7-10.4), 8.5 (95% CI 8.0-10.3) and 11.1 (95% CI 9.9-12.5) months in white, black and Asian men, respectively. CONCLUSIONS: We observed no differences in clinical outcomes by race and ethnic groups in men with mCRPC enrolled on these phase III clinical trials with DP.

Randomized phase III KEYNOTE-045 trial of pembrolizumab versus paclitaxel, docetaxel, or vinflunine in recurrent advanced urothelial cancer: results of >2 years of follow-up.

BACKGROUND: Novel second-line treatments are needed for patients with advanced urothelial cancer (UC). Interim analysis of the phase III KEYNOTE-045 study showed a superior overall survival (OS) benefit of pembrolizumab, a programmed death 1 inhibitor, versus chemotherapy in patients with advanced UC that progressed on platinum-based chemotherapy. Here we report the long-term safety and efficacy outcomes of KEYNOTE-045. PATIENTS AND METHODS: Adult patients with histologically/cytologically confirmed UC whose disease progressed after first-line, platinum-containing chemotherapy were enrolled. Patients were randomly assigned 1 : 1 to receive pembrolizumab [200 mg every 3 weeks (Q3W)] or investigator's choice of paclitaxel (175 mg/m2 Q3W), docetaxel (75 mg/m2 Q3W), or vinflunine (320 mg/m2 Q3W). Primary end points were OS and progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1) by blinded independent central radiology review (BICR). A key secondary end point was objective response rate per RECIST v1.1 by BICR. RESULTS: A total of 542 patients were enrolled (pembrolizumab, n = 270; chemotherapy, n = 272). Median follow-up as of 26 October 2017 was 27.7 months. Median 1- and 2-year OS rates were higher with pembrolizumab (44.2% and 26.9%, respectively) than chemotherapy (29.8% and 14.3%, respectively). PFS rates did not differ between treatment arms; however, 1- and 2-year PFS rates were higher with pembrolizumab. The objective response rate was also higher with pembrolizumab (21.1% versus 11.0%). Median duration of response to pembrolizumab was not reached (range 1.6+ to 30.0+ months) versus chemotherapy (4.4 months; range 1.4+ to 29.9+ months). Pembrolizumab had lower rates of any grade (62.0% versus 90.6%) and grade ≥3 (16.5% versus 50.2%) treatment-related adverse events than chemotherapy. CONCLUSIONS: Long-term results (>2 years' follow-up) were consistent with those of previously reported analyses, demonstrating continued clinical benefit of pembrolizumab over chemotherapy for efficacy and safety for treatment of locally advanced/metastatic, platinum-refractory UC. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02256436.

Atezolizumab in platinum-treated locally advanced or metastatic urothelial carcinoma: post-progression outcomes from the phase II IMvigor210 study.

BACKGROUND: Conventional criteria for tumor progression may not fully reflect the clinical benefit of immunotherapy or appropriately guide treatment decisions. The phase II IMvigor210 study demonstrated the efficacy and safety of atezolizumab, a programmed death-ligand 1-directed antibody, in patients with platinum-treated locally advanced or metastatic urothelial carcinoma. Patients could continue atezolizumab beyond Response Evaluation Criteria In Solid Tumors (RECIST) v1.1 progression at the investigator's discretion: this analysis assessed post-progression outcomes in these patients. PATIENTS AND METHODS: Patients were treated with atezolizumab 1200 mg i.v. every 3 weeks until loss of clinical benefit. Efficacy and safety outcomes in patients who experienced RECIST v1.1 progression and did, or did not, continue atezolizumab were analyzed descriptively. RESULTS: In total, 220 patients who experienced progression from the overall cohort (n = 310) were analyzed: 137 continued atezolizumab for ≥ 1 dose after progression, 19 received other systemic therapy, and 64 received no further systemic therapy. Compared with those who discontinued, patients continuing atezolizumab beyond progression were more likely to have had a baseline Eastern Cooperative Oncology Group performance status of 0 (43.1% versus 31.3%), less likely to have had baseline liver metastases (27.0% versus 41.0%), and more likely to have had an initial response to atezolizumab (responses in 11.7% versus 1.2%). Five patients (3.6%) continuing atezolizumab after progression had subsequent responses compared with baseline measurements. Median post-progression overall survival was 8.6 months in patients continuing atezolizumab, 6.8 months in those receiving another treatment, and 1.2 months in those receiving no further treatment. Atezolizumab exposure-adjusted adverse event frequencies were generally similar before and following progression. CONCLUSION: In this single-arm study, patients who continued atezolizumab beyond RECIST v1.1 progression derived prolonged clinical benefit without additional safety signals. Identification of patients most likely to benefit from atezolizumab beyond progression remains an important challenge in the management of metastatic urothelial carcinoma. CLINICALTRIALS.GOV ID: NCT02108652.

Borealis-1: a randomized, first-line, placebo-controlled, phase II study evaluating apatorsen and chemotherapy for patients with advanced urothelial cancer.

BACKGROUND: Five-year survival of patients with inoperable, advanced urothelial carcinoma treated with the first-line chemotherapy is 5%-15%. We assessed whether the Hsp27 inhibitor apatorsen combined with gemcitabine plus cisplatin (GC) could improve overall survival (OS) in these patients. PATIENTS AND METHODS: This placebo-controlled, double-blind, phase II trial randomized 183 untreated urothelial carcinoma patients (North America and Europe) to receive GC plus either placebo (N = 62), 600 mg apatorsen (N = 60), or 1000 mg apatorsen (N = 61). In the experimental arm, treatment included loading doses of apatorsen followed by up to six cycles of apatorsen plus GC. Patients receiving at least four cycles could continue apatorsen monotherapy as maintenance until progression or unacceptable toxicity. The primary end point was OS. RESULTS: OS was not significantly improved in the single or combined 600- or 1000-mg apatorsen arms versus placebo [hazard ratio (HR), 0.86 and 0.90, respectively]. Exploratory study of specific statistical modeling showed a trend for improved survival in patients with baseline poor prognostic features treated with 600 mg apatorsen compared with placebo (HR = 0.72). Landmark analysis of serum Hsp27 (sHsp27) levels showed a trend toward survival benefit for poor-prognosis patients in 600- and 1000-mg apatorsen arms who achieved lower area under the curve sHsp27 levels, compared with the placebo arm (HR = 0.45 and 0.62, respectively). Higher baseline circulating tumor cells (≥5 cells/7.5 ml) was observed in patients with poor prognosis in correlation with poor survival. Treatment-emergent adverse events were manageable and more common in both apatorsen-treatment arms. CONCLUSIONS: Even though apatorsen combined with standard chemotherapy did not demonstrate a survival benefit in the overall study population, patients with poor prognostic features might benefit from this combination. Serum Hsp27 levels may act as a biomarker to predict treatment outcome. Further exploration of apatorsen in poor-risk patients is warranted.

Phase I/II trial of cabazitaxel plus abiraterone in patients with metastatic castration-resistant prostate cancer (mCRPC) progressing after docetaxel and abiraterone.

Background: Abiraterone and cabazitaxel improve survival in patients with metastatic castration-resistant prostate cancer (mCRPC). We conducted an open-label phase I/II trial of cabazitaxel plus abiraterone to assess the antitumor activity and tolerability in patients with progressive mCRPC after docetaxel (phase I), and after docetaxel and abiraterone (phase II) (NCT01511536). Patients and methods: The primary objectives were to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of cabazitaxel plus abiraterone (phase I), and the prostate-specific antigen (PSA) response defined as a ≥ 50% decrease confirmed ≥3 weeks later with this combination (phase II). Results: Ten patients were enrolled in the phase I component; nine were evaluable. No DLTs were identified. The MTD was established as the approved doses for both drugs (cabazitaxel 25 mg/m2 every 3 weeks and abiraterone 1000 mg once daily). Daily abiraterone treatment did not impact on cabazitaxel clearance. Twenty-seven patients received cabazitaxel plus abiraterone plus prednisone (5 mg twice daily) in phase II. The median number of cycles administered (cabazitaxel) was seven (range: 1-28). Grade 3-4 treatment-emergent adverse events included asthenia (in 5 patients; 14%), neutropenia (in 5 patients; 14%) and diarrhea (in 3 patients; 8%). Nine patients (24%) required dose reductions of cabazitaxel. Of 26 evaluable patients, 12 achieved a PSA response [46%; 95% confidence interval (CI): 26.6-66.6%]. Median PSA-progression-free survival was 6.9 months (95% CI: 4.1-10.3 months). Of 14 patients with measurable disease at baseline, 3 (21%) achieved a partial response per response evaluation criteria in solid tumors. Conclusions: The combination of cabazitaxel and abiraterone has a manageable safety profile and shows antitumor activity in patients previously treated with docetaxel and abiraterone.

Time to disease-related pain and first opioid use in patients with metastatic castration-resistant prostate cancer treated with sipuleucel-T.

BACKGROUND: Sipuleucel-T has demonstrated improved overall survival in patients with metastatic castration-resistant prostate cancer (mCRPC). This analysis examined the effect of sipuleucel-T on time to disease-related pain (TDRP) and time to first use of opioid analgesics (TFOA) in mCRPC using data pooled from three randomized phase III studies in men with asymptomatic or minimally symptomatic mCRPC (D9901 (NCT00005947), D9902A (NCT01133704), D9902B (IMPACT; NCT00065442)). METHODS: Four-hundred and twenty-eight asymptomatic patients were analyzed for TDRP; 737 patients were analyzed for TFOA. Pain status was collected using logs adjudicated by blinded, independent reviewers. Opioid use for cancer-related pain was identified from medically reviewed reports of concomitant medication. Disease-related pain was defined as pain post enrollment. TDRP and TFOA were analyzed using the Kaplan-Meier method and Cox regression. RESULTS: Treatment with sipuleucel-T was not associated with a significant difference in TDRP (hazard ratio (HR)=0.819; 95% confidence interval (CI): 0.616-1.089; P=0.170; median TDRP 5.6 months for sipuleucel-T and 5.3 months for control, respectively), although 39.3% of sipuleucel-T-treated patients and 18.9% of control patients were pain-free at 12 months. However, there was a significant delay in TFOA with sipuleucel-T (HR=0.755; 95% CI: 0.579-0.985; P=0.038). Median TFOA for sipuleucel-T was 12.6, and 9.7 months for control, with 50.6% and 43.1% opioid-free at 12 months, respectively. Kaplan-Meier curves for both end points began to diverge at 6 months. CONCLUSIONS: Sipuleucel-T was associated with longer TFOA but not significantly longer TDRP. Both end points demonstrated evidence of a delayed treatment effect, consistent with an active immunotherapy.

Phase II study of eribulin mesylate (E7389) in patients with metastatic castration-resistant prostate cancer stratified by prior taxane therapy.

BACKGROUND: Treatment options remain limited for patients with castration-resistant prostate cancer (CRPC). We evaluated eribulin mesylate (E7389), a nontaxane halichondrin B analog microtubule inhibitor, in patients with metastatic CRPC with or without previous taxane exposure. PATIENTS AND METHODS: Men with histologically proven CRPC, with or without prior taxane exposure, were enrolled in an open-label, single-arm phase II trial. Patients received eribulin mesylate 1.4 mg/m(2) as a 2- to 5-min i.v. bolus infusion on days 1 and 8 of a 21-day cycle. The primary efficacy end point was prostate-specific antigen (PSA) response rate. RESULTS: In total, 108 patients were assessable for safety (50 were taxane-pretreated) and 105 for efficacy in the per-protocol population. The median age of patients was 71 years and median number of cycles was 4. PSA decreases of ≥ 50% were achieved in 22.4% and 8.5% of taxane-naive and taxane-pretreated patients, respectively. The most common grade 3/4 adverse event was neutropenia, seen in 22.4% of chemo-naive and 40% of taxane-pretreated men. Grade 3 peripheral neuropathy occurred in none of the taxane-naive patients and 6.0% of taxane-pretreated patients. CONCLUSION: Eribulin mesylate demonstrated activity and a relatively favorable toxicity profile in metastatic CRPC.

A phase I trial of pox PSA vaccines (PROSTVAC-VF) with B7-1, ICAM-1, and LFA-3 co-stimulatory molecules (TRICOM) in patients with prostate cancer.

PURPOSE: Based on previous studies that demonstrated the safety profile and preliminary clinical activity of prostate specific antigen (PSA) targeted therapeutic vaccines, as well as recent laboratory data supporting the value of the addition of co-stimulatory molecules B7-1, ICAM-1, and LFA-3 (designated TRICOM) to these vaccines, we conducted a Phase I study to evaluate the safety and immunogenicity of a novel vaccinia and fowlpox vaccine incorporating the PSA gene sequence and TRICOM. METHODS: In this study, ten patients with androgen independent prostate cancer with or without metastatic disease were enrolled. Patients were treated with 2 x l0(8) pfu of a recombinant vaccinia virus vaccine (PROSTVAC-V) followed by 1 x 10(9) pfu of the booster recombinant fowlpox virus (PROSTVAC-F) both with gene sequences for PSA and TRICOM. The mean age of patients enrolled in the study was 70 (range 63 to 79). The mean PSA at baseline was 434 (range 9-1424). RESULTS: There were no deaths, and no Grade 3 or 4 adverse events. The most commonly reported adverse events, regardless of causality, were injection site reactions and fatigue. One serious adverse event (SAE) occurred that was unrelated to vaccine; this patient developed progressive disease with a new sphenoid metastasis. PSA was measured at week 4 and week 8. Four patients had stable disease (with less than 25% increase in PSA) through the week 8 study period. Anti-PSA antibodies were not induced with therapy: however, anti-vaccinia titers increased in all patients. CONCLUSION: This study demonstrated that vaccination with PROSTVAC-V and PROSTVAC-F combined with TRICOM is well-tolerated and generated an immune response to vaccinia. Therefore, PROSTVAC-VF/TRICOM represents a feasible therapeutic approach for further phase II and III study in patients with prostate cancer.

Therapeutic strategies for localized prostate cancer.

Prostate-specific antigen determinations for prostate cancer screening have led to a dramatic increase in the number of men who are diagnosed with organ-confined and therefore potentially curable prostate cancer. Advances in predicting outcomes with artificial neural networks may help to recommend one therapy over another. Less invasive forms of treatment, such as high-intensity focused ultrasound, may ultimately give patients additional options for treatment. Furthermore, attempts to better define the role of both neoadjuvant hormonal therapy and chemotherapy may give higher-risk patients better outcomes than with current treatments. These advances as well as continued research will likely lead to a day when more and more men with organ-confined disease will be cured.

Androgen deprivation and other treatments for advanced prostate cancer.

Among the issues discussed at this year's meeting on prostate cancer in Vail, Colorado, were several that specifically relate to the patient with advanced disease. Dr. E. David Crawford addressed the issue of the timing of hormone therapy, specifically reviewing several important trials that give a glimpse at the potential outcome of aggressive treatment in stage D1.5. The efficacy of antiandrogens, flutamide, bicalutamide, and nilutamide, when combined with chemical or surgical castration, was reviewed. Dr. Arturo Mendoza-Valdes reviewed the rationale behind intermittent (versus continuous) total androgen blockade, especially as related to quality of life. Dr. Paul Miller gave an update on the role of bisphosphonates as adjuvant therapy for prostate cancer. Also discussed was an important new agent for androgen deprivation, Abarelix, a sustained-release GnRH antagonist with low histamine-releasing potential which avoids testosterone and other hormone surge and flare.

Which patients with newly diagnosed prostate cancer need a radionuclide bone scan? An analysis based on 631 patients.

PURPOSE: Although radionuclide bone scans are frequently recommended as part of the staging evaluation for newly diagnosed prostate cancer, most scans are negative for metastases. We hypothesized that Gleason score, prostate-specific antigen (PSA), and clinical stage could predict for a positive bone scan (BS), and that a low-risk group of patients could be identified in whom BS might be omitted. METHODS: All patients who had both pathologic review of their prostate cancer biopsies and radionuclide BS at our institution between 1/90 and 5/96 were studied. Gleason score, PSA, and clinical stage (AJCC, 4th edition) were evaluated by univariate and multivariate analyses for their ability to predict a positive BS. Groups analyzed were Gleason of 2-6 vs. 7 vs. 8-10; PSA of 0-15 vs. greater than 15-50 vs. greater than 50; and clinical stage of T1a-T2b vs. T2c-T4. Univariate analysis using chi(2) and multivariate analysis using logistic regression were performed. RESULTS: Of the 631 consecutive patients, 88 (14%) had positive BS. Multivariate analysis (64 excluded due to missing PSA and/or clinical stage) showed Gleason score, PSA, and clinical stage to be significant independent predictors for positive BS (p < 0.002, p < 0.001, p < 0.001, respectively). The odds ratios were 5.25 (confidence interval [CI], 3.43-8.04) for PSA > 50 vs. 0-15; 2.25 (CI, 1.43-3.54) for Gleason of 8-10 vs. 2-6; 2.15 (CI, 1.54-2.99) for clinical stage T2c-T4 vs. T2b or less. Three of 308 (1%) had a positive BS in patients with Gleason 2-7, PSA of 50 or less, and clinical stage of T2b or less. In the subset of the same risk group with PSA of 15 or less, all 237 had negative bone scans. In patients with PSA greater than 50, 49/99(49.5%) had positive BS. CONCLUSION: Gleason score, PSA, and clinical stage were independent predictors for a positive radionuclide BS in newly diagnosed prostate cancer patients. PSA is the major predictor for positive BS. About one-half of the patients analyzed were in the low-risk group (Gleason 2-7, PSA < or = 50, clinical stage < or = T2b) and elimination of BS in these patients would result in considerable economic savings.

Southwest Oncology Group Study of paclitaxel and carboplatin for advanced transitional-cell carcinoma: the importance of survival as a clinical trial end point.

PURPOSE: The combination of paclitaxel and carboplatin for the treatment of advanced transitional-cell carcinoma (TCC) of the urothelium has promising activity and acceptable toxicity. The purpose of this trial was to evaluate the efficacy of this regimen in a cooperative group setting. PATIENTS AND METHODS: Twenty-nine patients with advanced TCC were treated every 21 days with paclitaxel 200 mg/m(2), administered as a 3-hour infusion, followed by carboplatin dosed to an area under the curve of 5. Prior systemic adjuvant or neoadjuvant platinum-based therapy was not permitted unless completed at least 1 year before enrollment. Patients were evaluated for response every three cycles, and follow-up was conducted to determine survival. RESULTS: Twenty-nine patients were enrolled and were assessable. Four (14%) had received prior adjuvant or neoadjuvant therapy. Node-only disease was present in 24%, and 76% of patients had extranodal disease. The median number of cycles received was five. Grade 4 toxicity consisted primarily of neutropenia (38% of patients). Neurologic toxicity was noted in 16 patients (grade 1 in four patients, grade 2 in five patients, grade 3 in six patients, and grade 4 in one patient). Six partial responses and no complete responses were noted, for a response proportion of 20.7% (95% confidence interval, 8% to 40%). Median progression-free survival time was 4 months, and overall survival time was 9 months. CONCLUSION: The combination of paclitaxel and carboplatin for the treatment of advanced TCC is reasonably well tolerated. However, a response proportion considerably lower than that previously reported was noted. In addition, the median survival time of 9 months was less than the survival time previously reported for patients treated with the combination of methotrexate, vinblastine, doxorubicin, and cisplatin. Although our results may reflect enrollment of patients with poor prognostic features, they also call into question the utility of this regimen.

Rapid in vivo monitoring of chemotherapeutic response using weighted sodium magnetic resonance imaging.

A novel pulse sequence strategy uses sodium magnetic resonance imaging to monitor the response to chemotherapy of mouse xenograft tumors propagated from human prostate cancer cell lines. An inversion pulse suppresses sodium with long longitudinal relaxation times, weighting the image toward intracellular sodium nuclei. Comparing these weighted sodium images before and 24 h after administration of antineoplastics, we measured a 36 +/- 4% (P < 0.001; n = 16) increase in signal intensity. Experiments with these same drugs and cells, treated in culture, detected a significant intracellular sodium elevation (10-20 mM) using a ratiometric fluorescent dye. Flow cytometry studies showed that this elevation preceded cell death by apoptosis, as determined by fluorescent end-labeling of apoptotic nuclei or Annexin V binding. Histopathology on formalin-fixed sections of explanted tumors confirmed that drug administration reduces proliferation (2.2 versus 8.6 mitotic figures per high power field; P < 0.0001), an effect that inversely correlates with the sodium magnetic resonance image response on a tumor-to-tumor basis (P < 0.02; n = 10). Morphological features, such as central zones of nonviable cells, rims of active apoptosis, and areas of viable tumor, could be distinguished by comparing weighted and unweighted images. Advantages of this sodium imaging technique include rapid determination of drug efficacy, improved diagnosis of lesions, ease of coregistration with high resolution proton magnetic resonance imaging, and absence of costly or toxic reagents.

Docetaxel (Taxotere) in hormone-refractory prostate cancer.

Considerations of both molecular biology and data from in vitro studies suggest a potential for the combination of docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) with estramustine in the treatment of patients with hormone-refractory prostate cancer. Based on data from two phase I studies, the docetaxel dose recommended for phase II study in combination with estramustine in minimally and extensively pretreated patients is 70 mg/m2 and 60 mg/m2, respectively. The dose-limiting toxicity was neutropenia. In one phase I study, 63% of the 34 patients treated showed at least a 50% decline in prostate-specific antigen. An objective response was seen in 28% of patients with measurable disease, and overall median survival (22.8 months) is highly encouraging. In the second study, 82% of 17 patients showed a greater than 50% decline in prostate-specific antigen and, at the 70 mg/m2 dose level, two of six patients showed prostate-specific antigen normalization. Phase II studies have demonstrated more than 50% declines in 59% to 88% of patients treated at 70 mg/m2. Although reduction of the dose of estramustine appears to result in a somewhat lower response rate, the contribution made by estramustine to the efficacy of the estramustine/docetaxel combination must be established by randomized trials. Dexamethasone, however, does not appear to significantly contribute to the response rate of estramustine and docetaxel. Phase III studies comparing docetaxel plus estramustine with mitoxantrone plus corticosteroids are currently being planned. If the promise of docetaxel hormone-refractory prostate cancer is realized, it may be appropriate to design clinical trials that evaluate docetaxel-based regimens as adjuvant therapy in patients who are at a high risk for relapse after definitive local therapy.