Deep and Durable Prostate-specific Antigen Response to Darolutamide with Androgen Deprivation Therapy and Docetaxel, and Association with Clinical Outcomes for Patients with High- or Low-volume Metastatic Hormone-sensitive Prostate Cancer: Analyses of the Randomized Phase 3 ARASENS Study.

BACKGROUND AND OBJECTIVE: Addition of darolutamide to androgen deprivation therapy (ADT) and docetaxel significantly improved overall survival (OS) in ARASENS (NCT02799602). Here we report on prostate-specific antigen (PSA) responses and their association with outcomes. METHODS: ARASENS is an international, double-blind, phase 3 study in patients with metastatic hormone-sensitive prostate cancer (mHSPC) randomized to darolutamide 600 mg orally twice daily (n = 651) or placebo (n = 654), both with ADT + docetaxel. The proportion of patients with undetectable PSA (<0.2 ng/ml) and time to PSA progression (≥25% relative and ≥2 ng/ml absolute increase from nadir) were compared between groups in prespecified exploratory analyses. PSA outcomes by disease volume and the association of undetectable PSA with OS and times to castration-resistant prostate cancer (CRPC) and PSA progression were assessed in post hoc analyses. KEY FINDINGS AND LIMITATIONS: The proportion of patients with undetectable PSA at any time was more than doubled with darolutamide versus placebo, at 67% versus 29% in the overall population, 62% versus 26% in the high-volume subgroup, and 84% versus 38% in the low-volume subgroup. Darolutamide delayed time to PSA progression versus placebo, with hazard ratios of 0.26 (95% confidence interval [CI] 0.21-0.31) in the overall population, 0.30 (95% CI 0.24-0.37) in the high-volume subgroup, and 0.093 (95% CI 0.047-0.18) in the low-volume subgroup. Undetectable PSA at 24 wk was associated with longer OS, with a hazard ratio of 0.49 (95% CI 0.37-0.65) in the darolutamide group, as well as longer times to CRPC and PSA progression, with similar findings in the disease volume subgroups. CONCLUSIONS AND CLINICAL IMPLICATIONS: Darolutamide + ADT + docetaxel led to deep and durable PSA responses in patients with high- or low-volume mHSPC. Achievement of undetectable PSA (<0.2 ng/ml) was correlated with better clinical outcomes. PATIENT SUMMARY: For patients with metastatic hormone-sensitive prostate cancer being treated with androgen deprivation therapy and docetaxel, PSA (prostate-specific antigen) became undetectable (below 0.2 ng/ml) in 67% of those also receiving darolutamide versus 29% of patients also receiving placebo. On average, patients achieving undetectable PSA lived longer than patients with detectable PSA.

Pembrolizumab plus Olaparib in Patients with Metastatic Castration-resistant Prostate Cancer: Long-term Results from the Phase 1b/2 KEYNOTE-365 Cohort A Study.

BACKGROUND: Pembrolizumab and olaparib have shown single-agent activity in patients with previously treated metastatic castration-resistant prostate cancer (mCRPC). OBJECTIVE: To evaluate the efficacy and safety of pembrolizumab plus olaparib in mCRPC. DESIGN, SETTING, AND PARTICIPANTS: Cohort A of the phase 1b/2 KEYNOTE-365 study enrolled patients with molecularly unselected, docetaxel-pretreated mCRPC whose disease progressed within 6 mo of screening. INTERVENTION: Pembrolizumab 200 mg intravenously every 3 wk plus olaparib 400-mg capsule or 300-mg tablet orally twice daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoints were safety, confirmed prostate-specific antigen (PSA) response rate, and objective response rate (ORR) as per Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, by blinded independent central review. The secondary endpoints included radiographic progression-free survival (rPFS) and overall survival (OS). RESULTS AND LIMITATIONS: Of 104 enrolled patients, 102 were treated. The median age was 70 yr (interquartile range [IQR], 65-76), and 59 patients (58%) had measurable disease as per RECIST v1.1. The median time from the first dose to database cutoff was 24 mo (IQR, 22-47). The confirmed PSA response rate was 15%. The confirmed ORR was 8.5% (five partial responses) for patients with measurable disease. The median rPFS was 4.5 mo (95% confidence interval [CI], 4.0-6.5) and median OS was 14 mo (95% CI, 10.4-18.2). Clinical activity was consistent across the programmed death ligand 1 (PD-L1)-positive and homologous recombination repair mutation subgroups. Treatment-related adverse events (TRAEs) occurred in 93 patients (91%). Grade 3-5 TRAEs occurred in 49 patients (48%). Six deaths (5.9%) were due to adverse events; two (myocardial infarction and unknown cause) were attributed to treatment. Limitations of the study include the single-arm design. CONCLUSIONS: Pembrolizumab plus olaparib had a safety profile consistent with the profiles of the individual agents and demonstrated antitumor activity in previously treated patients with molecularly unselected, docetaxel-pretreated mCRPC. PATIENT SUMMARY: Pembrolizumab plus olaparib showed antitumor activity and expected safety in patients with metastatic castration-resistant prostate cancer.

Lutetium-177-PSMA-617 for Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Metastatic castration-resistant prostate cancer remains fatal despite recent advances. Prostate-specific membrane antigen (PSMA) is highly expressed in metastatic castration-resistant prostate cancer. Lutetium-177 (177Lu)-PSMA-617 is a radioligand therapy that delivers beta-particle radiation to PSMA-expressing cells and the surrounding microenvironment. METHODS: We conducted an international, open-label, phase 3 trial evaluating 177Lu-PSMA-617 in patients who had metastatic castration-resistant prostate cancer previously treated with at least one androgen-receptor-pathway inhibitor and one or two taxane regimens and who had PSMA-positive gallium-68 (68Ga)-labeled PSMA-11 positron-emission tomographic-computed tomographic scans. Patients were randomly assigned in a 2:1 ratio to receive either 177Lu-PSMA-617 (7.4 GBq every 6 weeks for four to six cycles) plus protocol-permitted standard care or standard care alone. Protocol-permitted standard care excluded chemotherapy, immunotherapy, radium-223 (223Ra), and investigational drugs. The alternate primary end points were imaging-based progression-free survival and overall survival, which were powered for hazard ratios of 0.67 and 0.73, respectively. Key secondary end points were objective response, disease control, and time to symptomatic skeletal events. Adverse events during treatment were those occurring no more than 30 days after the last dose and before subsequent anticancer treatment. RESULTS: From June 2018 to mid-October 2019, a total of 831 of 1179 screened patients underwent randomization. The baseline characteristics of the patients were balanced between the groups. The median follow-up was 20.9 months. 177Lu-PSMA-617 plus standard care significantly prolonged, as compared with standard care, both imaging-based progression-free survival (median, 8.7 vs. 3.4 months; hazard ratio for progression or death, 0.40; 99.2% confidence interval [CI], 0.29 to 0.57; P<0.001) and overall survival (median, 15.3 vs. 11.3 months; hazard ratio for death, 0.62; 95% CI, 0.52 to 0.74; P<0.001). All the key secondary end points significantly favored 177Lu-PSMA-617. The incidence of adverse events of grade 3 or above was higher with 177Lu-PSMA-617 than without (52.7% vs. 38.0%), but quality of life was not adversely affected. CONCLUSIONS: Radioligand therapy with 177Lu-PSMA-617 prolonged imaging-based progression-free survival and overall survival when added to standard care in patients with advanced PSMA-positive metastatic castration-resistant prostate cancer. (Funded by Endocyte, a Novartis company; VISION ClinicalTrials.gov number, NCT03511664.).

Real-world outcomes of sipuleucel-T treatment in PROCEED, a prospective registry of men with metastatic castration-resistant prostate cancer.

BACKGROUND: The large registry, PROVENGE Registry for the Observation, Collection, and Evaluation of Experience Data (PROCEED)(NCT01306890), evaluated sipuleucel-T immunotherapy for asymptomatic/minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). METHODS: PROCEED enrolled patients with mCRPC receiving 3 biweekly sipuleucel-T infusions. Assessments included overall survival (OS), serious adverse events (SAEs), cerebrovascular events (CVEs), and anticancer interventions (ACIs). Follow-up was for ≥3 years or until death or study withdrawal. RESULTS: In 2011-2017, 1976 patients were followed for 46.6 months (median). The median age was 72 years, and the baseline median prostate-specific antigen level was 15.0 ng/mL; 86.7% were white, and 11.6% were African American. Among the patients, 1902 had 1 or more sipuleucel-T infusions. The median OS was 30.7 months (95% confidence interval [CI], 28.6-32.2 months). Known prognostic factors were independently associated with OS in a multivariable analysis. Among the 1255 patients who died, 964 (76.8%) died of prostate cancer (PC) progression. The median time from the first infusion to PC death was 42.7 months (95% CI, 39.4-46.2 months). The incidence of sipuleucel-T-related SAEs was 3.9%. The incidence of CVEs was 2.8%, and the rate per 100 person-years was 1.2 (95% CI, 0.9-1.6). The CVE incidence among 11,972 patients with mCRPC from the Surveillance, Epidemiology, and End Results-Medicare database was 2.8%; the rate per 100 person-years was 1.5 (95% CI, 1.4-1.7). One or more ACIs (abiraterone, enzalutamide, docetaxel, cabazitaxel, or radium 223) were received by 77.1% of the patients after sipuleucel-T; 32.5% and 17.4% of the patients experienced 1- and 2-year treatment-free intervals, respectively. CONCLUSIONS: PROCEED provides contemporary survival data for sipuleucel-T-treated men in a real-world setting of new life-prolonging agents, which will be useful in discussing treatment options with patients and in powering future trials with sipuleucel-T. The safety and tolerability of sipuleucel-T in PROCEED were consistent with previous findings.

Re-treatment with radium-223: 2-year follow-up from an international, open-label, phase 1/2 study in patients with castration-resistant prostate cancer and bone metastases.

BACKGROUND: Radium-223 dichloride (radium-223) is approved for patients with castration-resistant prostate cancer (CRPC), symptomatic bone metastases, and no visceral disease using a dosing regimen of 6 injections (55 kBq/kg intravenously; 1 injection every 4 weeks). Early results from international, open-label, phase 1/2 study NCT01934790 showed that re-treatment with radium-223 was well tolerated with favorable effects on disease progression. Here we report safety and efficacy findings from 2-year follow-up of the radium-223 re-treatment study. METHODS: Patients with CRPC and bone metastases who completed 6 initial radium-223 injections with no disease progression in bone and later progressed were eligible for radium-223 re-treatment (up to 6 additional radium-223 injections), provided that hematologic parameters were adequate and chemotherapy had not been administered after the initial course of radium-223. Concomitant cytotoxic agents were not allowed during re-treatment but were allowed at the investigator's discretion during follow-up; other concomitant agents for prostate cancer (including abiraterone acetate or enzalutamide) were allowed at investigator's discretion. The primary objective was safety. Exploratory objectives included time to radiographic bone progression, radiographic progression-free survival (rPFS), time to total alkaline phosphatase (tALP), and prostate-specific antigen (PSA) progression, overall survival (OS), time to first symptomatic skeletal event (SSE), and SSE-free survival, all calculated from re-treatment start. Evaluation of safety and exploratory efficacy objectives included active 2-year follow-up. Safety results from active follow-up and updated efficacy are reported. RESULTS: Overall, 44 patients were re-treated with radium-223; 29 (66%) completed all 6 injections, and 34 (77%) entered 2-year active follow-up, during which no new safety concerns and no serious drug-related adverse events were noted. rPFS events (progression or death) occurred in 19 (43%) of 44 patients; median rPFS was 9.9 months. Radiographic bone progression occurred in 5 (11%) of 44 patients. Median OS was 24.4 months. Median times to first SSE and SSE-free survival were 16.7 and 12.8 months, respectively. Median time to tALP progression was not reached; median time to PSA progression was 2.2 months. CONCLUSIONS: Re-treatment with radium-223 in this selected patient population was well tolerated, led to minimal hematologic toxicity, and provided continued disease control in bone at 2-year follow-up.

Phase I Study of Seviteronel, a Selective CYP17 Lyase and Androgen Receptor Inhibitor, in Men with Castration-Resistant Prostate Cancer.

Purpose: Seviteronel (INO-464) is a selective cytochrome P450c17a (CYP17) 17,20-lyase (lyase) and androgen receptor (AR) inhibitor with antitumor activity in vitro and in vivo This open-label phase I clinical study evaluated the safety, tolerability, pharmacokinetics and activity of once-daily seviteronel in male chemotherapy-naïve subjects with castration-resistant prostate cancer (CRPC).Patients and Methods: Seviteronel was administered at 600 mg once daily with dose titration (DT) and in modified 3 + 3 dose escalation once-daily cohorts at 600, 750, and 900 mg without DT. The primary objectives of this study were to establish safety, tolerability, and the MTD of seviteronel in chemotherapy-naïve subjects with or without prior treatment with FDA-approved CRPC treatments, abiraterone acetate (AA), and enzalutamide. Secondary objectives were to assess pharmacokinetics, PSA, tumor response, and endocrine results.Results: Twenty-one subjects were enrolled. No dose-limiting toxicities (DLT) were observed through 750 mg once daily. Most treatment-emergent adverse events (AE) reported at grade 1-2. The most commonly reported AEs were fatigue (71%), dizziness (52%), blurred vision (38%), and dysgeusia (33%), with most AEs improving after dose reduction or dose interruption.Conclusions: Once-daily seviteronel was generally well tolerated in this phase I study of men with CRPC, a majority of which had progressed on prior AA or enzalutamide, or both. Of the doses evaluated, 600 mg once daily was chosen as the recommended phase II dose for future studies in subjects with CRPC. Clin Cancer Res; 24(21); 5225-32. ©2018 AACR.

eRADicAte: A Prospective Evaluation Combining Radium-223 Dichloride and Abiraterone Acetate Plus Prednisone in Patients With Castration-Resistant Prostate Cancer.

BACKGROUND: Multiple castration-resistant prostate cancer (CRPC) therapies are approved by the United States Food and Drug Administration. Radium-223 dichloride (Ra-223) with abiraterone acetate plus prednisone have different mechanisms of action and distinct off-target side-effect profiles. We prospectively investigated their combined safety, tolerability, and patient-reported outcome measures. PATIENTS AND METHODS: eRADicAte, an investigator-initiated, phase II trial, studied 31 patients with metastatic CRPC, from 5 United States uro-oncology research sites. Patients completed 6 cycles of Ra-223 with concurrent abiraterone therapy. Quality of life and pain were assessed using the Functional Assessment of Cancer Therapy-Prostate and the Brief Pain Inventory-Short Form questionnaires and their subscales; we reported the number of subjects meeting standardized criteria for clinically meaningful improvements on each scale. Safety assessment included Eastern Cooperative Oncology Group performance status, laboratory changes, opioid use, radiographic responses, and adverse events (AEs). RESULTS: Twenty of 31 (65%) experienced positive clinically meaningful improvement changes on the Functional Assessment of Cancer Therapy-Prostate, and 25 (81%) of 31 on the Prostate Cancer Subscale. Eighteen (58%) of 31 demonstrated reduced pain intensity and 12 (39%) of 31 demonstrated reduction of pain interference in their lives. At baseline, subjects averaged 11.6 ± 2.8 bone lesions; at the end of treatment, subjects averaged 5.6 ± 2.4 bone lesions (P = .0002). The most frequent AEs were diarrhea (17%), nausea (17%), and fatigue (14%). There were 6 serious AEs; 1 led to study withdrawal. CONCLUSIONS: Patients experienced clinically meaningful improvements in quality of life and pain, without unexpected adverse toxicities. Phase III combination trials of Ra-223 with novel oral hormonal agents are ongoing to further evaluate radiographic progression and overall survival benefit.

Androgen Receptor Modulation Optimized for Response (ARMOR) Phase I and II Studies: Galeterone for the Treatment of Castration-Resistant Prostate Cancer.

PURPOSE: Galeterone is a selective, multitargeted agent that inhibits CYP17, antagonizes the androgen receptor (AR), and reduces AR expression in prostate cancer cells by causing an increase in AR protein degradation. These open-label phase I and II studies [Androgen Receptor Modulation Optimized for Response-1 (ARMOR1) and ARMOR2 part 1] evaluated the efficacy and safety of galeterone in patients with treatment-naive nonmetastatic or metastatic castration-resistant prostate cancer (CRPC) and established a dose for further study. EXPERIMENTAL DESIGN: In ARMOR1, 49 patients received increasing doses (650-2,600 mg) of galeterone in capsule formulation; 28 patients in ARMOR2 part 1 received increasing doses (1,700-3,400 mg) of galeterone in tablet formulation for 12 weeks. Patients were evaluated biweekly for safety and efficacy, and pharmacokinetic parameters were assessed. RESULTS: In ARMOR1, across all doses, 49.0% (24/49) achieved a ≥30% decline in prostate-specific antigen (PSA; PSA30) and 22.4% (11/49) demonstrated a ≥50% PSA decline (PSA50). In ARMOR2 part 1, across all doses, PSA30 was 64.0% (16/25) and PSA50 was 48.0% (12/25). In the 2,550-mg dose cohort, PSA30 was 72.7% (8/11) and PSA50 was 54.5% (6/11). Galeterone was well tolerated; the most common adverse events were fatigue, increased liver enzymes, gastrointestinal events, and pruritus. Most were mild or moderate in severity and required no action and there were no apparent mineralocorticoid excess (AME) events. CONCLUSIONS: The efficacy and safety from ARMOR1 and ARMOR2 part 1 and the pharmacokinetic results support the galeterone tablet dose of 2,550 mg/d for further study. Galeterone was well tolerated and demonstrated pharmacodynamic changes consistent with its selective, multifunctional AR signaling inhibition.

Intermittent Chemotherapy as a Platform for Testing Novel Agents in Patients With Metastatic Castration-Resistant Prostate Cancer: A Department of Defense Prostate Cancer Clinical Trials Consortium Randomized Phase II Trial of Intermittent Docetaxel With Prednisone With or Without Maintenance GM-CSF.

BACKGROUND: Immunotherapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), an agent that previously demonstrated antitumor activity, was evaluated within an intermittent chemotherapy framework of docetaxel with prednisone (D+P) in metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: mCRPC patients with ≥ 50% prostate-specific antigen (PSA) decline after 6 cycles of D+P were randomized to either GM-CSF or observation (Obs). At disease progression (PD), D+P was reinitiated for 6 cycles followed by the same "off chemotherapy" regimen in patients eligible for chemotherapy interruption. The sequence was repeated until PD during chemotherapy, lack of PSA response to chemotherapy, or unacceptable toxicity. The primary end point was time to chemotherapy resistance (TTCR). RESULTS: Of 125 patients enrolled, 52 (42%) experienced ≥ 50% PSA decline on induction D+P and were randomized to GM-CSF (n = 27) or Obs (n = 25). The median time to PD was 3.3 months (95% confidence interval [CI], 2.4-3.5) and 1.5 months (95% CI, 1.5-2.4) during the initial course of GM-CSF and Obs, respectively. Twelve of 26 (46%) patients responded to a second course of D+P. Eleven randomized patients (21%) experienced PD during chemotherapy, precluding accurate assessment of TTCR. The remaining 41 randomized patients discontinued study for lack of PSA response to chemotherapy (n = 8), patient choice to not restart chemotherapy with PSA PD (n = 13), toxicity (n = 7), or study withdrawal (n = 13). CONCLUSION: Conducting a prospective study in mCRPC with maintenance immunotherapy within the framework of intermittent chemotherapy was feasible. The use of PSA instead of radiographic end points limited the number of evaluable patients. This study provides important insight into designing contemporary intermittent chemotherapy trials with maintenance immunotherapy in patients with advanced prostate cancer.

Randomized, open-label phase III trial of docetaxel plus high-dose calcitriol versus docetaxel plus prednisone for patients with castration-resistant prostate cancer.

PURPOSE: To compare the efficacy and safety of docetaxel plus high-dose calcitriol (DN-101) to docetaxel plus prednisone in an open-label phase III trial. PATIENTS AND METHODS: Nine hundred fifty-three men with metastatic castration-resistant prostate cancer (CRPC) were randomly assigned to Androgen-Independent Prostate Cancer Study of Calcitriol Enhancing Taxotere (ASCENT; 45 µg DN-101, 36 mg/m(2) docetaxel, and 24 mg dexamethasone weekly for 3 of every 4 weeks) or control (5 mg prednisone twice daily with 75 mg/m(2) docetaxel and 24 mg dexamethasone every 3 weeks) arms. The primary end point was overall survival (OS), assessed by the Kaplan-Meier method. RESULTS: At an interim analysis, more deaths were noted in the ASCENT arm, and the trial was halted. The median-follow-up for patients alive at last assessment was 11.7 months. Median OS was 17.8 months (95% CI, 16.0 to 19.5) in the ASCENT arm and 20.2 months (95% CI, 18.8 to 23.0) in the control arm (log-rank P = .002). Survival remained inferior after adjusting for baseline variables (hazard ratio, 1.33; P = .019). The two arms were similar in rates of total and serious adverse events. The most frequent adverse events were GI (reported in 75% of patients), and blood and lymphatic disorders (48%). Docetaxel toxicity leading to dose modification was more frequent in the ASCENT (31%) than in the control arm (15%). CONCLUSION: ASCENT treatment was associated with shorter survival than the control. This difference might be due to either weekly docetaxel dosing, which, in a prior study, showed a trend toward inferior survival compared with an every-3-weeks regimen, or DN-101 therapy.

Improved survival in never-smokers vs current smokers with primary adenocarcinoma of the lung.

STUDY OBJECTIVES: Adenocarcinoma of the lung is now the most common histologic subtype of lung cancer in the United States. To determine if there are survival differences in never-smokers and current smokers with adenocarcinoma, we conducted an analysis of lung adenocarcinomas seen at the H. Lee Moffitt Cancer Center, and looked for demographic and survival differences in the two groups. DESIGN: Data were gathered through the tumor registry at the H. Lee Moffitt Cancer Center and confirmed by chart review. A total of 132 documented never-smokers and 522 current smokers with lung adenocarcinoma were included. Detailed demographic survival information were gathered and tabulated. Former smokers were not included in the study. Multivariate analyses were performed using the Cox regression method to identify variables with independent prognostic significance. Life table actuarial analyses were performed to determine survival. Differences between survival curves were estimated using the log-rank test. RESULTS: The mean age at diagnosis for never-smokers was higher as compared to current smokers: 63.5 years vs 59.4 years (p = 0.0005). In addition, there was an increased percentage of female subjects in the never-smoker category: 78% vs 54% (p < 0.0001). There was a statistically significant difference in survival between current smokers and never-smokers (p = 0.004). The Kaplan-Meier estimates at 5 years were 16% for current smokers and 23% for never-smokers. On multivariate analyses, smoking was identified as an independent negative prognostic factor. CONCLUSION: Our data show that never-smokers with adenocarcinoma are predominantly female, present at a higher mean age, and have improved survival when compared to current smokers. By multivariate analyses, the never-smoking status was found to be an independent predictor of improved survival. The survival difference may be partly influenced by less comorbidity among never-smokers. Nevertheless, owing to differences in the mechanism of carcinogenesis (in smokers vs nonsmokers), demographic factors, tumor behavior and survival, adenocarcinomas occurring in never-smokers may display a distinct natural history and may warrant further investigation as a separate entity with epidemiologic studies and clinical trials designed specifically for this category of non-small cell lung cancer.

DNA vaccines: an active immunization strategy for prostate cancer.

Immunotherapy is currently being investigated as a treatment for patients with asymptomatic, recurrent prostate cancer manifested only by a rising prostate-specific antigen (PSA) level. Several different approaches to active immunization against antigens found on cancer cells have been explored. Immunization with DNA overcomes many of the obstacles noted in previous studies. Injection of plasmid DNA encoding a xenogeneic differentiation antigen (prostate-specific membrane antigen [PSMA]) is a potent means to induce antibody and T-cell responses to these otherwise poorly immunogenic self proteins. Use of the xenogeneic DNA (ie, human PSMA DNA injected into mouse) has been shown to be an absolute requirement to overcome immunologic tolerance. We are currently conducting a phase I trial of human and mouse PSMA DNA vaccines in patients with recurrent prostate cancer, based on preclinical experiments described below.