Pagliaro, Lance C.

e17036 Background: Elevated serum CGA is associated with an intrinsic or treatment-related neuroendocrine differentiation in men with mCRPC. We previously demonstrated that elevated serum CGA was negatively associated with OS in men with mCRPC. Fluctuations in serum CGA during mCRPC therapy is not well known. We analyzed the impact of (i) rising serum CGA and (ii) baseline CGA/PSA ratio during treatment to identify associations with AA therapy. Methods: Between June 2013 and August 2015, 92 men with mCRPC were enrolled in a prospective trial (“PROMOTE”; NCT#01953640) with uniform serum processing performed prior to initiating abiraterone acetate/prednisone (AA/P) and serially after 12 weeks of AA/P treatments. Serum CGA was measured using a homogenous automated immunofluorescent assay. Patients (pts) receiving proton pump inhibitors or with abnormal renal function were excluded due to possible false elevations of serum CGA (n = 21 excluded). All patients underwent a composite response assessment at 12-weeks with imaging/PSA/QOL questionnaires. Kaplan Meier estimates, and Cox Regression models were used to calculate association with time-to-treatment failure (TTF) analyses, defined as time from treatment initiation to AA/P discontinuation based on disease progression (BlueSky Statistics, Chicago, IL, USA). Results: Of the 71 eligible pts, 67/71 had paired baseline and 12-week CGA and 70/71 pts had a baseline and a 12-week PSA available. The median baseline CGA was 83.0ng/ml (range: 53.0 - 127.0 ng/ml), median baseline PSA was 14.4 ng/ml (range: 6.4-40.2 ng/ml), and the median TTF was 10 months (range: 6-25 months). The median CGA after 12 weeks of AA/P was 98.0 ng/ml (58.0 -148.0 ng/ml) and we observed a CGA rise in 41/67 (61.2%) pts. An increase in chromogranin was associated with a lower risk of treatment failure (HR: 0.52, p = 0.0181). The median CGA/PSA ratio was 7.8 (2.6 -16.0). An elevated pretreatment CGA/PSA ratio above the median was associated with a lower risk of treatment failure (HR: 0.54 p value = 0.0185). Conclusions: We show that an increasing chromogranin on AA/P and an elevated baseline CGA/PSA in pts with mCRPC were associated with a favorable response to AA/P. Further studies are needed to assess if rising CGA during therapy reflects neuroendocrine differentiation and may indicate a sign of treatment effect targeting the androgen susceptible cells. Clinical trial information: NCT#01953640.

TPS7 Background: Penis cancer is a rare but potentially fatal disease. A limited body of evidence exists on which to base the majority of management decisions for patients with regional nodal metastases. Five-year survival for patients with a single involved inguinal lymph node treated with surgery alone is approximately 80%, whilst it ranges from 0 to 12% for patients with pelvic node involvement (N3). Additional strategies are required for the management regionally-advanced disease. InPACT (NCT02305654) aims to determine prospectively the relative benefits and sequencing of surgery, chemotherapy, and chemoradiotherapy in the management of patients with penis cancer who present with palpable or radiologically evident inguinal lymph node metastases. InPACT addresses the following questions: Is there a role for neoadjuvant therapy and, if so, which of the two options (chemotherapy or chemoradiotherapy) before surgery gives superior outcomes? Among patients whose inguinal node histology predicts a high risk of recurrence, does prophylactic pelvic lymph node dissection (PLND) plus chemoradiation to the inguinal and pelvic fields improve survival compared to chemoradiation alone? Methods: A Bayesian trial design aims to include a wide population of patients and incorporates two randomisations: InPACT-neoadjuvant and InPACT-pelvis. Participants are stratified by disease burden (extent of nodal involvement), by the presence or absence of high-risk radiological features, and by GFR. Participants with high disease burden where neoadjuvant treatment is thought to be indicated are randomised to neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy. Participants with intermediate disease burden are randomised to one of 3 arms: Surgery alone or neoadjuvant chemoradiotherapy followed by surgery, or neoadjuvant chemotherapy prior to surgery. Participants in the low-burden group proceed directly to surgery. Participants with postoperative inguinal node pathology that shows high-risk features may then proceed to InPACT-pelvis where randomisation is between adjuvant chemoradiotherapy ± PLND for those not previously treated with chemoradiotherapy & between PLND & observation for those previously treated with neoadjuvant chemoradiotherapy. The study aims to recruit 200 participants. The primary outcome measure is overall survival, with secondary outcome measures of disease-specific survival, disease-free survival, and freedom from locoregional recurrence and distant metastasis. Feasibility, toxicity, the type/extent of surgical complications, and quality of life will be assessed as secondary endpoints for all the InPACT treatment arms. To October 2021, 65 participants have been recruited with centres open in the UK, US and Canada. Clinical trial information: NCT02305654.

Abstract The second-generation antiandrogens have achieved an ever-growing list of approvals and indications in subsets of prostate cancer. Here, we provide an overview of second-generation antiandrogen trials and FDA approvals and outline a rational sequencing approach for the use of these agents as they relate to chemotherapy and other available treatment modalities in advanced prostate cancer. All published phase II-III randomized controlled trials reporting outcomes with the use of second-generation antiandrogens in prostate cancer are included as well as all published trials and retrospective studies of second-generation antiandrogen sequencing and/or combinations. Complete tabular and graphical representation of all available evidence is provided regarding the use and sequencing of second-generation antiandrogens in prostate cancer. In metastatic castration-resistant prostate cancer, evidence suggests prioritization of abiraterone before chemotherapy, chemotherapy after second-generation antiandrogen failure, and postchemotherapy enzalutamide in select patients to maximize agent efficacy and tolerability. We conclude that a rational, optimized sequencing of second-generation antiandrogens with other treatment options is feasible with present data.

Abstract Purpose: To evaluate the association between neutrophil-to-lymphocyte ratio (NLR) and efficacy of avelumab plus axitinib or sunitinib. Experimental Design: Adult patients with untreated advanced renal cell carcinoma (RCC) with a clear-cell component, ≥1 measurable lesions, Eastern Cooperative Oncology Group performance status of 0 or 1, fresh or archival tumor specimen, and adequate renal, cardiac, and hepatic function were included. Retrospective analyses of the association between baseline NLR and progression-free survival (PFS) and overall survival (OS) in the avelumab plus axitinib or sunitinib arms were performed using the first interim analysis of the phase 3 JAVELIN Renal 101 trial (NCT02684006). Multivariate Cox regression analyses of PFS and OS were conducted. Translational data were assessed to elucidate the underlying biology associated with differences in NLR. Results: Patients with below-median NLR had longer observed PFS with avelumab plus axitinib [stratified HR, 0.85; 95% confidence interval (CI), 0.634–1.153] or sunitinib (HR, 0.56; 95% CI, 0.415–0.745). In the avelumab plus axitinib or sunitinib arms, respectively, median PFS was 13.8 and 11.2 months in patients with below-median NLR, and 13.3 and 5.6 months in patients with median-or-higher NLR. Below-median NLR was also associated with longer observed OS in the avelumab plus axitinib (HR, 0.51; 95% CI, 0.300–0.871) and sunitinib arms (HR, 0.30; 95% CI, 0.174–0.511). Tumor analyses showed an association between NLR and key biological characteristics, suggesting a role of NLR in underlying mechanisms influencing clinical outcome. Conclusions: Current data support NLR as a prognostic biomarker in patients with advanced RCC receiving avelumab plus axitinib or sunitinib.

Abstract Purpose: Outcomes for resistant metastatic castration-resistant prostate cancer (CRPC) are poor. Stereotactic ablative radiotherapy (SABR) induces antitumor immunity in clinical and preclinical studies, but immunologic biomarkers are lacking. Patients and Methods: Eighty-nine patients with oligometastatic CRPC were identified by 11C-Choline-PET (Choline-PET) from August 2016 to December 2019 and treated with SABR. Prespecified coprimary endpoints were 2-year overall survival (OS) and PSA progression. Secondary endpoints included 2-year SABR-treated local failure and 6-month adverse events. Correlative studies included peripheral blood T-cell subpopulations before and after SABR. Results: 128 lesions in 89 patients were included in this analysis. Median OS was 29.3 months, and 1- and 2-year OS were 96% and 80%, respectively. PSA PFS was 40% at 1 year and 21% at 2 years. Local PFS was 84.4% and 75.3% at 1 and 2 years, respectively, and no grade ≥3 AEs were observed. Baseline high levels of tumor-reactive T cells (TTR; CD8+CD11ahigh) predicted superior local, PSA, and distant PFS. Baseline high levels of effector memory T cells (TEM; CCR7−CD45RA−) were associated with improved PSA PFS. An increase in TTR at day 14 from baseline was associated with superior OS. Conclusions: This is the first comprehensive effector T-cell immunophenotype analysis in a phase II trial before and after SABR in CRPC. Results are favorable and support the incorporation of immune-based markers in the design of future randomized trials in patients with oligometastatic CRPC treated with SABR.

AbstractIntroductionChemotherapy in combination with immunotherapy has a proven survival benefit compared to chemotherapy alone in extensive stage small cell lung cancer (SCLC) and is the new standard of care. Since extrapulmonary small cell carcinomas (SCCs) are less common, treatment paradigms are reasonably extrapolated from SCLC regimens. We examined our institution's experience utilizing the combination of chemotherapy and immunotherapy (as used in SCLC) for SCC and neuroendocrine carcinoma of the prostate.MethodsUtilizing an institutional database search tool, we queried the electronic medical record to identify patients with SCC or neuroendocrine carcinoma of the prostate who had been treated with atezolizumab and chemotherapy. We recorded patient characteristics, including age, pathology, and disease extent. Treatment characteristics included number of prior treatments, use of concominant androgen deprivation, number of cycles of immunotherapy, and prior systemic therapies (including those for adenocarcinoma of the prostate). Progression free survival (PFS) and overall survival (OS) were the primary outcomes.ResultsWe identified seven men who received atezolizumab for metastatic prostate cancer with a small cell or neuroendocrine component. In six of the seven patients, the combination of carboplatin, etoposide, and atezolizumab was the first‐line of treatment after diagnosis of small cell or neuroendocrine carcinoma. Two of the seven patients had de novo small cell/neuroendocrine pathology, while the other five had transformation from a preexisting adenocarcinoma. In the patients who received chemotherapy plus immunotherapy in the first‐line setting, at a median follow‐up of 6.5 months (range: 1.5–15.1) the median PFS was 3.4 months and median OS was 8.4 months.ConclusionSmall cell or neuroendocrine carcinoma of the prostate was associated with poor survival outcomes despite adding immunotherapy (atezolizumab) to chemotherapy (carboplatin and etoposide). To our knowledge, there has been no demonstrable benefit of adding immunotherapy to chemotherapy in this setting.

Those with metastatic urothelial carcinoma generally respond more poorly to chemotherapy after they have progression on a checkpoint inhibitor (CPI). There is interest in combining CPIs with conventional cytotoxic chemotherapies as a strategy to exploit the efficacy and immunomodulatory effects of chemotherapy. We conducted a single institution, retrospective analysis including all patients treated between May 2018 and May 2020 with carboplatin and paclitaxel, concurrently or sequential with pembrolizumab, after having progression on a CPI alone. Clinical characteristics, response by RECIST 1.1, progression-free survival, and safety/tolerance of the treatment are reported. Median age was 80 years (64–85). Five patients (100%) had visceral metastases when starting carboplatin and paclitaxel. Chemotherapy was given with concurrent pembrolizumab (four patients) or following pembrolizumab (one patient) and continued until maximum response, significant toxicity, or progression. Two patients subsequently remained on maintenance pembrolizumab. There were four partial responses and one patient with stable disease. All patients on follow-up have progressed with median time to progression of 47 weeks (18–75). Two patients died from disease progression. This case series suggests that the combination of carboplatin, paclitaxel, and pembrolizumab leads to durable freedom from progression in some with metastatic urothelial cancer, who have progressed on a CPI alone. Larger studies of chemoimmunotherapy for metastatic urothelial carcinoma are warranted.

Abstract Purpose: Men with metastatic castration-resistant prostate cancer (mCRPC) have limited treatment options after progressing on hormonal therapy and chemotherapy. Here, we evaluate the safety and efficacy of atezolizumab (anti–PD-L1) + radium-223 dichloride (radium-223) in men with mCRPC. Patients and Methods: This phase Ib study evaluated atezolizumab + radium-223 in men with mCRPC and bone and lymph node and/or visceral metastases that progressed after androgen pathway inhibitor treatment. Following safety assessment of concurrent dosing, 45 men were randomized 1:1:1 to concurrent or one of two staggered dosing schedules with either agent introduced one cycle before the other. This was followed by a safety–efficacy expansion cohort (randomized 1:1:1). The primary endpoints were safety and objective response rate (ORR) by RECIST 1.1. Secondary endpoints included radiographic progression-free survival (rPFS), PSA responses, and overall survival (OS). Results: As of October 4, 2019, 44 of 45 men were evaluable. All 44 had ≥1 all-cause adverse event (AE); 23 (52.3%) had a grade 3/4 AE. Fifteen (34.1%) grade 3/4 and 3 (6.8%) grade 5 AEs were related to atezolizumab; none were related to radium-223. Confirmed ORR was 6.8% [95% confidence interval (CI), 1.4–18.7], median rPFS was 3.0 months (95% CI, 2.8–4.6), median PSA progression was 3.0 months (95% CI, 2.8–3.3), and median OS was 16.3 months (95% CI, 10.9–22.3). Conclusions: This phase Ib study demonstrated that atezolizumab + radium-223, regardless of administration schedule, had greater toxicity than either drug alone, with no clear evidence of additional clinical benefit for patients with mCRPC and bone and lymph node and/or visceral metastases.

421 Background: Reported rates of adherence to post-radical cystectomy (RC) surveillance guidelines in real-world practice have been as low as 9%, in part reflecting a nihilistic view held by many of the value of routine follow-up. Indeed, conflicting data exist regarding the outcomes of patients with cancer recurrence detected by scheduled surveillance versus symptom-directed evaluation. Herein, we assessed comparative outcomes of patients with symptomatic recurrence (SR) versus asymptomatic recurrence (AR) after RC. Methods: We reviewed our Institutional Registry of RC patients to identify patients with cancer recurrence following RC. Presenting symptoms in the SR cohort included pain, constitutional symptoms, gastrointestinal symptoms, and hematuria/voiding symptoms, whereas AR was defined as recurrence detected on routine surveillance in the absence of symptoms. Baseline demographic and clinical characteristics were compared between study groups using chi-square and t-test. Kaplan-Meier and Cox survival analyses were performed to compare cancer-specific survival (CSS) and overall survival (OS) between AR and SR groups. Results: Of 3822 patients who underwent RC from 1980-2018 (with a median follow-up after RC of 2.4 years (IQR 1.1,5.5), a total of 1100 were subsequently diagnosed with recurrence, including 311 (28.3%) with AR and 789 (71.7%) with SR. Median time from RC to recurrence was longer in the AR group (13.2 months) than in the SR group (10.8 months; p = 0.01). Presenting symptoms included pain (70.2%), constitutional symptoms (50.7%), gastrointestinal symptoms (23.3%), and urinary symptoms (23.3%). Median follow-up after recurrence was 2.4 years (IQR 1.1-5.5), during which time 997 patients died, including 840 who died of bladder cancer. Compared to patients with SR, patients with AR had a longer median CSS (54.5 months vs 27.3 months, p < 0.001) and OS (43.0 months vs 25.8 months, p < 0.001). On multivariable Cox proportional hazards models adjusting for demographic and clinical factors, SR was associated with a significantly increased risk of cancer-specific (hazard ratio [HR] 1.66 [95% confidence interval 1.41-1.96], p < 0.0001) and all-cause mortality (HR 1.48 [1.23-1.71], p < 0.0001). Conclusions: SR after RC is associated with worse oncologic outcomes than post-RC recurrence detected by routine surveillance. As such, continued surveillance is warranted, while further study is needed to determine the optimal follow-up regimen balancing patient and disease risks.

395 Background: Patients with BCG-unresponsive carcinoma in situ (CIS) are treated with radical cystectomy (RCx) or salvage intravesical chemotherapy (SIC). Recently, the FDA approved pembrolizumab for BCG-unresponsive CIS +/- papillary tumors. Given the costs and toxicities of pembrolizumab, it remains unclear whether its benefits are sufficient to warrant widespread use for BCG-unresponsive CIS. To that end, we conducted a cost-effectiveness analysis comparing pembrolizumab with RCx and SIC (using gemcitabine-docetaxel as the prototypical regimen) for patients with BCG-unresponsive CIS. Methods: A decision-analytic Markov model compared pembrolizumab, SIC (with gemcitabine-docetaxel), and RCx for patients with BCG-unresponsive CIS +/- papillary tumors who are RCx candidates (index patient 1) or are unwilling/unable to undergo RCx (index patient 2). Each treatment option was a Markov node containing distinct variations of the following health states: surveillance, recurrence, progression to MIBC, progression to metastasis, treatment toxicity, and death. Incremental Cost-Effectiveness Ratios (ICERs) were compared using a willingness-to-pay threshold of $100,000/Quality-adjusted life year (QALY). The model used a US Medicare perspective with a 5-year time horizon for the base case. One-way and probabilistic sensitivity analyses were performed for all model parameters. Results: For index patient 1, pembrolizumab was not cost-effective vs. RCx (ICER $1,403,008) or SIC (ICER $2,011,923). One-way sensitivity analysis revealed that pembrolizumab only became cost-effective relative to RCx with a > 93% price reduction. Relative to RCx, SIC was cost-effective for time horizons < 5 years and nearly cost-effective at 5 years (ICER $118,324). One-way sensitivity analysis revealed that SIC became cost-effective relative to RCx if its risk of recurrence or metastasis at 2 years was less than 55% or 5.9%, respectively. For index patient 2, pembrolizumab required > 90% price reduction to be cost-effective vs. RCx (ICER $1,073,240). Probabilistic sensitivity analyses revealed that pembrolizumab was unlikely to be cost-effective even at high willingness-to-pay thresholds. Further sensitivity analyses found that no two-way combination of extrapolated values resulted in pembrolizumab being favored over RCx or SIC for either index patient. Conclusions: Based on decision-analytic Markov modeling of treatment options for patients with BCG-unresponsive CIS, pembrolizumab was unlikely to be cost-effective without a > 90% price reduction. While both RCx and SIC were more cost-effective than pembrolizumab, further studies may validate the cost-effectiveness of gemcitabine-docetaxel relative to RCx if the recurrence and metastasis thresholds are met. Overall, our model supports the preferential use of RCx and SIC over pembrolizumab for BCG-unresponsive CIS.