A phase II single-arm trial of memantine for prevention of cognitive decline during chemotherapy in patients with early breast cancer: Feasibility, tolerability, acceptability, and preliminary effects.

BACKGROUND: Cognitive difficulties have been described after chemotherapy for breast cancer, but there is no standard of care to improve cognitive outcomes in these patients. This trial examined the feasibility, tolerability, acceptability, and preliminary effects of memantine to prevent cognitive decline during chemotherapy for breast cancer. METHODS: Patients with stage I-III breast cancer, scheduled for neo/adjuvant chemotherapy, completed a cognitive battery prior to and 4 weeks after completing chemotherapy. Memantine (10 mg BID) was administered concurrent with chemotherapy. Our primary cognitive outcome was visual working memory assessed by the Delayed Matching to Sample test. We used the Brief Medication Questionnaire to assess acceptability. RESULTS: Of 126 patients approached, 56 (44%) enrolled. Forty-five (80%) received ≥1 dose of memantine and completed pre-post assessments. Seventy-six percent reported taking ≥90% of scheduled doses. Participants were mean age of 56, 77% White, and 57% had stage I disease. Sixty-four percent had stable or improved Delayed Matching to Sample test scores. Stable or improved cognition was observed in 87%-91% across objective cognitive domain composite measures. Sixty-six percent self-reported stable or improved cognitive symptoms. There were seven greater than or equal to grade 3 adverse events; two were possibly related to memantine. Only 5% reported that taking memantine was a disruption to their lives. CONCLUSIONS: Memantine was well-tolerated and consistently taken by a large majority of patients receiving breast cancer chemotherapy. The majority demonstrated stable or improved cognition from pre- to post-assessment. Randomized trials are needed to determine memantine's efficacy to ameliorate cognitive loss. TRIAL REGISTRATION: ClinicalTrials.gov NCT04033419.

A randomized controlled trial comparing changes in fitness with or without supervised exercise in patients initiated on enzalutamide and androgen deprivation therapy for non-metastatic castration-sensitive prostate cancer (EXTEND).

BACKGROUND: Androgen deprivation therapy (ADT) and androgen receptor signaling inhibitors (ARSI) are associated with deleterious physical effects, which exercise may mitigate; however, exercise has never been studied in patients initiating treatment with ADT and an ARSI. Our objective was to determine whether supervised exercise prior to and during initial therapy could mitigate adverse effects of ADT plus enzalutamide. METHODS: We conducted a single center trial in patients with recurrent prostate cancer treated with ADT and enzalutamide. We randomized 26 patients to 16 weeks of supervised exercise (aerobic and resistance), starting 4 weeks before initiation of ADT and enzalutamide, or usual care. The primary endpoint was change in peak oxygen uptake (VO2peak) as a measure of cardiorespiratory fitness (CRF). Secondary endpoints were functional capacity, maximal strength, body composition, patient-reported outcomes, safety, and feasibility. Analysis of covariance was used to compare outcomes for groups at Week 17 adjusted for baseline values. RESULTS: The usual care group (N = 13) showed declines from baseline to week 17 in both absolute CRF (-0.31 L/min, -10.9%; p < 0.01) and relative CRF (-3.2 mL/kg/min, -8.9%; p = 0.04); worse fatigue (p = 0.01); and worse quality of life (p = 0.01). At week 17, the exercise group (N = 13) demonstrated improved absolute CRF (between-group change +0.20 L/min, p = 0.05), leg strength (+48.6 kg, p < 0.01) and functional capacity (+21.0 m, p = 0.01) at week 17. CONCLUSIONS: This is the first randomized controlled trial demonstrating a clinically significant decline in CRF in patients initiating ADT and enzalutamide. We show the effectiveness of short-term supervised exercise to mitigate declines in absolute CRF, and improve maximal leg strength and functional capacity. GOV IDENTIFIER: NCT02256111.

Expression of immune checkpoints on circulating tumor cells in men with metastatic prostate cancer.

BACKGROUND: A subset of men with metastatic prostate cancer (mPC) responds to immune checkpoint inhibitors, and there is an unmet need to predict those most likely to benefit. We characterized circulating tumor cells (CTCs) for expression of immune checkpoint ligands in men with mPC as a non-invasive biomarker of immune evasion and immunotherapy benefit. METHODS: Three cohorts of patients were enrolled: 1) men with mCRPC starting abiraterone acetate/prednisone or enzalutamide (pre-ARSI), 2) men with mCRPC who were progressing on enzalutamide or abiraterone acetate/prednisone (post-ARSI), and 3) men with newly diagnosed metastatic hormone sensitive prostate cancer (mHSPC) starting androgen deprivation therapy. CTCs were captured using the CellSearch® system and stained for PD-L1, PD-L2, B7-H3, and CTLA-4 at baseline, on treatment, and disease progression. Summary statistics on mean CTCs per cohort, as well as rates of ligand positivity were used to analyze CTCs by cohort and by timepoint. RESULTS: Men in all cohorts and timepoints had prevalent CTC B7-H3 expression (> 80%). We found evidence for CTC PD-L1 expression across disease states, in which > 1 positive CTC or > 50% of CTCs were positive for PD-L1 in 40 and 30% of men with mHSPC, respectively, 60 and 20% of men with mCRPC pre-ARSI, and 70 and 30% of men with mCRPC post-ARSI. CTC PD-L2 expression was present in 20-40% of men in each disease state, while CTC CTLA-4 expression was rare, present in 20% of men with mCRPC pre-ARSI and 10% of men with mCRPC post-ARSI or with mHSPC. CTC immune checkpoint expression was heterogeneous within/between men and across disease states. CONCLUSIONS: We have identified that CTCs from men with mPC heterogeneously express immune checkpoints B7-H3, PD-L1, PD-L2, and CTLA-4, and the detection of these immune checkpoints may enable monitoring on immunotherapy.

Prolonged PSA stabilization and overall survival following sipuleucel-T monotherapy in metastatic castration-resistant prostate cancer patients.

BACKGROUND: Sipuleucel-T is an autologous cellular immunotherapy that is FDA approved for the treatment of asymptomatic or minimally symptomatic metastatic castrate-resistant prostate cancer (mCRPC). The IMPACT registry trial demonstrated a 4.1 month survival benefit, but not a consistent PSA response or improvement in progression-free survival. Based upon several factors, including this lack of objective treatment response, sipuleucel-T has been under-utilized in this patient population, despite current NCCN recommendations. METHODS: In order to explore if delayed treatment response occurs in a subset of patients, we performed a single institutional retrospective analysis of mCRPC patients treated with sipuleucel-T and ongoing ADT alone. Within that group, we then identified a subset of sipuleucel-T-treated men with long-term disease control and no additional interventions. To independently confirm this finding, we evaluated a total of 336 patients from 4 large urology group practices treated with sipuleucel-T between 2010 and 2014 and identified 44 patients who met the same criteria and demonstrated evidence of PSA stabilization post sipuleucel-T treatment. RESULTS: For this subgroup of patients, 79% (95% CI: 64.5%, 88.1%) survived 36 months with a median time to subsequent therapy of 17.8 months (95% CI 10.3, 25.3). CONCLUSIONS: Although patient selection could account for some or all of these results, these data support the utilization of sipuleucel-T alone in select mCRPC patients that is associated with a delay in disease progression and a good overall prognosis.

Immunotherapy Is Changing First-Line Treatment of Metastatic Renal-Cell Carcinoma.

The incidence of renal-cell carcinoma has been increasing each year, with nearly one third of new cases diagnosed at advanced or metastatic stage. The advent of targeted therapies for metastatic renal-cell carcinoma (mRCC) has underscored the need to subtype tumors according to tumor-immune expression profiles that may more reliably predict treatment outcomes. Over the past 2 decades, several vascular endothelial growth factor (VEGF) and tyrosine kinase inhibitors have been the mainstay for first- and second-line treatment of mRCC. Very recently, immunotherapy checkpoint inhibitors have significantly changed the treatment landscape for patients with mRCC, particularly for first-line treatment of intermediate to poor risk mRCC patients. Now, combination immunotherapy as well as combinations of immunotherapy with targeted agents can significantly alter disease outcomes. The field of immuno-oncology for mRCC has unveiled a deeper understanding of the immunoreactivity inherent to these tumors, and as a result combination therapy is evolving as a first-line modality. This review provides a timeline of advances and controversies in first-line treatment of mRCC, describes recent advances in understanding the immunoreactivity of these tumors, and addresses the future of combination anti-VEGF and immunotherapeutic platforms.

Recombinant oncolytic poliovirus, PVSRIPO, has potent cytotoxic and innate inflammatory effects, mediating therapy in human breast and prostate cancer xenograft models.

Intratumoral inoculation of viruses with tumor-selective cytotoxicity may induce cancer cell death and, thereby, shrink neoplastic lesions. It is unlikely, however, that viral tumor cell killing alone could produce meaningful, durable clinical responses, as clinically suitable 'oncolytic' viruses are severely attenuated and their spread and propagation are opposed by host immunity. Thus, a more propitious event in this context is the innate antiviral response to intratumoral virus administration, in particular for recruiting durable adaptive immune effector responses. It may represent a double-edged sword, as innate immune activation may eliminate infected tumor cells early, intercept viral spread and block any meaningful therapeutic response. The innate response to viral infection of tumors may be very different from that in non-malignant target tissues, owing to the unusual composition/tissue properties of tumor stroma. In this work, we report investigations of the innate immune response to the oncolytic poliovirus recombinant, PVSRIPO, in two mouse xenotransplantation models for breast and prostate cancer. Our observations indicate short-term virus persistence in infected tumors and virus recovery indicative of modest intratumoral propagation and persistence. Yet, a powerful innate inflammatory response coincided with chemokine induction and myeloid cell infiltration into tumors that was, interestingly, dominated by neutrophils. The combined effect of PVSRIPO tumor infection and the innate response it elicits was significant tumor regression in both models.

RNA-Based Vaccines in Cancer Immunotherapy.

RNA vaccines traditionally consist of messenger RNA synthesized by in vitro transcription using a bacteriophage RNA polymerase and template DNA that encodes the antigen(s) of interest. Once administered and internalized by host cells, the mRNA transcripts are translated directly in the cytoplasm and then the resulting antigens are presented to antigen presenting cells to stimulate an immune response. Alternatively, dendritic cells can be loaded with either tumor associated antigen mRNA or total tumor RNA and delivered to the host to elicit a specific immune response. In this review, we will explain why RNA vaccines represent an attractive platform for cancer immunotherapy, discuss modifications to RNA structure that have been developed to optimize mRNA vaccine stability and translational efficiency, and describe strategies for nonviral delivery of mRNA vaccines, highlighting key preclinical and clinical data related to cancer immunotherapy.

Pain, PSA flare, and bone scan response in a patient with metastatic castration-resistant prostate cancer treated with radium-223, a case report.

BACKGROUND: Radium-223 has been shown to improve overall survival in men with metastatic castration-resistant prostate cancer with symptomatic bone metastases. The bone scan response to radium-223 has only been described in one single center trial of 14 patients, none of whom achieved the outstanding bone scan response presented in the current case. CASE PRESENTATION: In this case report, we describe a 75 year-old white man with extensively pre-treated metastatic castration-resistant prostate cancer and symptomatic bone metastases who experienced a flare in pain and prostate-specific antigen, followed by dramatic clinical (pain), biochemical (prostate-specific antigen), and imaging (bone scan) response. CONCLUSION: The flare phenomena and bone scan response we observed have not previously been described with radium-223. This case suggests that the degree and duration of bone scan response may be predictive of overall survival benefit.