Dendritic cell vaccination in combination with docetaxel for patients with metastatic castration-resistant prostate cancer: A randomized phase II study.

BACKGROUND AIMS: We investigated whether the addition of an autologous dendritic cell-based cancer vaccine (DCvac) induces an immune response in patients with metastatic castration-resistant prostate cancer treated with docetaxel. METHODS: Forty-three patients were randomized 1:1 to receive up to 10 cycles of docetaxel alone, 75 mg/m2 every 3 weeks or in combination with DCvac. Monocytes were harvested following a leukapheresis procedure, matured ex vivo and subsequently transfected with messenger RNA encoding multiple tumor-associated antigens (TAAs). DCvac was administered intradermally twice through treatment cycles 1-4 and once through treatment cycles 5-10. Immune cell composition and antigen-specific responses were analyzed using flow cytometry, ELISpot and delayed type hypersensitivity (DTH) tests. Toxicity was graded according to Common Terminology Criteria for Adverse Events version 3.0. Progression-free survival (PFS) and disease-specific survival (DSS) was calculated using the Kaplan-Meier method. RESULTS: Prostate-specific antigen responses were similar in patients treated with docetaxel alone and combination therapy (58% versus 38%; P = 0.21). PFS and DSS were comparable: 5.5 versus 5.7 months (P = 0.62, log rank) and 21.9 versus 25.1 months (P = 0.60, log rank). Nine (50%) and 14 (78%) patients treated with docetaxel and DCvac had a TAA-specific or vaccine-specific immune response in the ELISpot and DTH analysis, respectively. Vaccine induced toxicity was limited to local reactions. Decline in myeloid-derived suppressor cells at the third treatment cycle was found to be an independent predictor of DSS. CONCLUSIONS: The addition of DCvac was safe. Immune responses were detected in approximately half of the patients investigated.

Cabazitaxel as second-line or third-line therapy in patients with metastatic castration-resistant prostate cancer.

To compare treatment outcomes in patients with metastatic castration-resistant prostate cancer treated with cabazitaxel (CA) as second-line or third-line therapy in the everyday clinical setting. Charts from 94 patients treated with CA as second-line (n=28) or third-line therapy (n=66) were evaluated. Common Terminology Criteria for Adverse Events were used to register grade 3-4 nonhematological toxicity during treatment with CA. Baseline metastatic castration-resistant prostate cancer-related prognostic factors, duration of therapy, and maximum prostate-specific antigen (PSA) percentage change were registered during treatment with CA and previous/subsequent novel androgen receptor targeting therapies. Progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. A median of 6 versus 5 treatment cycles was administered in patients treated with second-line and third-line CA (P=0.483). Events with grade 3-4 nonhematological toxicity were equally distributed in the two groups (32 vs. 35%, P=0.80). PSA responses were observed in 46 and 17% of patients treated with second-line and third-line CA (P=0.002). PFS (5.5 vs. 3.3 months, P=0.087, log rank) and OS (18.3 vs. 11.4 months, P=0.003, log rank) was longer in patients treated with second-line CA. OS measured from second-line abiraterone acetate/enzalutamide was similar (18.0 months) to second-line CA (P=0.883, log rank). Treatment-related toxicity was independent of CA being administered as second-line or third-line therapy. Although PFS and the frequency of PSA responders favored patients treated with second-line CA, one treatment sequence could not be considered superior to the other in this study.

Correlation between frequencies of blood monocytic myeloid-derived suppressor cells, regulatory T cells and negative prognostic markers in patients with castration-resistant metastatic prostate cancer.

Myeloid-derived suppressor cells (MDSC) are believed to play a role in immune suppression and subsequent failure of T cells to mount an efficient anti-tumor response, by employing both direct T-cell inhibition as well as induction of regulatory T cells (Tregs). Investigating the frequency and function of immune suppressive cell subsets in the peripheral blood of 41 patients with prostate cancer (PC) and 36 healthy donors (HD) showed a significant increase in circulating CD14(+) HLA-DR(low/neg) monocytic MDSC (M-MDSC) and Tregs in patients with PC compared to HD. Furthermore, M-MDSC frequencies correlated positively with Treg levels. In vitro proliferation assay with autologous T cells confirmed M-MDSC-mediated T-cell suppression, and intracellular staining of immune suppressive enzyme iNOS revealed a higher expression in M-MDSC from patients with PC. Increased frequencies of M-MDSC correlated with known negative prognostic markers in patients with PC including elevated levels of lactate dehydrogenase and prostate-specific antigen. Accordingly, high levels of M-MDSC were associated with a shorter median overall survival. Our data strongly suggest that M-MDSC, possibly along with Tregs, play a role in establishing an immune suppressive environment in patients with PC. Moreover, correlation of M-MDSC frequency with known prognostic markers and the observed impact on OS could reflect a possible role in tumor progression. Further insight into the generation and function of MDSC and their interplay with Tregs and other cell types may suggest ways to tackle their induction and/or function to improve immunological tumor control.

First in man study: Bcl-Xl_42-CAF®09b vaccines in patients with locally advanced prostate cancer.

Background: The B-cell lymphoma-extra-large (Bcl-XL) protein plays an important role in cancer cells' resistance to apoptosis. Pre-clinical studies have shown that vaccination with Bcl-XL-derived peptides can induce tumor-specific T cell responses that may lead to the elimination of cancer cells. Furthermore, pre-clinical studies of the novel adjuvant CAF®09b have shown that intraperitoneal (IP) injections of this adjuvant can improve the activation of the immune system. In this study, patients with hormone-sensitive prostate cancer (PC) received a vaccine consisting of Bcl-XL-peptide with CAF®09b as an adjuvant. The primary aim was to evaluate the tolerability and safety of IP and intramuscular (IM) administration, determine the optimal route of administration, and characterize vaccine immunogenicity. Patients and methods: Twenty patients were included. A total of six vaccinations were scheduled: in Group A (IM to IP injections), ten patients received three vaccines IM biweekly; after a three-week pause, patients then received three vaccines IP biweekly. In Group B (IP to IM injections), ten patients received IP vaccines first, followed by IM under a similar vaccination schedule. Safety was assessed by logging and evaluating adverse events (AE) according to Common Terminology Criteria for Adverse Events (CTCAE v. 4.0). Vaccines-induced immune responses were analyzed by Enzyme-Linked Immunospot and flow cytometry. Results: No serious AEs were reported. Although an increase in T cell response against the Bcl-XL-peptide was found in all patients, a larger proportion of patients in group B demonstrated earlier and stronger immune responses to the vaccine compared to patients in group A. Further, we demonstrated vaccine-induced immunity towards patient-specific CD4, and CD8 T cell epitopes embedded in Bcl-XL-peptide and an increase in CD4 and CD8 T cell activation markers CD107a and CD137 following vaccination. At a median follow-up of 21 months, no patients had experienced clinically significant disease progression. Conclusion: The Bcl-XL-peptide-CAF®09b vaccination was feasible and safe in patients with l hormone-sensitive PC. In addition, the vaccine was immunogenic and able to elicit CD4 and CD8 T cell responses with initial IP administration eliciting early and high levels of vaccine-specific responses in a higher number og patients. Clinical trial registration: https://clinicaltrials.gov, identifier NCT03412786.

Clinical efficacy of T-cell therapy after short-term BRAF-inhibitor priming in patients with checkpoint inhibitor-resistant metastatic melanoma.

PURPOSE: Despite impressive response rates following adoptive transfer of autologous tumor-infiltrating lymphocytes (TILs) in patients with metastatic melanoma, improvement is needed to increase the efficacy and broaden the applicability of this treatment. We evaluated the use of vemurafenib, a small-molecule BRAF inhibitor with immunomodulatory properties, as priming before TIL harvest and adoptive T cell therapy in a phase I/II clinical trial. METHODS: 12 patients were treated with vemurafenib for 7 days before tumor excision and during the following weeks until TIL infusion. TILs were grown from tumor fragments, expanded in vitro and reinfused to the patient preceded by a lymphodepleting chemotherapy regimen and followed by interleukin-2 infusion. Extensive immune monitoring, tumor profiling and T cell receptor sequencing were performed. RESULTS: No unexpected toxicity was observed, and treatment was well tolerated. Of 12 patients, 1 achieved a complete response, 8 achieved partial response and 3 achieved stable disease. A PR and the CR are ongoing for 23 and 43 months, respectively. In vitro anti-tumor reactivity was found in TILs from 10 patients, including all patients achieving objective response. Serum and tumor biomarker analyses indicate that baseline cytokine levels and the number of T cell clones may predict response to TIL therapy. Further, TCR sequencing suggested skewing of TCR repertoire during in vitro expansion, promoting certain low frequency clonotypes. CONCLUSIONS: Priming with vemurafenib before infusion of TILs was safe and feasible, and induced objective clinical responses in this cohort of patients with checkpoint inhibitor-resistant metastatic melanoma. In this trial, vemurafenib treatment seemed to decrease attrition and could be considered to bridge the waiting time while TILs are prepared.

Clinical Impact of the Number of Treatment Cycles in First-Line Docetaxel for Patients With Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: We investigated the impact of the number of docetaxel cycles administered in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with first-line chemotherapy. PATIENTS AND METHODS: Charts from 421 consecutive patients who initiated standard treatment with docetaxel-based chemotherapy (75 mg/m2 every 3 weeks) between 2007 and 2013 were reviewed. Patients who received < 6 cycles of docetaxel were excluded from the analysis. Remaining patients were divided into 2 groups on the basis of whether or not ≥ 9 cycles of docetaxel were administered (n = 108 and 184, respectively). Reasons for treatment discontinuation and postdocetaxel treatments were registered. Prostate-specific antigen (PSA) responses were defined as a confirmed ≥ 50% decrease in baseline PSA levels. Overall survival (OS) was calculated from start of therapy using the Kaplan-Meier method. Cox proportional hazards were calculated to estimate the effect of clinical variables on OS. RESULTS: OS was longer in patients treated with ≥ 9 cycles of docetaxel (21.9 months vs. 17.2 months; P < .0001, log rank). Survival also favored patients treated with ≥ 9 cycles of docetaxel when only patients ending docetaxel because of toxicity or treatment conclusion (22.3 vs. 19.4 months; P = .048, log rank) or patients who achieved a PSA response (22.3 vs. 18.7 months; P = .012, log rank) were evaluated. mCRPC-related prognostic factors and patients who received ≥ 1 subsequent line of therapy post-docetaxel were well balanced. CONCLUSION: On the basis of our retrospective findings, a superior OS was found in patients treated with ≥ 9 cycles of docetaxel when adjusting for known prognostic factors. Dose reductions might increase the number of docetaxel cycles administered.

Predictors of Chemotherapy-Induced Toxicity and Treatment Outcomes in Elderly Versus Younger Patients With Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: In the present study, we examined possible predictors of chemotherapy-induced toxicity, treatment outcomes, and the consequences of dose reductions in patients with metastatic castration-resistant prostate cancer (mCRPC) receiving standard docetaxel. PATIENTS AND METHODS: Medical records from 421 consecutive patients treated with first-line docetaxel (75 mg/m2 every 3 weeks) and low-dose prednisolone from 2007 to 2013 at Herlev University Hospital were reviewed. Common Terminology Criteria for Adverse Events, version 4.0, and the Prostate Cancer Working Group 2 guidelines were used to evaluate treatment-related toxicity and efficacy. Logistic and Cox regression models were used to predict toxicity and survival. RESULTS: Age ≥ 75 years (odds ratio [OR], 2.33), baseline levels of hemoglobin (OR, 0.89), and previous metastatic epidural spinal cord compression (MESCC; OR, 1.70) were predictive of grade 3 and 4 nonhematologic toxicity. Previous MESCC was associated with a greater risk of febrile neutropenia (OR, 2.74). The median progression-free survival (PFS) and overall survival (OS) were 6.4 and 15.4 months, respectively. Survival was similar in the older (age ≥ 75 years) and younger patients (PPFS = .66, POS = .90; log-rank) and when comparing patients undergoing dose reductions with patients treated with standard docetaxel throughout their treatment course (PPFS = .51 and POS = 0.52; log-rank). A longer interval from the primary diagnosis to the initiation of docetaxel (hazard ratio [HR], 1.00), baseline hemoglobin levels (HR, 0.85), Eastern Cooperative Oncology Group performance status > 0 to 1 (HR, 1.44), lactate dehydrogenase greater than the upper limit of normal (HR, 1.64), and prostate-specific antigen levels (HR, 1.00) were predictors of OS. CONCLUSIONS: OS in the everyday clinical setting was inferior to that observed in randomized trials. Our results indicate that elderly patients and patients with moderate anemia or a history of MESCC at baseline have a greater risk of treatment-induced toxicity. Dose reductions did not compromise survival.

Long-Lasting Complete Responses in Patients with Metastatic Melanoma after Adoptive Cell Therapy with Tumor-Infiltrating Lymphocytes and an Attenuated IL2 Regimen.

PURPOSE: Adoptive cell transfer therapy (ACT) based on autologous tumor-infiltrating lymphocytes (TIL) has achieved impressive clinical results in several phase I and II trials performed outside of Europe. Although transient, the toxicities associated with high-dose (HD) bolus IL2 classically administered together with TILs are severe. To further scrutinize whether similar results can be achieved with lower doses of IL2, we have carried out a phase I/II trial of TIL transfer after classical lymphodepleting chemotherapy followed by an attenuated IL2 regimen. EXPERIMENTAL DESIGN: Twenty-five patients with progressive treatment-refractory metastatic melanoma, good clinical performance, age < 70 years, and at least one resectable metastasis were eligible. TIL infusion was preceded by standard lymphodepleting chemotherapy and followed by attenuated doses of IL2 administered in an intravenous, continuous decrescendo regimen (ClinicalTrials.gov Identifier: NCT00937625). RESULTS: Classical IL2-related toxicities were observed but patients were manageable in a general oncology ward without the need for intervention from the intensive care unit. RECIST 1.0 evaluation displayed three complete responses and seven partial responses (ORR 42%). Median overall survival was 21.8 months. Tumor regression was associated with a higher absolute number of infused tumor-reactive T cells. Moreover, induction and persistence of antimelanoma T-cell responses in the peripheral blood was strongly correlated to clinical response to treatment. CONCLUSIONS: TIL-ACT with a reduced IL2 decrescendo regimen results in long-lasting complete responses in patients with treatment-refractory melanoma. Larger randomized trials are needed to elucidate whether clinical efficacy is comparable with TIL-ACT followed by HD bolus IL2. Clin Cancer Res; 22(15); 3734-45. ©2016 AACR.

Low-dose prednisolone in first-line docetaxel for patients with metastatic castration-resistant prostate cancer: is there a clinical benefit?

BACKGROUND: Randomized studies have shown improved survival with the combination of docetaxel (D) and prednisone in patients with metastatic castration-resistant prostate cancer (mCRPC). We retrospectively investigated whether coadministration of low-dose glucocorticoids has clinical benefits. MATERIAL AND METHODS: Records from 358 patients with metastatic castration-resistant prostate cancer treated consecutively with either D 75mg/m(2) every 3 weeks (n = 124) (Rigshospitalet) or D and prednisolone (P) 10mg daily (n = 234) (Herlev Hospital) given as first-line chemotherapy were reviewed. Of these, 15 patients treated with glucocorticoids at initiation of D at Rigshospitalet were excluded. Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 was used to register any grade of peripheral edema, grade ≥2 sensory neuropathy, and grade ≥3 nonhematological toxicity. Background clinical data, rates of toxicity, hospital admissions, dose reductions, and post-D treatments were analyzed by the Chi-squared test or Mann-Whitney U test. Progression-free survival and overall survival were calculated by the Kaplan-Meier method. RESULTS: Patients treated with D alone had a higher incidence of peripheral edema (32% vs. 15%, P<0.001) and grade 3 nonhematological toxicity (56% vs. 43%, P = 0.022). Patients treated with D alone were also more frequently hospitalized (53% vs. 41%, P = 0.035), mainly owing to a higher incidence of febrile neutropenia in this group (25% vs. 10%, P<0.001). P did not influence progression-free survival (P = 0.692, log-rank test) or overall survival when adjusting for baseline levels of hemoglobin, alkaline phosphatase, lactate dehydrogenase, prostate-specific antigen, and Eastern Cooperative Oncology Group performance status (hazard ratioP = 0.98, 95% CI: 0.76-1.26, P = 0.89, Cox proportional hazard regression model). CONCLUSIONS: Coadministration of low-dose P reduced the incidence of peripheral edema, grade 3 nonhematological toxicity, and the risk of being admitted owing to febrile neutropenia during treatment with D. Adjusted survival analysis did not indicate that P affected prognosis.

[Fatal neutropenic enterocolitis in a patient with castration-resistant prostate cancer treated with first-line chemotherapy]. / Fatal neutropen enterokolitis hos en patient i kemoterapi med kastrationsresistent prostatacancer.

Neutropenic enterocolitis (NE) is a possible life-threatening complication to chemotherapy. The pathogenesis is multi-factorial with mucosal injury and impaired mucosal defence as contributing factors. Histopathological findings are heterogeneous. Clinical presentation includes neutropenia, fever and abdominal pain. Treatment is not clearly defined. We present a fatal case of NE in a patient with prostate cancer treated with first-line chemotherapy, docetaxel 75 mg/m2 every three weeks and prednisolone 5 mg × 2 daily. The post-mortem examination confirmed NE with prostate cancer cells in bowel wall.

Tryptophan 2,3-dioxygenase (TDO)-reactive T cells differ in their functional characteristics in health and cancer.

Tryptophan-2,3-dioxygenase (TDO) physiologically regulates systemic tryptophan levels in the liver. However, numerous studies have linked cancer with activation of local and systemic tryptophan metabolism. Indeed, similar to other heme dioxygenases TDO is constitutively expressed in many cancers. In the present study, we detected the presence of both CD8+ and CD4+ T-cell reactivity toward TDO in peripheral blood of patients with malignant melanoma (MM) or breast cancer (BC) as well as healthy subjects. However, TDO-reactive CD4+ T cells constituted distinct functional phenotypes in health and disease. In healthy subjects these cells predominately comprised interferon (IFN)γ and tumor necrosis factor (TNF)-α producing Th1 cells, while in cancer patients TDO-reactive CD4+ T-cells were more differentiated with release of not only IFNγ and TNFα, but also interleukin (IL)-17 and IL-10 in response to TDO-derived MHC-class II restricted peptides. Hence, in healthy donors (HD) a Th1 helper response was predominant, whereas in cancer patients CD4+ T-cell responses were skewed toward a regulatory T cell (Treg) response. Furthermore, MM patients hosting a TDO-specific IL-17 response showed a trend toward an improved overall survival (OS) compared to MM patients with IL-10 producing, TDO-reactive CD4+ T cells. For further characterization, we isolated and expanded both CD8+ and CD4+ TDO-reactive T cells in vitro. TDO-reactive CD8+ T cells were able to kill HLA-matched tumor cells of different origin. Interestingly, the processed and presented TDO-derived epitopes varied between different cancer cells. With respect to CD4+ TDO-reactive T cells, in vitro expanded T-cell cultures comprised a Th1 and/or a Treg phenotype. In summary, our data demonstrate that the immune modulating enzyme TDO is a target for CD8+ and CD4+ T cell responses both in healthy subjects as well as patients with cancer; notably, however, the functional phenotype of these T-cell responses differ depending on the respective conditions of the host.