Docetaxel and epirubicin compared with docetaxel and prednisone in advanced castrate-resistant prostate cancer: a randomised phase II study

Incidence of fatigue and low-dose corticosteroid use in prostate cancer patients receiving systemic treatment: a meta-analysis of randomized controlled trials

BACKGROUND

Cancer-related fatigue (CRF) is a complex condition that is reported in > 50% of cancer patients. In men with castration-resistant prostate cancer (CRPC), CRF was reported in 12-21% of patients. Approved systemic therapy against CRPC is commonly administered in combination with androgen-deprivation treatment (ADT) and, in some cases, with daily, low-dose corticosteroids. Importantly, the use of low-dose corticosteroids is associated with multiple negative effects, including reduced muscle mass. On these grounds, we hypothesized that the chronic use of corticosteroids may increase the incidence of fatigue in patients with prostate cancer.

METHODS

We reviewed all randomized trials published during the last 15 years conducted in patients with prostate cancer receiving systemic treatment and we performed a sub-group analysis to gather insights regarding the potential differences in the incidence of fatigue in patients receiving vs. not receiving daily corticosteroids as part of their systemic anti-neoplastic regimen.

RESULTS

Overall, 22,734 men enrolled in prospective randomized phase II and III trials were evaluable for fatigue. Estimated pooled incidence of grade 1-2 fatigue was 30.89% (95% CI = 25.34-36.74), while estimated pooled incidence of grade 3-4 fatigue was reported in 3.90% (95% CI = 2.91-5.02). Sub-group analysis showed that grade 3-4 fatigue was approximately double in patients who received daily corticosteroids as part of their anti-neoplastic treatment (5.58; 95% CI = 4.33-6.98) vs. those who did not (2.67%; 95% CI = 1.53-4.11).

CONCLUSION

Our findings highlight the need for ad hoc-designed prospective clinical trials to investigate whether the benefits associated with low-dose, daily corticosteroids outweigh the risks associated with corticosteroid-related adverse events such as fatigue.

RNA interference-mediated depletion of TRPM8 enhances the efficacy of epirubicin chemotherapy in prostate cancer LNCaP and PC3 cells

Several studies have shown that transient receptor potential cation channel subfamily M member 8 (TRPM8), which has been regarded as a novel prostate-specific marker, serves a key role in processes such as the proliferation, viability and cell migration of prostate cancer cells. Efforts have been made to uncover the potential role of targeting TRPM8 in the management of prostate cancer; it has been verified that TRPM8-targeted blockade, either by RNA interference-mediated depletion or specific TRPM8 inhibitors, could reduce the rate of proliferation and proliferative fraction, and induce apoptosis in prostate cancer cells. The aim of the present study was to investigate the effect of knockdown of TRPM8 on chemosensitivity in prostate cancer LNCaP and PC3 cells. The RNA interference-mediated depletion of TRPM8 inhibited proliferation and enhanced epirubicin chemosensitivity of LNCaP and PC3 cells, and promoted epirubicin-induced apoptosis by increasing the phosphorylation of p38 mitogen-activated protein kinase (hereafter p38) and c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase signaling pathways, which was demonstrated via the use of specific inhibitors of phosphorylation of p38 and JNK. The results demonstrate that the targeted silencing of TRPM8 expression is a therapeutic strategy for treatment of prostate cancer that has considerable potential, even for castration-resistant prostate cancer.

Chemotherapy options in castration-resistant prostate cancer

Introduction:

The treatment landscape for patients with metastatic castration-resistant prostate cancer (CRPC) is evolving, with recent approvals of immune therapy, novel hormonal therapy, and bone-targeted therapy. Chemotherapy remains an essential component of the armamentarium. Herein, we review current chemotherapy options for patients with CRPC and discuss future challenges.

Methods:

We reviewed literature for chemotherapy agents in prostate cancer, with special attention to the evidence for efficacy of the currently approved agents. We also reviewed emerging data on biomarkers of response to chemotherapy for CRPC.

Results:

Taxanes, especially docetaxel and cabazitaxel, have first- and second-line indications for CRPC, respectively, with both providing a survival benefit. Multiple attempts to improve on the single agent efficacy of docetaxel with combination therapy have not generally been successful although platinum combinations are used for resistant phenotypes. Reductions in prostate-specific antigen by ≥30% and reductions in circulating tumor cells (CTCs) to ≤ 5 are associated with improved survival on chemotherapy. Chemotherapy may continue to be effective therapy for patients with biomarkers that are associated with resistance to androgen-directed therapies (androgen receptor splice variant 7 positivity in CTCs or high CTC heterogeneity).

Conclusions:

Chemotherapy remains an essential component of CRPC therapy, and biomarkers are being identified to define clinical scenarios where chemotherapy may be the optimal therapy choice.

Is there still a place for docetaxel rechallenge in prostate cancer?

Three-weekly docetaxel plus prednisone is the standard first-line cytotoxic treatment for patients with metastatic castrate-resistant prostate cancer (mCRPC). Today, several new treatment options are available for patients with tumor progression after first-line docetaxel: Abiraterone, enzalutamide, cabazitaxel, sipuleucel-T immunotherapy, and the radionuclide radium-223. However, despite the evolving scenario in CRPC treatment, the optimal sequencing of the innovative therapies remains unclear. The reintroduction of docetaxel at the occurrence of disease progression after a drug holiday (docetaxel rechallenge) was often proposed, and this chemotherapeutic agent showed to maintain antitumor activity in mCRPC patients. Docetaxel rechallenge may still constitute a valid treatment option mainly for patients with favorable response to first-line docetaxel, at least > 3 mo progression-free interval, age less than 75 years, good performance status, and acceptable docetaxel toxicity. The risk of cumulative toxicity must be evaluated, since sensory neuropathy, nail disorders and fatigue might occur on docetaxel rechallenge.

Rechallenge of docetaxel combined with epirubicin given on a weekly schedule in advanced castration-resistant prostate cancer patients previously exposed to docetaxel and abiraterone acetate: a single-institution experience

The aim of this paper was to evaluate the activity and tolerability of weekly docetaxel (D) combined with weekly epirubicin (EPI) in patients with advanced castrate-resistant prostate cancer (CRPC) previously exposed to D and abiraterone acetate (AA). Locally advanced or metastatic CRPC patients with 0-2 performance status, who had progressed after D and AA therapy, were included in the study. Previous treatment with chemotherapy agent cabazitaxel was also admitted. Treatment consisted of D 30 mg/m(2) intravenously (i.v.) and EPI 30 mg/m(2) i.v., every week (D/EPI). Chemotherapy was administered until disease progression or unacceptable toxicity. In our institution, twenty-six patients received D/EPI: their median age was 72 years (range 59-83 years). Twenty-three (88.5%) patients had bone metastases. A decrease in PSA levels ≥50% was observed in seven patients (26.9%, 95% CI: 0.11-0.47); of these, five had achieved a ≥50% PSA response during prior first-line D and six had achieved a PSA response during prior AA Among the subjects who were symptomatic at baseline, pain was reduced in nine patients (38.1%) with a significant decrease in analgesic use. Median progression-free survival was 4.4 months (95% CI, 3-5.2), and median overall survival was 10.7 months (95% CI, 8.9-18.4). Treatment was well tolerated and no grade 4 toxicities were observed. Our findings suggest that weekly D/EPI is feasible and active in heavily pretreated advanced CRPC patients and seem to support the hypothesis that the addition of EPI to D may lead to overcome the resistance to D in a subgroup of patients.

Rechallenge of docetaxel combined with epirubicin given on a weekly schedule in advanced castration-resistant prostate cancer patients previously exposed to docetaxel and abiraterone acetate: a single-institution experience

The aim of this paper was to evaluate the activity and tolerability of weekly docetaxel (D) combined with weekly epirubicin (EPI) in patients with advanced castrate-resistant prostate cancer (CRPC) previously exposed to D and abiraterone acetate (AA). Locally advanced or metastatic CRPC patients with 0-2 performance status, who had progressed after D and AA therapy, were included in the study. Previous treatment with chemotherapy agent cabazitaxel was also admitted. Treatment consisted of D 30 mg/m(2) intravenously (i.v.) and EPI 30 mg/m(2) i.v., every week (D/EPI). Chemotherapy was administered until disease progression or unacceptable toxicity. In our institution, twenty-six patients received D/EPI: their median age was 72 years (range 59-83 years). Twenty-three (88.5%) patients had bone metastases. A decrease in PSA levels ≥50% was observed in seven patients (26.9%, 95% CI: 0.11-0.47); of these, five had achieved a ≥50% PSA response during prior first-line D and six had achieved a PSA response during prior AA Among the subjects who were symptomatic at baseline, pain was reduced in nine patients (38.1%) with a significant decrease in analgesic use. Median progression-free survival was 4.4 months (95% CI, 3-5.2), and median overall survival was 10.7 months (95% CI, 8.9-18.4). Treatment was well tolerated and no grade 4 toxicities were observed. Our findings suggest that weekly D/EPI is feasible and active in heavily pretreated advanced CRPC patients and seem to support the hypothesis that the addition of EPI to D may lead to overcome the resistance to D in a subgroup of patients.

Trial watch: IDO inhibitors in cancer therapy

Indoleamine 2,3-dioxigenase 1 (IDO1) is the main enzyme that catalyzes the first, rate-limiting step of the so-called "kynurenine pathway", i.e., the metabolic cascade that converts the essential amino acid L-tryptophan (Trp) into L-kynurenine (Kyn). IDO1, which is expressed constitutively by some tissues and in an inducible manner by specific subsets of antigen-presenting cells, has been shown to play a role in the establishment and maintenance of peripheral tolerance. At least in part, this reflects the capacity of IDO1 to restrict the microenvironmental availability of Trp and to favor the accumulation of Kyn and some of its derivatives. Also, several neoplastic lesions express IDO1, providing them with a means to evade anticancer immunosurveillance. This consideration has driven the development of several IDO1 inhibitors, some of which (including 1-methyltryptophan) have nowadays entered clinical evaluation. In animal tumor models, the inhibition of IDO1 by chemical or genetic interventions is indeed associated with the (re)activation of therapeutically relevant anticancer immune responses. This said, several immunotherapeutic regimens exert robust clinical activity in spite of their ability to promote the expression of IDO1. Moreover, 1-methyltryptophan has recently been shown to exert IDO1-independent immunostimulatory effects. Here, we summarize the preclinical and clinical studies testing the antineoplastic activity of IDO1-targeting interventions.

Docetaxel: a review of its use for the first-line treatment of advanced castration-resistant prostate cancer

Docetaxel (Taxotere®) is a well established anti-mitotic chemotherapy agent. Among other therapeutic indications, docetaxel plus prednisone is indicated for first-line chemotherapy in patients with castration-resistant prostate cancer (CRPC). Docetaxel every 3 weeks plus continuous prednisone has been standard first-line chemotherapy in CRPC since demonstrating improved survival compared with the previous standard regimen, mitoxantrone plus prednisone, in the phase III TAX 327 trial in 2004. Since that time, docetaxel has been combined with various agents that demonstrated additive or synergistic activity in preclinical studies in an effort to further improve outcomes, but to date, overall survival has not been extended compared with docetaxel plus prednisone. However, several promising agents are emerging with a potential role in docetaxel-based combinations based on efficacy and manageable toxicity, including bevacizumab, dasatinib and atrasentan. In the TAX 327 trial, neutropenia was relatively common in the group receiving 3-weekly docetaxel plus prednisone, but infection was rare. The tolerability of a weekly docetaxel regimen also administered in this trial was not significantly different to that of the 3-weekly regimen, except for a lower incidence of grade 3 or 4 neutropenia. However, weekly or 2-weekly docetaxel administration schedules may have a place in very elderly or frail patients in order to improve tolerability compared with the 3-weekly regimen. In conclusion, docetaxel every 3 weeks plus prednisone remains the optimum first-line chemotherapy for most patients with advanced CRPC until such time that ongoing research with docetaxel and emerging therapeutic agents can demonstrate improved survival.

[Criteria and endpoints in advanced prostate cancer]

In castrate-refractory prostate cancers, main efficacy endpoints are progression free survival for phase-II trials and overall survival for phase-III trials. However, various progression criteria have been used, and overall survival may become more difficult to impact due to the recent approval of more effective drugs. PSA is useful in clinical practice, provided it is interpreted with caution, but cannot be used as a surrogate endpoint in clinical trials. Finally, circulating tumor cells represent a promising area of development.

Bevacizumab and weekly docetaxel in patients with metastatic castrate-resistant prostate cancer previously exposed to docetaxel

Background. The aim of this paper was to evaluate the activity and tolerability of docetaxel (D) and bevacizumab (Bev) in patients with metastatic castrate-resistant prostate cancer (CRPC) previously exposed to D. Methods. Treatment consisted of D 30 mg/m(2) i.v. for four consecutive weekly administrations followed by a 2-week rest interval, in addition to Bev 5 mg/kg i.v. every 2 weeks. Results. Forty-three patients were enrolled: a PSA response was observed in 27 patients (62.7%, 95% CI: 0.41 to 0.91), and a palliative response was achieved in 31 patients (72.1%, 95%CI: 0.48 to 1.02). After a median followup of 11.3 months, only five patients had died. The regimen was generally well tolerated. Conclusion. Weekly D + biweekly Bev seems to be an effective and well-tolerated treatment option for patients with metastatic CRPC previously exposed to D-based chemotherapy.