Effect of docetaxel added to bicalutamide in Hormone-Naïve non-metastatic prostate cancer with rising PSA, a randomized clinical trial (SPCG-14).

BACKGROUND: Historically, endocrine therapy was used in a range of scenarios in patients with rising PSA, both as a treatment for locally advanced non-metastatic prostate cancer and PSA recurrence following curative intended therapy. In the present study the objective was to investigate if chemotherapy added to endocrine therapy could improve progression-free survival (PFS). MATERIALS AND METHODS: Patients with hormone-naïve, non-metastatic prostate cancer and rising prostate-specific antigen (PSA), enrolled from Sweden, Denmark, the Netherlands, and Finland, were randomized to long-term bicalutamide (150 mg daily) or plus docetaxel (75 mg/m2, q3w, 8-10 cycles) without prednisone, after stratification for the site, prior local therapy or not, and PSA doubling time. The primary endpoint was 5-year PFS analyzed with a stratified Cox proportional hazards regression model on intention to treat basis. RESULTS: Between 2009 and 2018, a total of 348 patients were randomized; 315 patients had PSA relapse after radical treatment, 33 patients had no prior local therapy. Median follow-up was 4.9 years (IQR 4.0-5.1). Adding docetaxel improved PFS (HR 0.68, 95% CI 0.50-0.93; p = 0.015). Docetaxel showed an advantage for patients with PSA relapse after prior local therapy (HR 0.67, 95% CI 0.49-0.94; p = 0.019). One event of neutropenic infection/fever occurred in 27% of the patients receiving docetaxel. Limitations were slow recruitment, lack of enrolling patients without radical local treatment, and too short follow-up for evaluation of overall survival in patients with PSA relapse. CONCLUSION: Docetaxel improved PFS in patients starting bicalutamide due to PSA relapse after local therapy or localized disease without local therapy. Confirmatory studies of the efficacy of docetaxel in the setting of PSA-only relapse in addition to endocrine therapies may be justified if longer follow-up will show increased metastatic-free survival.

Ilixadencel, a Cell-based Immune Primer, plus Sunitinib Versus Sunitinib Alone in Metastatic Renal Cell Carcinoma: A Randomized Phase 2 Study.

Background: The prognosis of patients with synchronous metastatic renal cell carcinoma (mRCC) is poor. Whereas single-agent tyrosine kinase inhibition (TKI) is clearly insufficient, the effects can be enhanced by combinations with immune checkpoint inhibitors. Innovative treatment options combining TKI and other immune-stimulating agents could prove beneficial. Objective: To evaluate the clinical effects on metastatic disease when two doses of allogeneic monocyte-derived dendritic cells (ilixadencel) are administrated intratumorally followed by nephrectomy and treatment with sunitinib compared with nephrectomy and sunitinib monotherapy, in patients with synchronous mRCC. Design setting and participants: A randomized (2:1) phase 2 multicenter trial enrolled 88 patients with newly diagnosed mRCC to treatment with the combination ilixadencel/sunitinib (ILIXA/SUN; 58 patients) or sunitinib alone (SUN; 30 patients). Outcome measurements and statistical analysis: The primary endpoints were 18-mo survival rate and overall survival (OS). A secondary endpoint was objective response rate (ORR) assessed up to 18 mo after enrollment. Statistic evaluations included Kaplan-Meier estimates, log-rank tests, Cox regression, and stratified Cochran-Mantel-Haenszel tests. Results and limitations: The median OS was 35.6 mo in the ILIXA/SUN arm versus 25.3 mo in the SUN arm (hazard ratio 0.73, 95% confidence interval 0.42-1.27; p = 0.25), while the 18-mo OS rates were 63% and 66% in the ILIXA/SUN and SUN arms, respectively. The confirmed ORR in the ILIXA/SUN arm were 42.2% (19/45), including three patients with complete response, versus 24.0% (six/25) in the SUN arm (p = 0.13) without complete responses. The study was not adequately powered to detect modest differences in survival. Conclusions: The study failed to meet its primary endpoints. However, ilixadencel in combination with sunitinib was associated with a numerically higher, nonsignificant, confirmed response rate, including complete responses, compared with sunitinib monotherapy. Patient summary: We studied the effects of intratumoral vaccination with ilixadencel followed by sunitinib versus sunitinib only in a randomized phase 2 study. The combination treatment showed numerically higher numbers of confirmed responses, suggesting an immunologic effect.

Castration is a prerequisite for the inhibitory effect of metronomic chemotherapy on the growth of experimental castration-resistant prostate cancer.

BACKGROUND: Low-dose metronomic chemotherapy (LDMC) is an alternative for treatment of patients with late-stage prostate cancer (PC) not susceptible to regular chemotherapy due to its severe side effects. The exact working mechanisms of LDMC have not been established, although anti-angiogenic effects have been identified. In PC, several studies show clinical effects from LDMC but the mode of action and the role of androgen signaling for its effect are not known. In this study, we used a xenograft model to evaluate the effect of LDMC on PC growth in relation to androgen deprivation. MATERIAL AND METHODS: Subcutaneous human castration-resistant PC xenografts were treated with LDMC using cyclophosphamide (CPA). Treatment effect was compared to treatment with maximum tolerated dose (MTD) and also between intact and castrated mice. Microvessel density (MVD), and factors important for angiogenesis were analyzed with immunohistochemistry and real-time-PCR. RESULTS: Tumors treated with LDMC were 50% smaller than untreated controls. Tumors in non-castrated mice were not affected by LDMC, but in an androgen receptor (AR) negative tumor model, tumor inhibiting effect were seen in both intact and castrated animals, indicating mechanism via AR. MTD resulted in similar growth inhibition as LDMC in castrated mice, but resulted in severe weight loss. Despite that LDMC induced TSP1 mRNA expression, and the hypoxic area in the tumors was slightly increased, no decrease in MVD was detected. CONCLUSIONS: This study shows that a low-dose metronomic scheduling of CPA was as efficient as MTD treatment, and resulted in fewer side effects. It also demonstrates that a functional androgen signaling axis inhibits this effect despite the castration-resistance of the tumor cells. The anti-angiogenic nature of the effect of LDMC could not be confirmed and further studies to elucidate the working mechanism for treatment response are needed.

Effective oral combination metronomic chemotherapy with low toxicity for the management of castration-resistant prostate cancer.

Prostate cancer (PC) was previously believed to be a chemoresistant disease. In recent years taxane-based chemotherapy has been shown to prolong survival in patients with castration-resistant prostate cancer (CRPC). It remains to be shown, however, which type of chemotherapy provides the most beneficial effect with the least amount of side effects. Seventeen patients with chemonaive CRPC were enrolled in a pilot study evaluating an orally administered chemo-hormonal treatment regimen using a weekly sequential combination called KEES; consisting of ketoconazole in combination with cyclophosphamide or etoposide in combination with estramustine administered on alternate weeks. Prednisone was administered throughout the treatment period. Prostate-specific antigen (PSA) response and acute and chronic toxicities were evaluated. Seventeen patients with CRPC were treated; eleven patients demonstrated a median reduction in PSA of 87% (range 26-99%). Ten (59%) patients responded with a decrease in PSA >50%. Thrombocytopenia and anaemia were the most common side effects. One study fatality was reported, however, it was unclear whether this was treatment related. In conclusion, KEES may be a promising option for patients with CRPC, resulting in a clear reduction in PSA with limited toxicity. Further clinical evaluation of this metronomic chemohormonal combination is underway.