Therapeutic prostate-specific antigen (PSA) -targeted poxviral vaccines for prostate cancer have been well tolerated. PROSTVAC-VF treatment was evaluated for safety and for prolongation of ...progression-free survival (PFS) and overall survival (OS) in a randomized, controlled, and blinded phase II study.
In total, 125 patients were randomly assigned in a multicenter trial of vaccination series. Eligible patients had minimally symptomatic castration-resistant metastatic prostate cancer (mCRPC). PROSTVAC-VF comprises two recombinant viral vectors, each encoding transgenes for PSA, and three immune costimulatory molecules (B7.1, ICAM-1, and LFA-3). Vaccinia-based vector was used for priming followed by six planned fowlpox-based vector boosts. Patients were allocated (2:1) to PROSTVAC-VF plus granulocyte-macrophage colony-stimulating factor or to control empty vectors plus saline injections.
Eighty-two patients received PROSTVAC-VF and 40 received control vectors. Patient characteristics were similar in both groups. The primary end point was PFS, which was similar in the two groups (P = .6). However, at 3 years post study, PROSTVAC-VF patients had a better OS with 25 (30%) of 82 alive versus 7 (17%) of 40 controls, longer median survival by 8.5 months (25.1 v 16.6 months for controls), an estimated hazard ratio of 0.56 (95% CI, 0.37 to 0.85), and stratified log-rank P = .0061.
PROSTVAC-VF immunotherapy was well tolerated and associated with a 44% reduction in the death rate and an 8.5-month improvement in median OS in men with mCRPC. These provocative data provide preliminary evidence of clinically meaningful benefit but need to be confirmed in a larger phase III study.
We investigated the safety and efficacy (response rates, time to disease progression, survival) of trastuzumab, carboplatin, gemcitabine, and paclitaxel in advanced urothelial carcinoma patients and ...prospectively evaluated human epidermal growth factor receptor-2 (Her-2/neu) overexpression rates.
Advanced urothelial carcinoma patients were screened for Her-2/neu overexpression. Eligibility for therapy required human epidermal growth factor receptor-2 (Her-2/neu) overexpression by immunohistochemistry (IHC), gene amplification and/or elevated serum Her-2/neu, no prior chemotherapy for metastasis, and adequate organ function including a normal cardiac function. Treatment consisted of trastuzumab (T) 4 mg/kg loading dose followed by 2 mg/kg on days 1, 8, and 15; paclitaxel (P) 200 mg/m2 on day 1; carboplatin (C; area under the curve, 5) on day 1; and gemcitabine (G) 800 mg/m2 on days 1 and 8. The primary end point was cardiac toxicity.
Fifty-seven (52.3%) of 109 registered patients were Her-2/neu positive, and 48.6% were positive by IHC. Her-2/neu-positive patients had more metastatic sites and visceral metastasis than did Her-2/neu negative patients. Forty-four of 57 Her-2/neu-positive patients were treated with TPCG. The median number of cycles was six (range, 1 to 12 cycles). The most common grade 3/4 toxicity was myelosuppression. Grade 3 sensory neuropathy occurred in 14% of patients, and 22.7% experienced grade 1 to 3 cardiac toxicity (grade 3, n = 2: one left ventricular dysfunction, one tachycardia). There were three corrected therapy-related deaths. Thirty-one (70%) of 44 patients responded (five complete and 26 partial), and 25 (57%) of 44 were confirmed responses. Median time to progression and survival were 9.3 and 14.1 months, respectively.
We prospectively characterized Her-2/neu status in advanced urothelial carcinoma patients. TPCG is feasible; cardiac toxicity rates were higher than projected, but the majority were grade two or lower. Determining the true contribution of trastuzumab requires a randomized trial.
Purpose Patients with high-risk prostate cancer after radical prostatectomy are at risk for death. Adjuvant androgen-deprivation therapy (ADT) may reduce this risk. We hypothesized that the addition ...of mitoxantrone and prednisone (MP) to adjuvant ADT could reduce mortality compared with adjuvant ADT alone. Methods Eligible patients had cT1-3N0 prostate cancer with one or more high-risk factors after radical prostatectomy (Gleason score GS ≥ 8; pT3b, pT4, or pN+ disease; GS 7 and positive margins; or preoperative prostate-specific antigen PSA > 15 ng/mL, biopsy GS score > 7, or PSA > 10 ng/mL plus biopsy GS > 6. Patients with PSA ≤ 0.2 ng/mL after radical prostatectomy were stratified by pT/N stage, GS, and adjuvant radiation plan and randomly assigned to ADT (bicalutamide and goserelin for 2 years) or ADT plus six cycles of MP. The primary end point was overall survival (OS). Median OS was projected to be 10 years in the ADT arm, requiring 680 patients per arm to detect a hazard ratio of 1.30 with 92% power and one-sided α = .05. Results Nine hundred sixty-one eligible intent-to-treat patients were randomly assigned to ADT or ADT + MP from October 1999 to January 2007, when the Data Safety Monitoring Committee recommended stopping accrual as a result of higher leukemia incidence with ADT + MP. Median follow-up was 11.2 years. The 10-year OS estimates were 87% with ADT (expected 50%) and 86% with ADT + MP (hazard ratio, 1.06; 95% CI, 0.79 to 1.43). The 10-year estimate for disease-free survival was 72% for both arms. Prostate cancer was the cause of death in 18% of patients in the ADT arm and 22% in the ADT + MP arm. More patients in the MP arm died of other cancers (36% v 18% in ADT alone arm). Conclusion MP did not improve OS and increased deaths from other malignancies. The DFS and 10-year OS in these patients treated with 2 years of ADT were encouraging compared with historical estimates, although a definitive conclusion regarding value of ADT may not be made without a nontreatment control arm.
Prostate cancer is the most commonly diagnosed malignancy among Western men and accounts for the second leading cause of cancer-related deaths. Prostate cancer tends to grow slowly and recent studies ...suggest that it relies on lipid fuel more than on aerobic glycolysis. However, the biochemical mechanisms governing the relationships between lipid synthesis, lipid utilization, and cancer growth remain unknown. To address the role of lipid metabolism in prostate cancer, we have used etomoxir and orlistat, clinically safe drugs that block lipid oxidation and lipid synthesis/lipolysis, respectively. Etomoxir is an irreversible inhibitor of the carnitine palmitoyltransferase (CPT1) enzyme that decreases β oxidation in the mitochondria. Combinatorial treatments using etomoxir and orlistat resulted in synergistic decreased viability in LNCaP, VCaP, and patient-derived benign and prostate cancer cells. These effects were associated with decreased androgen receptor expression, decreased mTOR signaling, and increased caspase-3 activation. Knockdown of CPT1A enzyme in LNCaP cells resulted in decreased palmitate oxidation but increased sensitivity to etomoxir, with inactivation of AKT kinase and activation of caspase-3. Systemic treatment with etomoxir in nude mice resulted in decreased xenograft growth over 21 days, underscoring the therapeutic potential of blocking lipid catabolism to decrease prostate cancer tumor growth.
Sipuleucel-T, an autologous cellular immunotherapy, was investigated in a randomized, double-blind, controlled trial to determine its biologic activity in androgen-dependent prostate cancer (ADPC).
...Patients with prostate cancer detectable by serum prostate-specific antigen (PSA) following radical prostatectomy received 3 to 4 months of androgen suppression therapy, and were then randomized (2:1) to receive sipuleucel-T (n = 117) or control (n = 59). The primary endpoint was time to biochemical failure (BF) defined as serum PSA ≥ 3.0 ng/mL. PSA doubling time (PSADT), time to distant failure, immune response, and safety were also evaluated.
Median time to BF was 18.0 months for sipuleucel-T and 15.4 months for control (HR = 0.936, P = 0.737). Sipuleucel-T patients had a 48% increase in PSADT following testosterone recovery (155 vs. 105 days, P = 0.038). With only 16% of patients having developed distant failure, the treatment effect favored sipuleucel-T (HR = 0.728, P = 0.421). The most frequent adverse events in sipuleucel-T patients were fatigue, chills, and pyrexia. Immune responses to the immunizing antigen were greater in sipuleucel-T patients at Weeks 4 and 13 (P < 0.001, all) and were sustained prior to boosting as measured in a subset of patients a median of 22.6 months (range: 14.3-67.3 months) following randomization.
No significant difference in time to BF could be shown. The finding of increased PSADT in the sipuleucel-T arm is consistent with its biologic activity in ADPC. Long-term follow-up will be necessary to determine if clinically important events, such as distant failure, are affected by therapy. Treatment was generally well tolerated.
Background: Plant derivatives have been studied as therapies for prostate cancer based on their purported anti-inflammatory and antioxidant properties and low toxicities. The acai berry is an example ...of a plant rich in phytochemicals, which may slow the growth of prostate cancer. Methods: This was a phase II, Simon 2-stage clinical trial in patients with biochemically recurrent prostate cancer with a primary endpoint of prostate-specific antigen (PSA) response. Patients were asymptomatic, with a rising PSA of at least 0.2 ng/mL, and were treated with twice daily intake of Acai Juice Product until PSA progression, with a primary endpoint of PSA response. Results: Twenty-one patients were enrolled in the first stage of the trial. One of those patients had a PSA response within the study time period. The PSA doubling time was lengthened in 71% of patients (95% confidence interval = 48% to 89%) on the trial, and in a small number of responders, this was sustained over an extended time. Conclusions: This study did not meet its primary endpoint of 50% PSA response. Nevertheless, the overall tolerability and effects on PSA stabilization warrant further exploration in a biochemically recurrent population.
Bladder cancer is the fourth and eighth most common cancer in men and women in the USA, respectively. Flavonoid phytochemicals are being studied for both prevention and therapy of various human ...malignancies including bladder cancer. One such naturally occurring flavonoid is silibinin isolated from milk thistle. Here, we assessed the effect of silibinin on human bladder transitional cell carcinoma (TCC) cell growth, cell cycle modulation and apoptosis induction, and associated molecular alterations, employing two different cell lines representing high-grade invasive tumor (TCC-SUP) and high-grade TCC (T-24) human bladder cancer. Silibinin treatment of these cells resulted in a significant dose- and time-dependent growth inhibition together with a G1 arrest only at lower doses in TCC-SUP cells but at both lower and higher doses in T-24 cells; higher silibinin dose showed a G2/M arrest in TCC-SUP cells. In other studies, silibinin treatment strongly induced the expression of Cip1/p21 and Kip1/p27, but resulted in a decrease in cyclin-dependent kinases (CDKs) and cyclins involved in G1 progression. Silibinin treatment also showed an increased interaction between cyclin-dependent kinase inhibitors (CDKIs)–CDKs and a decreased CDK kinase activity. Further, the G2/M arrest by silibinin in TCC-SUP cells was associated with a decrease in pCdc25c (Ser216), Cdc25c, pCdc2 (Tyr15), Cdc2 and cyclin B1 protein levels. In additional studies, silibinin showed a dose- and a time-dependent apoptotic death only in TCC-SUP cells that was associated with cleaved forms of caspase 3 and poly(ADP-ribose) polymerase. Together, these results suggest that silibinin modulates CDKI–CDK–cyclin cascade and activates caspase 3 causing growth inhibition and apoptotic death of human TCC cells, providing a strong rationale for future studies evaluating preventive and/or intervention strategies for silibinin in bladder cancer pre-clinical models.
Men with high-risk features (extraprostatic extension or high Gleason grade) face a high risk of prostate cancer recurrence after radical prostatectomy. Clinical trials of adjuvant systemic therapy ...for such patients have been limited.
The SWOG (Southwest Oncology Group) S9921 study randomly assigned 983 men with high-risk features at prostatectomy to receive adjuvant therapy with androgen deprivation (ADT) alone or in combination with mitoxantrone chemotherapy. ADT consisted of goserelin and bicalutamide for 2 years.
Although the final primary treatment comparison results are not ready for publication, this article reports results in the ADT-alone control arm with a median follow-up of 4.4 years. For these 481 men, the estimated 5-year biochemical failure-free survival is 92.5% (95% CI, 90 to 95), and 5-year overall survival is 95.9% (95% CI, 93.9 to 97.9).
The results of this trial, taken in context, make a compelling argument for counseling all high-risk patients with prostate cancer about adjuvant ADT. This article discusses the challenges in the design and implementation of clinical trials to take the next step forward in adjuvant therapy for prostate cancer because of the excellent survival achieved with currently available therapies and highlights the need for better molecular markers to personalize care.
Silibinin is a polyphenolic flavonoid isolated from milk thistle with anti-neoplastic activity in several in vitro and in vivo models of cancer, including prostate cancer. Silybin-phytosome is a ...commercially available formulation containing silibinin. This trial was designed to assess the toxicity of high-dose silybin-phytosome and recommend a phase II dose. Silybin-phytosome was administered orally to prostate cancer patients, giving 2.5-20 g daily, in three divided doses. Each course was 4 weeks in duration. Thirteen patients received a total of 91 courses of silybin-phytosome. Baseline patient characteristics included: median age of 70 years, median baseline prostate specific antigen (PSA) of 4.3 ng/ml, and a median ECOG performance status of 0. The most prominent adverse event was hyperbilirubinemia, with grade 1-2 bilirubin elevations in 9 of the 13 patients. The only grade 3 toxicity observed was elevation of alanine aminotransferase (ALT) in one patient; no grade 4 toxicity was noted. No objective PSA responses were observed. We conclude that 13 g of oral silybin-phytosome daily, in 3 divided doses, appears to be well tolerated in patients with advanced prostate cancer and is the recommended phase II dose. Asymptomatic liver toxicity is the most commonly seen adverse event.
Purpose
Prostate cancer (PCa) is the second most common cause of cancer-related death among men in the United States. Due to the lipid-driven metabolic phenotype of PCa, imaging with 2-deoxy-2-
18
...Ffluoro-
d
-glucose (
18
FFDG) is suboptimal, since tumors tend to have low avidity for glucose.
Procedures
We have used the fat oxidation inhibitor etomoxir (2-6-(4-chlorophenoxy)-hexyloxirane-2-carboxylate) that targets carnitine-palmitoyl-transferase-1 (CPT-1) to increase glucose uptake in PCa cell lines. Small hairpin RNA specific for CPT1A was used to confirm the glycolytic switch induced by etomoxir
in vitro
. Systemic etomoxir treatment was used to enhance
18
FFDG-positron emission tomography (
18
FFDG-PET) imaging in PCa xenograft mouse models in 24 h.
Results
PCa cells significantly oxidize more of circulating fatty acids than benign cells via CPT-1 enzyme, and blocking this lipid oxidation resulted in activation of the Warburg effect and enhanced
18
FFDG signal in PCa mouse models.
Conclusions
Inhibition of lipid oxidation plays a major role in elevating glucose metabolism of PCa cells, with potential for imaging enhancement that could also be extended to other cancers.
PDF
