Janssen's Zytiga Boosts Survival in Early-Stage Prostate Cancer

“Janssen has announced data from a post-hoc analysis of a Phase III trial showing that Zytiga plus prednisone boosted overall survival (OS) by 11.8 months compared with placebo plus prednisone, in men with early and less aggressive metastatic castration-resistant prostate cancer (mCRPC) who had not received chemotherapy.

“Data presented today at the European Association of Urology (EAU) 2016 Congress in Munich, Germany, demonstrated that in the COU-AA-302 trial, Zytiga (abiraterone acetate) increased OS to 53.6 months versus the 41.8 months achieved by patients treated with prednisone alone. This benefit was shown to be 4.4 greater than that previously reported for the combo in the final analysis of the COU-AA-302 trial in 2014.

“The post-hoc analysis divided patients into two groups to identify which group experienced a greater treatment benefit. The patients in group 1 were in an earlier, less advanced and less symptomatic stage of the disease, while those in group 2 were in a later, more advanced and more symptomatic stage of the disease.”


Abituzumab Improves Bone Lesion Progression, not PFS in CRPC

“Abituzumab did not extend progression-free survival (PFS) compared with placebo in a phase II study of patients with metastatic castration-resistant prostate cancer. The agent did, however, offer a lower incidence of bone lesion progression, and researchers say it still warrants further investigation.

“Previous research has suggested that integrins play a role in the progression of metastatic prostate cancer and associated bone lesions, wrote researchers led by Maha Hussain, MB, ChB, of the University of Michigan in Ann Arbor. Abituzumab is a pan-αv integrin inhibitor; a phase I trial previously showed that the agent has activity in patients with castration-resistant prostate cancer and bone metastases.

“The new phase II trial randomized 180 patients between three arms: a 750-mg abituzumab group, a 1,500-mg abituzumab group, or placebo. All groups also received standard of care. The results were published in Clinical Cancer Research.”


FDA Grants Olaparib Breakthrough Designation in mCRPC

“Olaparib (Lynparza) has received an FDA breakthrough therapy designation as a treatment for patients with BRCA1/2 or ATM-mutated metastatic castration-resistant prostate cancer (mCRPC) in those who have received a prior taxane-based chemotherapy and at least either hormonal agent enzalutamide (Xtandi) or abiraterone acetate (Zytiga).

“The designation, which will accelerate the development and review of the first-in-class oral PARP inhibitor, is based on data from the phase II TOPARP-A trial that demonstrated that olaparib monotherapy had an overall response rate (ORR) of nearly 90% in a biomarker-defined subgroup of patients who had DNA-repair defects.


Radium-223 Benefits Survival, Not Just for Palliative Care

“Despite what many believe, not all radiopharmaceuticals are just for pain palliation, says Phillip J. Koo, MD, a radiologist of Memorial Hospital and University of Colorado Hospital.

“The ALSYMPCA trial, which was the basis for the 2013 FDA approval of radium-223 dichloride (Xofigo) showed a median overall survival (OS) of 14 months with radium-223 versus 11.2 months with placebo (HR, 0.70; P = .00185) in patients with metastatic castration-resistant prostate cancer (mCRPC).

“Despite the fact that it has been 3 years since the pivotal ALSYMPCA trial and the coinciding FDA approval, many oncologists still need to be educated regarding radium-223’s benefits, says Koo.”


Phase III Trial of Drug Custirsen in Prostate Cancer Produces Positive Interim Results

The gist: A clinical trial is currently testing a drug called custirsen in men with metastatic, castration-resistant prostate cancer (CRPC). The patients are receiving custirsen along with the chemotherapy drug cabazitaxel. The trial recently underwent a “futility analysis” to ensure it could continue as planned. Final results will be announced later this year or in 2016.

“OncoGenex Pharmaceuticals, Inc. (OGXI) today announced that the AFFINITY trial is continuing as planned based upon completion of the interim futility analysis and the recommendation of the Independent Data Monitoring Committee (IDMC).

“The Phase 3 AFFINITY trial is designed to evaluate a survival benefit for custirsen in combination with second-line cabazitaxel chemotherapy in 635 men with metastatic castrate-resistant prostate cancer (CRPC). AFFINITY is being conducted at 95 global clinical trial sites and final survival results are expected to be announced in late 2015 or early 2016.

” ‘While the results remain blinded to OncoGenex, we are very pleased that the AFFINITY trial has passed this interim futility analysis and we remain confident in the potential value of custirsen in treating cancer, particularly in patients who have advancing disease despite previous treatments,’ said Scott Cormack, President and CEO of OncoGenex.”


Enzalutamide Improved Health-Related Quality of Life in Prostate Cancer

Editor’s note: This article discusses the results of a clinical trial—a research study with volunteer patients. All patients who participated in the trial had metastatic castration-resistant prostate cancer that had worsened during treatment with the chemotherapy drug docetaxel. The study found that treatment with the drug enzalutamide reduced symptoms and improved quality of life for the patients.

“Enzalutamide was associated with significant improvements in disease-related symptoms and all aspects of health-related quality of life among men with metastatic castration-resistant prostate cancer, according to results of the phase 3, double blind AFFIRM trial.

“The trial included 1,199 patients who progressed during treatment with docetaxel.

Karim Fizazi, MD, PhD, medical oncologist in the department of cancer medicine at Institut Gustave Roussy at the University of Paris, and colleagues randomly assigned 800 patients to 160 mg daily enzalutamide (Xtandi; Astellas, Medivation). The other 399 patients received placebo.”


New Androgen Receptor Inhibitor Shows Activity in Metastatic Castration-Resistant Prostate Cancer

The gist: Some patients have what is known as metastatic “castration-resistant” prostate cancer (mCRPC)—metastatic cancer that worsens despite treatment with traditional hormone therapy. Researchers are hard at work to discover solutions for these treatment-resistant cancers. A recent clinical trial with volunteer mCRPC patients tested a new treatment called ODM-201. The treatment appeared to be safe, and men who took it had promising decreases in their PSA levels. Further testing is needed to see how effective ODM-201 might be in treating mCRPC.

“ODM-201 is a novel androgen receptor inhibitor—structurally distinct from enzalutamide (Xtandi)—that acts via high-affinity binding to the androgen receptor and inhibition of receptor nuclear translocation. In the phase I/II ARADES trial reported in The Lancet Oncology, Fizazi et al identified no maximum tolerated dose and observed prostate-specific antigen (PSA) responses in men with progressive metastatic castration-resistant prostate cancer…

“In this study, conducted in 23 U.S. and European hospitals, no dose-limiting toxicity or maximum tolerated dose was found at an oral ODM-201 dose range of 200 mg to 1,800 mg daily in the phase I portion.  In the phase II portion, 110 patients were randomly assigned to receive doses of 200 mg (n =38), 400 mg (n = 37), or 1,400 mg (n = 35); four, seven, and three patients treated at these dose levels in the phase I portion were also advanced to phase II evaluation. The primary endpoint was ≥ 50% reduction in serum PSA at week 12…

“Among evaluable patients, PSA response at 12 weeks was observed in 29% at 200 mg, 33% at 400 mg, and 33% at 1,400 mg. Response rates were higher among patients who were chemotherapy-naive and had not received CYP17 inhibitor treatment (50%, 69%, and 86%). Follow-up is ongoing.”


The Pitfalls of Androgen Deprivation Therapy


For men with advanced prostate cancer, androgen deprivation therapy (ADT) is usually the initial treatment of choice. ADT slows the growth of prostate tumors and can even make them shrink. But unfortunately, the results of ADT are short-lived; tumors can develop resistance to ADT and grow back, sometimes stronger than before. Scientists are hard at work to figure out the underlying mechanisms of ADT resistance and how to bypass it. Continue reading…


Targeting Amino Acid Transport in Metastatic Castration-Resistant Prostate Cancer: Effects on Cell Cycle, Cell Growth, and Tumor Development

“Background: L-type amino acid transporters (LATs) uptake neutral amino acids including L-leucine into cells, stimulating mammalian target of rapamycin complex 1 signaling and protein synthesis. LAT1 and LAT3 are overexpressed at different stages of prostate cancer, and they are responsible for increasing nutrients and stimulating cell growth. Methods: We examined LAT3 protein expression in human prostate cancer tissue microarrays. LAT function was inhibited using a leucine analog (BCH) in androgen-dependent and -independent environments, with gene expression analyzed by microarray. A PC-3 xenograft mouse model was used to study the effects of inhibiting LAT1 and LAT3 expression. Results were analyzed with the Mann-Whitney U or Fisher exact tests. All statistical tests were two-sided…Conclusion: Inhibition of LAT transporters may provide a novel therapeutic target in metastatic castration-resistant prostate cancer, via suppression of mammalian target of rapamycin complex 1 activity and M-phase cell cycle genes.”