“The use of bipolar androgen therapy (BAT), involving rapid cycling between high and low serum concentrations, was safe and resulted in responses and resensitization to enzalutamide in men with metastatic castration-resistant prostate cancer (CRPC) who progressed after initial enzalutamide therapy, according to a new study.
“ ‘Clinically, metastatic CRPC that has progressed after enzalutamide treatment is minimally responsive to further therapy that inhibits androgen receptor signaling,’ wrote study authors led by Benjamin A. Teply, MD, of Johns Hopkins School of Medicine in Baltimore. ‘Theoretically, rapidly varying the androgen concentrations between the extremes of supraphysiological and near-castrate, a strategy termed BAT, provides insufficient time for CRPC cells to adaptively regulate androgen receptor concentrations,’ and thus may promote cancer cell death and prevent resistance.”
“Munich, Germany: A strategy of alternately flooding and starving the body of testosterone is producing good results in patients who have metastatic prostate cancer that is resistant to treatment by chemical or surgical castration, according to new findings.
“In a presentation at the 28th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics in Munich, Germany, today (Thursday), researchers reported that results from 47 men who have completed at least three cycles of bipolar androgen therapy (BAT) showed that the strategy was safe and effective. Prostate specific antigen (PSA) levels fell in the majority of the men, tumours shrank in some men, in several the disease did not progress and this included some whose disease continued to be stable for more than a year. One man appears to have been ‘cured’, in that his PSA levels dropped to zero after three months and have remained so for 22 cycles of treatment, with no trace of the disease remaining. The researchers are planning to treat a group of 60 men in total.”
“Preliminary data suggest that a new twist on manipulating hormones in prostate cancer shows some benefit. The standard approach to treatment is androgen deprivation therapy (ADT), but the new approach intersperses this with bipolar androgen therapy (BAT) with intramuscular testosterone injections.
“Results from a small phase 2 study in 29 men with advanced hormone-sensitive prostate cancer show that the primary endpoint was met, with nearly 60% of men achieving a prostate-specific antigen (PSA) level <4 ng/mL after undergoing two cycles of BAT.
“The findings, which were presented at Genitourinary Cancers Symposium (GUCS) 2016, also suggest that BAT may have a positive impact on quality of life.”
“Conventional wisdom has it that high levels of testosterone help prostate cancers grow.”However, a new, small study suggests that a treatment strategy called bipolar androgen therapy—where patients alternate between low and high levels of testosterone—might make prostate tumors more responsive to standard hormonal therapy.
“As the researchers explained, the primary treatment for advanced prostate cancer is hormonal therapy, which lowers levels of testosterone to prevent the tumor from growing. But there’s a problem: Prostate cancer cells inevitably overcome the therapy by increasing their ability to suck up any remaining testosterone in the body.
“The new strategy forces the tumor to respond again to higher testosterone levels, helping to reverse its resistance to standard therapy, the researchers say.
“If confirmed in several ongoing larger trials, ‘this could lead to a new treatment approach’ for prostate cancers that have grown resistant to hormonal therapy, said lead researcher Dr. Michael Schweizer, an assistant professor of oncology at the University of Washington School of Medicine in Seattle.”