Tyme Technologies‘ SM-88 reduced the levels of circulating cancer cells — an indicator of metastatic disease — in all prostate cancer patients treated in an ongoing Phase 2 trial, according to data revealed at the European Society for Medical Oncology (ESMO) 2017 Congress, in Madrid, Spain.
The findings support the potential of SM-88 as a relatively non-toxic alternative to current standard of care — chemotherapy or androgen deprivation therapy (ADT) — in this subset of non-metastatic patients who had rising PSA levels, but no visible tumor.
The poster presentation was titled “Phase II Trial of SM-88 in Non-Metastatic Biochemical Recurrent Prostate Cancer” and presented by Giuseppe Del Priore, MD, chief medical officer at Tyme.
“Current standards of care for prostate cancer are associated with high toxicity and/or serious quality of life issues,” Del Priore said in a press release. “In fact, many urologists are starting to question the clinical benefits of ADT, which is associated with significant physiological and emotional side effects.”
SM-88, also known as TYME-88, is an investigational drug designed to target live cancer cells. It combines the chemistry of several well-known therapies to trigger multiple mechanisms that will kill cancer cells without affecting or involving surrounding healthy tissues.
The open-label, multi-center Phase 2 trial (NCT02796898) is enrolling up to 34 patients with biomarker-recurrent, non-metastatic prostate cancer who have increasing PSA levels and no detectable lesions. The patients will receive 230 mg of SM-88 daily, administrated orally, for up to six months. The trial is expected to conclude in the first half of 2018.
Preliminary data from the first nine patients who received SM-88 therapy for at least one month did not show signs of disease progression or severe adverse side effects. None of the patients required more toxic therapies, such as chemotherapy or chemical castration with ADT.
The number of circulating tumor cells (CTCs) was reduced by more than 20 percent in all patients, and by more than 60 percent in six patients. One patient had undetectable CTCs after 16 weeks of therapy.
SM-88 also improved PSA doubling time – a surrogate of disease progression – in seven patients. Testosterone levels also rose or remained stable, with patients reporting similar or better outcomes regarding intimacy.
“We are encouraged by the continued evidence of SM-88’s therapeutic potential as a relatively non-toxic alternative to radical treatments, such as potentially unnecessary chemical castration, and look forward to seeing additional data at the conclusion of this trial,” said Del Priore.