This trial is testing whether molecularly targeted oral medications called talazoparib and
tazemetostat can be safely combined for the treatment of prostate cancer, and whether the
combination is effective in shrinking or preventing the growth of metastatic prostate cancer.
The names of the study drugs involved in this study are:
This is a Phase 1a/1b clinical trial to assess safety, tolerability and preliminary clinical
activity of the combination of talazoparib with tazemetostat in metastatic
castration-resistant prostate cancer (mCRPC) patients.
The U.S. Food and Drug Administration (FDA) has not approved talazoparib or tazemetostat for
metastatic castration-resistant prostate cancer (mCRPC) but they have been approved for other
uses. Talazoparib has been approved for use in breast cancer, and tazemetostat has been
approved for use in certain types of sarcoma and lymphoma.
Talazoparib is an orally administered molecularly targeted chemotherapy drug called a "PARP
inhibitor", which acts to block the ability of cancer cells to repair certain forms of damage
to their DNA - the accumulation of damaged DNA causes certain cancer cells to die. Other PARP
inhibitors are already approved for use in prostate cancer patients with specific gene
mutations detected in their blood or in their cancer, and talazoparib is currently being
studied for treatment of prostate cancer in other clinical trials.
Tazemetostat is an orally administered molecularly targeted chemotherapy drug called an "EZH2
inhibitor", which acts to block the production of proteins encoded by DNA in the cancer cells
that are important in cancer growth and survival. Tazemetostat is also being studied for the
treatment of prostate cancer in other clinical trials. In the laboratory setting,
tazemetostat causes changes in protein levels in prostate cancer cells that make them
sensitive to dying in the presence of PARP inhibitors.
The research study procedures include screening for eligibility and study treatment including
evaluations and follow up visits.
The study design involves two parts. The first part is called the "dose escalation" to find a
safe dose for the combination of talazoparib and tazemetostat. The second part is called the
"dose expansion" where additional participants are treated at the safe dose identified in the
first part of the study.
Participants will receive study treatment for as long as they do not have serious side
effects and their disease does not get worse. Participants will be followed after completion
of study treatment for up to 24 months.
It is expected that about 38 people will take part in this research study.
Funding for this research is provided by a grant awarded by the non-profit Prostate Cancer
Foundation along with Pfizer, Inc. In addition, Pfizer is supporting the study by providing
the study drug talazoparib. Epizyme, Inc. is supporting the study by providing the study drug
Metastatic Prostate Cancer, Metastatic Castration-resistant Prostate Cancer
If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.
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