for males ages 18 years and up (full criteria)
at UC Davis
study started
estimated completion



The purpose of this trial is to investigate the safety and tolerability of TAS3681 and to find the maximum tolerated dose of TAS3681.

Official Title

A Phase 1, Open-Label, Non-Randomized, Safety, Tolerability and Pharmacokinetic Study of TAS3681 in Patients With Metastatic Castration Resistant Prostate Cancer


This is a first in human, multinational, phase 1, open-label study of TAS3681 in patients with metastatic castration resistant prostate cancer (mCRPC)evaluating safety, tolerability, pharmacokinetics and preliminary antitumor activity in patients with mCRPC for which there is no standard therapy. Eligible patients will either be enrolled in the dose escalation phase to evaluate safety and determine the maximum tolerated dose for TAS3681, including a preliminary evaluation of food effect, or the expansion phase in which additional cohorts of patients may be enrolled to further evaluate safety and preliminary efficacy of TAS3681 at the MTD or at a lower dose. Approximately 100 evaluable patients will be enrolled in the Dose Escalation Phase and approximately 100 patients will be enrolled in the Expansion Phase.


Metastatic Castration Resistant Prostate Cancer Prostate Cancer Prostatic Neoplasms TAS3681


You can join if…

Open to males ages 18 years and up

  1. Male > 18 years of age
  2. Histological or cytological evidence of metastatic castrate resistant prostate cancer with progression defined in PCWG3; Scher HI 2015 intolerance of standard chemotherapy
  3. ECOG performance status of < 1 on Day1 Cycle 1
  4. Ongoing androgen deprivation with serum testosterone < 50 ng/dl
  5. Ability to take medication orally
  6. Adequate organ function
  7. Willing to comply with scheduled visits and procedures

You CAN'T join if...

  1. QTc > 450ms, history of Qtc prolongation or predisposition for QTc prolongation or family history of sudden cardiac death or QT prolongation
  2. History or presence of heart failure or left ventricular dysfunction with ejection fraction < 40% within the previous 6 months; if >6 months cardiac function within normal limits and free of cardiac-related symptoms
  3. History or presence of atrial fibrillation , atrial flutter or paroxysmal supraventricular tachycardia; the presence or history of ventricular arrhythmias including ventricular fibrillation and ventricular tachycardia
  4. Presence of cardiac pacemaker or implantable cardioverter-defibrillator
  5. History or presence of bradycardia or conduction abnormalities
  6. History or presence of cardia arrest or unexplained syncope
  7. Hypokalemia
  8. History of myocardial infarction or severe unstable angina
  9. Any medication administered within 4 weeks prior to 1st dose of TAS3681 that is known to affect QT interval or arrhythmogenic
  10. . Serious illness or medical condition that could affect the safety or tolerability of study treatments
  11. . Received prior treatment of TAS3681
  12. . User of herbal products
  13. . Any condition or reason that in the opinion of the investigator, interferes with the ability of the patient to participate in the trial.
  14. . To be eligible to participate in the food effect assessment, patients must not have a history or presence of any clinically significant abnormality involving the gastrointestinal tract and an inability to fast for a minimum of 8 hours


  • Univeristy of California Davis Comprehensive Cancer Center accepting new patients
    Sacramento California 95817 United States
  • Seattle Cancer Care Alliance accepting new patients
    Seattle Washington 98109 United States


accepting new patients
Start Date
Completion Date
Taiho Oncology, Inc.
Phase 1
Study Type
Last Updated