June 5 (Reuters) - Sierra Oncology Inc
* Sierra oncology reports encouraging initial progress from ongoing phase 1 clinical trials of chk1 inhibitor sra737
* Sierra oncology inc says sra737 has been well-tolerated to date
* Sierra oncology inc - "no grade 2 or higher sra737-related adverse events have been reported"
* Sierra oncology inc says for phase 1 chemotherapy combination study, has concluded enrolment and study has transitioned to stage 2
* Sierra oncology inc - sra737 development program remains on track Source text for Eikon: Further company coverage: