Inclusion Criteria:

- Undergone allogeneic hematopoietic stem cell transplant (HSCT)

- Clinically diagnosed with acute GvHD requiring systemic therapy with corticosteroids.

- HR-aGvHD must meet one of the following clinical features within 72 hours prior to
randomization: (a) high-risk as per Refined Minnesota Criteria; OR (b) One of the
following: (i) isolated stage 2 involvement of the lower GI tract; (ii) Stage 1 lower
GI tract disease with skin involvement

- Evidence of myeloid engraftment post allogeneic HSCT

- Life expectancy of at least one month

Exclusion Criteria:

- Received any systemic treatment for aGvHD other than corticosteroids +/- calcineurin
inhibitors

- Chronic GvHD or overlap syndrome with both acute and chronic features of GvHD

- Relapsed primary malignancy since

- received more than one allogeneic HSCT

- Clinically significant respiratory, renal or cardiac disease

- Cholestatic disorders or sinusoidal obstructive syndrome/veno-occlusive disease of the
liver

- Any active uncontrolled infection requiring treatment and likely to impact on the
ability of the subject to participate in the trial.

- Known infection with CMV, EBV, HHV-6, HBV, HCV, HIV or Tuberculosis. If the treatment
for CMV, EBV, HHV-6, HBV, HCV has commenced the subject is eligible.

- Known sensitivity to dimethylsulfoxide (DMSO) or any other component of CYP-001.

- Received any investigational treatment agent within 30 days or within 5 half-lives of
Screening, whichever is greater.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 2/27/23. Questions regarding updates should be directed to the study team contact.