Efficacy and Safety of KD025 in Subjects With cGVHD After At Least 2 Prior Lines of Systemic Therapy

Phase 2, open label, randomized, multicenter study in subjects with cGVHD who have previously
been treated with at least 2 prior lines of systemic therapy. Approximately 126 subjects with
active cGVHD will be randomized (1:1) to receive treatment with one of two KD025 regimens:

- Arm A: KD025 200mg QD

- Arm B: KD025 200mg BID

Randomization will be stratified according to prior cGVHD treatment with ibrutinib (Yes / No)
and severe cGVHD at baseline (Yes / No). Subjects may receive treatment in 28-day treatment
cycles until progression of cGVHD. Subjects who have not achieved a response after 12 cycles
of KD025 should be withdrawn if in the Investigator's judgment there is no evidence of
clinical benefit. Subjects will undergo evaluations as outlined in the Study Assessments
table. The primary endpoint is the overall response rate (ORR) with responses as defined by
the 2014 National Institute of Health (NIH) Consensus Development Project on clinical trials
in cGVHD.

Inclusion Criteria:

1. Adult male and female subjects at least 18 years of age who have had allogenic
hematopoietic cell transplant (HCT).

2. Previously received at least 2 and not more than 5 lines of systemic therapy for cGVHD

3. Receiving glucocorticoid therapy with a stable dose over the 2 weeks prior to
screening

4. Have persistent cGVHD manifestations and systemic therapy is indicated

5. Karnofsky Performance Score of ≥ 60

Exclusion Criteria:

1. Received a systemic investigational cGVHD treatment within 28 days of study entry.
Prior treatment is allowed with a washout of at least 5 half-lives or 28 days. (Note:
Corticosteroids, calcineurin inhibitors, sirolimus, MMF, methotrexate and ECP are
acceptable and subjects must have been on a stable dose / regimen of these for at
least 2 weeks prior to screening).

2. Histological relapse of the underlying cancer or post-transplant lymphoproliferative
disease at the time of screening.

3. Current treatment with ibrutinib. Prior treatment with ibrutinib is allowed with a
washout of at least 28 days prior to randomization.