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

Summary

Objectives

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 166 subjects with
active cGVHD will be randomized (1:1) to receive treatment with one of two belumosudil
(formerly known as KD025) regimens:

- Arm A: belumosudil 200 mg QD

- Arm B: belumosudil 200 mg BID

With Amendment 2, the sample size was increased from approximately 126 subjects, with
additional subjects to be enrolled as follows:

- 20 adolescents

- 20 adults into a site-specific Companion Study to collect biospecimens

These additional subjects will also be randomized (1:1) to Arm A or Arm B.

Any adolescent taking a proton pump inhibitor (PPI) or a strong CYP3A4 inducer will begin
Cycle 1 Day 1 at the escalated dose of belumosudil 200 mg 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 clinically significant progression of cGVHD. Subjects who have not achieved a
response after 12 cycles of belumosudil should be withdrawn if in the Investigator's judgment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 (Appendix A). 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.