ALBERT

Description: Introduction: cGVHD remains a leading cause of post-transplant morbidity / mortality, exhibiting features of both autoimmune and fibrotic diseases across multiple organ systems. cGVHD is characterized by an imbalance between effector and regulatory arms of the immune system that results in over production of inflammatory cytokines including IL-17 and IL-21. Moreover, a persistent reduction in the number of regulatory T (Treg) cells limits the ability of the immune system to re-calibrate this pro-inflammatory environment. KD025 is an orally available Rho-associated coiled-coil kinase 2 (ROCK2) selective inhibitor. In vitro data have demonstrated that KD025 (1) attenuates IL-21 and IL-17 secretion in human CD4+ T cells via STAT3, IRF4 and RORγt regulation, and (2) leads to increased percentages of Foxp3+ CD4+ T cells via a STAT5-dependent mechanism and upregulates the suppressive function of human Tregs. These MOA suggest that KD025 modulates immune homeostasis by shifting the Th17/Treg balance towards a Treg phenotype. No studies have examined KD025 effects in patients with dysregulation associated with high Th17 and low Tregs. Methods: KD025-208 enrolled 3 cohorts (C1: 200 mg QD, C2: 200 mg BID, and C3: 400 mg QD) of patients (pts) with cGVHD after 1-3 prior lines of systemic therapy. Treatment is in 28-Day cycles until disease progression or unacceptable toxicity. The primary endpoint is the overall response rate (ORR) (% pts achieving partial response (PR) or complete response (CR)) as per 2014 NIH response criteria. Secondary endpoints include duration of response (DOR) and corticosteroid (CS) dose reductions. Exploratory endpoints include Lee Symptom Scale (LSS) score and pharmacodynamics (PD). Peripheral blood samples were collected from all pts at Cycle 1 Day 1 (C1D1), C2D1, C4D1 and C6D25, and shipped at ambient temperature. PBMC were isolated and kept frozen until analysis. The intracellular expression of IL-17A and FOXP3 on viable CD3+ CD4+ cells was determined by using multicolor flow cytometry. Results: Data as of 6-June-2018 for C1 and C2 are included; C3 data will be available 4Q18. 17 and 16 pts were enrolled in C1 and C2 with median age 52 years, median time from cGVHD diagnosis to KD025 treatment of 19 months, and a median of 3 prior treatment regimens. Median duration of treatment was 37 (C1) and 33 (C2) weeks (wks). KD025 demonstrated an ORR of 65% in C1 and 63% in C2. ORR in key subgroups is shown below. Responses were rapid (76% achieved at first assessment at 8 wks) and durable with 82% (C1) and 50% (C2) of responders sustaining response for ≥20 wks. Responses including CRs were observed across all affected organ systems except lung (mouth, eyes, joints/ fascia, skin, upper GI, lower GI, esophagus, liver). A previously reported lung PR was deemed on review to be IPF with no cGVHD involvement. During treatment with KD025, median CS dose was reduced by 44% (C1) and 26% (C2). 76% and 56% of pts achieved CS dose reductions. 5/33 (15%) pts discontinued CS. 65% (C1) and 50% (C2) achieved a meaningful improvement (≥7 point reduction) in the LSS score, including both responders (67%) and non-responders (42%). KD025 has been well tolerated. AEs reported were generally consistent with those expected in pts with advanced cGVHD treated with CS. Common AEs were increased LFTs (42%), URI (33%), anemia (27%), nausea (24%), diarrhea (24%) and fatigue (21%). Increased LFTs did not lead to treatment discontinuation, commonly occurred prior to KD025 dosing and were often considered attributable to cGVHD. Grade 3+ LFT increases were reported for 6 (18%) pts. 2 pts discontinued treatment due to AEs possibly related to KD025 (headache, diarrhea). SAEs were reported for 11/33 (33%) pts, none considered related to KD025 treatment. There was no apparent increased risk of infection. Exploratory PD analyses of PBMCs across C1 and C2 revealed an early increase in the percentage of CD4+ Treg cells by C2D1 of KD025 treatment with a simultaneous decrease in Th17 cells. The percentage of CD4+ Tregs continued to increase, and the Th17 cells continued to decrease through C4D1 and C6D25. Conclusion: Treatment with KD025 has demonstrated encouraging clinical responses in cGVHD pts with little toxicity. Responses have been clinically meaningful as evidenced by durability, reductions in CS doses and improvement in LSS score. Exploratory PD data indicate treatment with KD025 may modulate immune homeostasis by restoring the Th17/Treg balance. Figure. Figure. Disclosures Jagasia: Incyte Corporation: Membership on an entity's Board of Directors or advisory committees. Salhotra:Kadmon Corporation, LLC: Consultancy. Bachier:Sanofi: Speakers Bureau; Seattle Genetics: Speakers Bureau. Weisdorf:Seattle Genetics: Consultancy; Pharmacyclics: Consultancy; Equillium: Consultancy; SL Behring: Consultancy; FATE: Consultancy. Green:Kadmon Corporation, LLC: Employment. Schueller:Kadmon Corporation, LLC: Employment. Zanin-Zhorov:Kadmon Corporation, LLC: Employment. Weiss:Kadmon Corporation, LLC: Employment. Eiznhamer:Kadmon Corporation, LLC: Employment. Aggarwal:Kadmon Corporation, LLC: Employment. Blazar:Kadmon Corporation, LLC: Consultancy, Research Funding. Lee:Takeda: Research Funding; Kadmon: Research Funding; Amgen: Consultancy, Research Funding; Mallinckrodt: Honoraria; Incyte: Consultancy; Pfizer: Consultancy; Onyx: Research Funding.

Description: Introduction: cGVHD exhibits both autoimmune and fibrotic features across multiple organ systems. KD025 is an orally available Rho-associated coiled-coil kinase 2 (ROCK2) selective inhibitor that (1) decreases human T cell IL-21 and IL-17 secretion via STAT3, IRF4 and RORγt regulation; (2) increases percentages and function of Foxp3+ T regulatory cells via a STAT5-dependent mechanism; and (3) reverses established cGVHD in 2 distinct preclinical models. KD025 modulates the immune system by shifting the Th17/Treg balance towards homeostasis. Methods: KD025-208 enrolled 3 sequential cohorts (C) (C1: 200 mg QD, C2: 200 mg BID and C3: 400 mg QD) of patients (pts) with cGVHD after 1-3 prior lines of systemic therapy. Treatment is in 28-Day continuous cycles until disease progression or unacceptable toxicity. The primary endpoint is the overall response rate (ORR) as per 2014 NIH response criteria in the mITT population. Additional endpoints include duration of response (DOR), corticosteroid (CS) dose reductions, failure free survival (FFS) and Lee Symptom Scale (LSS) score. Results: 17, 16 and 21 pts were enrolled in C1, C2, and C3 between Sep-2016 and Mar-2018. Data as of 8-Mar-2019 are included, reflecting a median duration of follow up of 112, 97 and 64 weeks (wks), respectively. At enrollment, median age was 52 yrs, median time from cGVHD diagnosis to treatment was 20 mos, and patients had received a median of 2 prior lines of therapy. 71% of patients were refractory to the last line of therapy prior to enrollment. 50% of pts had cGVHD in ≥4 organs. The median duration of treatment was 37, 33 and 39 wks, respectively. As of 30-Jun-2019, 24% of pts had received 〉18 months of KD025 therapy. 14 pts remain on KD025 treatment. Reasons for discontinuation included cGVHD progression (18), pt voluntary withdrawal (7), relapse of underlying disease (5), investigator decision (5), AE (3) and death (2). ORR (95% CI) was 65% (38%, 85%) in C1, 69% (41%, 89%) in C2, and 62% (38%, 82%) in C3, i.e. 65% (51%, 77%) across all 3 cohorts. Responses were achieved across key subgroups with ORRs of 62% (24/39) in pts with ≥2 prior lines of systemic therapy, 70% (19/27) in pts with ≥4 organs involved and 60% (25/42) in pts with severe cGVHD. CRs were observed in all affected organs except lung; PRs were observed in lung. Responses were rapid, and often achieved within 8 wks, although 4/35 responses occurred after 24 wks. Of note, organs with fibrotic manifestations such as lungs, joints and eyes responded after 24 weeks in some pts. Responses were durable, with a Kaplan-Meier (K-M) median DOR of 34 weeks across all cohorts. 57% of responders sustained a response for ≥20 wks. The K-M median DOR was 34 wks in pts with ≥2 prior lines of systemic therapy. FFS at 6, 12, 18 and 24 mos was 76%, 47%, 40% and 33%, respectively. Baseline median CS dose was 0.21 mg/kg/day of prednisone equivalent. During treatment with KD025, the median CS dose was reduced by 50%. 67% of pts reduced CS dose and 20% discontinued CS completely. The median CS dose reduction was 66% in responders and 25% in non-responders. 52% of pts reported a clinically meaningful improvement (≥7-point reduction) in LSS score during treatment with KD025 with a median time to improvement of 9 wks and a duration for responders of 21 wks. 63% of responders and 32% of non-responders reported a meaningful improvement in LSS score. KD025 was well tolerated with a median Relative Dose Intensity of 98%. Dose reductions/interruptions occurred in 21/54 pts; median duration of interruption was 8.5 days (range 3-20). AEs were consistent with those expected in cGVHD pts receiving CS. Common AEs were URI (35%), diarrhea (31%), nausea (31%), fatigue (30%), dyspnea (28%), increased LFTs (24%), and peripheral edema (22%). 63% had a Grade ≥3 AE; the most common was dyspnea (13%).