PATIENT-DERIVED INTESTINAL ORGANOIDS PREDICT DRUG RESPONSIVENESS OF TOFACITINIB, A PAN JAK-STAT INHIBITOR.

Background:
The pathogenesis of inflammatory bowel disease (IBD) involves crosstalk between genetic and microbial factors that influence immune reactions. Tofacitinib, a pan JAK-STAT inhibitor, is a small molecule indicated for the treatment of moderate-to-severe ulcerative colitis (UC). However, approximately 30-40% of patients will not response to tofacitinib, and underscores the importance of identifying individuals who may respond to drug prior to therapy initiation. We utilized patient-derived intestinal organoids to predict responsiveness to tofacitinib.

Methods:
We cultured colonic organoids derived from endoscopic mucosal pinch biopsies from 4 healthy donors (HD) and 24 patients with UC initiating tofacitinib at weeks 0 and 24. Mechanically disrupted organoids were dissociated into 96-well tissue culture plate. The organoids were cultured in differentiation media (IF media) supplemented with Y-27632 for the first 2 days, and then stimulated with 20 ng/ml of human(h) TNFα and 1,000 IU/ml of hIFNβ or 20 ng/ml of hTNFα and hIFNγ in the presence of DMSO, 1, or 10 μM of tofacitinib for 5 days. Percent viable organoids was determined by daily quantification of the number of intact organoids. Change in total Mayo scores at weeks 0 and 24 were correlated with organoid viability.

Results:
Tofacitinib at 1 and 10 μM significantly rescued the decreased viability of organoids-derived from both HD and UC patients under hTNFα+hIFNβ or hTNFα+hIFNγ stimulation, consistent with tofacitinib sensitivity (Figure 1A). UC patient-derived organoids showed heterogenous viability when treated with 1 μM tofacitinib (Figure 1A). 10 UC organoid lines were sensitive to tofacitinib (UC-S) and phenocopied HD-derived organoids. 14 UC organoid lines displayed comparable viability under hTNFα+hIFNγ stimulation despite 1μM of tofacitinib, consistent with tofacitinib tolerance (UC-T1 and 2; Figure 1B). 7 organoid lines (UC-T2) demonstrated impaired viability rescue under both cytokine combinations with tofacitinib (Figure 1B). Total Mayo scores of patients corresponding to UC-S were significantly decreased after tofacitinib treatment (Figure 1C). Total Mayo scores were unchanged in the patients corresponding to UC-T1 and T2 (Figure 1C).

Conclusion:
Our findings indicate that patient-derived intestinal organoids display heterogeneous sensitivity to tofacitinib. The ability of tofacitinib to rescue organoid viability directly correlated with change in the total Mayo score, suggesting that organoids are a useful platform to predict drug responsiveness of individual patients.