Exposure-response analyses of pemigatinib in patients with myeloid/lymphoid neoplasms with fibroblast growth factor receptor 1 rearrangement.

Pemigatinib is a selective, potent, orally administered inhibitor of fibroblast growth factor receptor (FGFR)1-3 with antitumor activity in multiple solid tumors. Pemigatinib is used to treat adults with previously treated metastatic or surgically unresectable cholangiocarcinoma with FGFR2 alterations, as well as adults with relapsed or refractory myeloid/lymphoid neoplasm (MLN) with an FGFR1 rearrangement (MLN-FGFR1). Data from recent clinical studies were used to develop pemigatinib exposure-response models for patients with MLN-FGFR1 and to evaluate the impact of pemigatinib exposure on efficacy and safety. The degree of pemigatinib exposure did not predict the level of efficacy in patients with MLN-FGFR1 in this analysis. Pemigatinib exposure was a significant predictor of the frequency of clinically relevant treatment-emergent adverse events. The estimated probabilities of developing hyperphosphatemia, dry mouth, nail toxicity, alopecia, stomatitis, and diarrhea were higher with a continuous dosing schedule versus an intermittent dosing schedule.