A Study to Evaluate the Efficacy and Safety of Pemigatinib (INCB054828) in Subjects With Myeloid/Lymphoid Neoplasms With FGFR1 Rearrangement - (FIGHT-203)

Inclusion Criteria:

* Documented lymphoid or myeloid neoplasm with 8p11 rearrangement known to lead to FGFR1 activation, based on standard diagnostic cytogenetic evaluation performed locally, before signing informed consent for this study.
* Eligible subjects must:

  * Have relapsed after stem cell transplantation or after other disease modifying therapy, OR
  * Not be current candidates for stem cell transplantation or other disease modifying therapies.
* Note: All relapsed/refractory subjects must have evidence of either cytogenetic or hematological disease and have no evidence of residual toxicity (eg, graft-versus-host disease requiring treatment).
* Life expectancy ≥ 12 weeks.
* Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2.

Exclusion Criteria:

* Prior receipt of a selective FGFR inhibitor.
* History and/or current evidence of ectopic mineralization/calcification, including but not limited to soft tissue, kidneys, intestine, myocardia, or lung, except calcified lymph nodes and asymptomatic arterial or cartilage/tendon calcifications.
* Current evidence of corneal disorder/keratopathy, including but not limited to bullous/band keratopathy, corneal abrasion, inflammation/ulceration, and keratoconjunctivitis, as confirmed by ophthalmologic examination.
* Use of any potent cytochrome P450 3A4 inhibitors or inducers within 14 days or 5 half-lives (whichever is shorter) before the first dose of study drug.