Duration of response was defined as the time from the first assessment of confirmed CR or PR until progressive disease (PD) (according to RANO and assessed by an independent centralized radiological review committee) or death (whichever occurred first). Progression was defined by any of the following: ≥25% increase in the sum of the products of perpendicular diameters of enhancing lesions (compared with baseline if no decrease) on stable or increasing doses of corticosteroids; a significant increase in T2/FLAIR nonenhancing lesions on stable or increasing doses of corticosteroids compared with baseline scan or best response after initiation of therapy, not due to comorbid events; the appearance of any new lesions; clear progression of nonmeasurable lesions; or definite clinical deterioration not attributable to other causes apart from the tumor, or to decrease in corticosteroid dose.

Duration of response was defined as the time from the first assessment of unconfirmed CR or PR until progressive disease (PD) (according to RANO and assessed by an independent centralized radiological review committee) or death (whichever occurred first). Progression was defined by any of the following: ≥25% increase in the sum of the products of perpendicular diameters of enhancing lesions (compared with baseline if no decrease) on stable or increasing doses of corticosteroids; a significant increase in T2/FLAIR nonenhancing lesions on stable or increasing doses of corticosteroids compared with baseline scan or best response after initiation of therapy, not due to comorbid events; the appearance of any new lesions; clear progression of nonmeasurable lesions; or definite clinical deterioration not attributable to other causes apart from the tumor, or to decrease in corticosteroid dose.

ORR was defined as the percentage of participants who achieved an unconfirmed best overall response of CR or PR based on RANO as determined by investigator assessment. CR requires all of the following: disappearance of all enhancing measurable/nonmeasurable disease sustained for ≥4 weeks; no new lesions; stable/improved nonenhancing lesions; off corticosteroids/on physiologic replacement doses only and stable/improved clinically. PR requires all of the following: ≥50% decrease, compared with baseline, in the sum of products of perpendicular diameters of all measurable enhancing lesions sustained for ≥4 weeks; no progression of nonmeasurable disease; no new lesions; stable or improved nonenhancing lesions on same/lower dose of corticosteroids compared with baseline scan; on a corticosteroid dose not greater than the dose at time of baseline scan and stable/improved clinically.

An adverse event (AE) was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not it was considered drug related. An AE could therefore have been any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drug. A TEAE was defined as an AE reported for the first time or the worsening of a pre-existing event after the first dose of pemigatinib and within 30 days of the last dose of pemigatinib.

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not it was considered drug related. A TEAE was defined as an AE reported for the first time or the worsening of a pre-existing event after the first dose of pemigatinib and within 30 days of the last dose of pemigatinib. The severity of AEs was assessed using Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 Grades 1 through 5. Grade 1: mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; treatment not indicated. Grade 2: moderate; minimal, local, or noninvasive treatment indicated; limiting age-appropriate activities of daily living. Grade 3: severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living. Grade 4: life-threatening consequences; urgent treatment indicated. Grade 5: fatal.

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not it was considered drug related. An AE could therefore have been any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drug. A TEAE was defined as an AE reported for the first time or the worsening of a pre-existing event after the first dose of pemigatinib and within 30 days of the last dose of pemigatinib.

DCR was defined as the percentage of participants who achieved a best overall response of CR, PR, or stable disease (SD) based on RANO as determined by an independent centralized radiological review committee. In the case of SD, measurements must have met the SD criteria after the date of the first dose at a minimum interval of 42 days. SD occurred if the participant didn't qualify for CR, PR, or PD and required the following: stable nonenhancing (T2/FLAIR) lesions on same or lower dose of corticosteroids compared with baseline scan and clinically stable status.

PFS was defined as the time from the first dose until progressive disease (according to RANO and assessed by an independent centralized radiological review committee) or death (whichever occurred first). Progression was defined by any of the following: ≥25% increase in the sum of the products of perpendicular diameters of enhancing lesions (compared with baseline if no decrease) on stable or increasing doses of corticosteroids; a significant increase in T2/FLAIR nonenhancing lesions on stable or increasing doses of corticosteroids compared with baseline scan or best response after initiation of therapy, not due to comorbid events; the appearance of any new lesions; clear progression of nonmeasurable lesions; or definite clinical deterioration not attributable to other causes apart from the tumor, or to decrease in corticosteroid dose.

Overall survival was defined as the time from the first dose of study drug to death due to any cause.

Participants with recurrent non-glioblastoma central nervous system (CNS) tumors with defined activating FGFR gene alterations received pemigatinib 13.5 milligrams (mg) once daily (QD) on a 2-week on-therapy and 1-week off-therapy schedule as long as they were receiving benefit and had not met any criteria for treatment discontinuation. Defined activating gene alterations included FGFR 1-3 fusions or rearrangements with intact FGFR kinase domain, or a defined set of FGFR 1-3 activating mutations or in-frame deletions.

Participants with recurrent non-glioblastoma central nervous system (CNS) tumors with defined activating FGFR gene alterations received pemigatinib 13.5 milligrams (mg) once daily (QD) on a 2-week on-therapy and 1-week off-therapy schedule as long as they were receiving benefit and had not met any criteria for treatment discontinuation. Defined activating gene alterations included FGFR 1-3 fusions or rearrangements with intact FGFR kinase domain, or a defined set of FGFR 1-3 activating mutations or in-frame deletions.

Participants with recurrent non-glioblastoma central nervous system (CNS) tumors with defined activating FGFR gene alterations received pemigatinib 13.5 milligrams (mg) once daily (QD) on a 2-week on-therapy and 1-week off-therapy schedule as long as they were receiving benefit and had not met any criteria for treatment discontinuation. Defined activating gene alterations included FGFR 1-3 fusions or rearrangements with intact FGFR kinase domain, or a defined set of FGFR 1-3 activating mutations or in-frame deletions.

Participants with recurrent non-glioblastoma central nervous system (CNS) tumors with defined activating FGFR gene alterations received pemigatinib 13.5 milligrams (mg) once daily (QD) on a 2-week on-therapy and 1-week off-therapy schedule as long as they were receiving benefit and had not met any criteria for treatment discontinuation. Defined activating gene alterations included FGFR 1-3 fusions or rearrangements with intact FGFR kinase domain, or a defined set of FGFR 1-3 activating mutations or in-frame deletions.

Participants with recurrent non-glioblastoma central nervous system (CNS) tumors with defined activating FGFR gene alterations received pemigatinib 13.5 milligrams (mg) once daily (QD) on a 2-week on-therapy and 1-week off-therapy schedule as long as they were receiving benefit and had not met any criteria for treatment discontinuation. Defined activating gene alterations included FGFR 1-3 fusions or rearrangements with intact FGFR kinase domain, or a defined set of FGFR 1-3 activating mutations or in-frame deletions.

Participants with recurrent non-glioblastoma central nervous system (CNS) tumors with defined activating FGFR gene alterations received pemigatinib 13.5 milligrams (mg) once daily (QD) on a 2-week on-therapy and 1-week off-therapy schedule as long as they were receiving benefit and had not met any criteria for treatment discontinuation. Defined activating gene alterations included FGFR 1-3 fusions or rearrangements with intact FGFR kinase domain, or a defined set of FGFR 1-3 activating mutations or in-frame deletions.