Ivosidenib in Participants With Locally Advanced or Metastatic Conventional Chondrosarcoma Untreated or Previously Treated With 1 Systemic Treatment Regimen

Inclusion Criteria:

• Have a histopathological diagnosis (fresh or banked tumor biopsy sample collectedwithin the last 3 years) consistent with locally advanced or metastatic conventionalchondrosarcoma Grades 1, 2, or 3 and not eligible for curative resection.

• Have at least one BICR-confirmed measurable lesion as defined by RECIST v1.1.Participants who have received prior radiation therapy are eligible providedmeasurable disease falls outside of the treatment field or within the field and hasshown ≥20% growth in size since post-treatment assessment.

• Have received 0 or 1 prior systemic treatment regimen in the advanced/metastaticsetting for chondrosarcoma.

• Have radiographic progression/recurrence of disease according to RECIST v1.1 definedas:

1. Radiographic progression of disease (local and/or distant) documented by 2imaging assessments performed no more than 6 months (±2 weeks) apart within 12months before randomization.OR

2. Any recurrence of disease (local and/or distant) after complete surgicalresection and documented by imaging within 6 months (±2 weeks) beforerandomization.

• Have documented IDH1 gene-mutated disease (from a fresh tumor biopsy or the mostrecent banked tumor tissue available that was sourced from either a primary ormetastatic tumor lesion) based on central laboratory testing (R132C/L/G/H/S mutationvariants tested)

• Have recovered from any clinically relevant sequelae and toxic effects of any priorsurgery, radiotherapy, or other therapy intended for the treatment of cancer.

Exclusion Criteria:

• Are unable to swallow oral medication.

• Pregnant or lactating women.

• Are participating in another interventional study at the same time; participation innoninterventional registries or epidemiological studies is allowed.

• Have received prior therapy with an IDH1 inhibitor

• Have received systemic anticancer therapy <2 weeks prior to randomization (forinvestigational or immune-based anticancer therapy <4 weeks).

• Have received radiotherapy <2 weeks prior to randomization.

• Have known symptomatic brain metastases requiring steroids >10 mg per day prednisone (or equivalent). Participants with previously diagnosed brain metastases areeligible if they have completed their treatment and have recovered from the acuteeffects of radiation therapy or surgery prior to randomization, have discontinued orreduced corticosteroid treatment <=10 mg per day for these metastases for at least 4weeks and have radiographically stable disease of brain lesions for at least 3months prior to randomization.

• Have a history of another primary cancer, with the exception of: a) curativelyresected non-melanoma skin cancer; b) curatively treated carcinoma in situ; or c)pT1-2 prostatic cancer Gleason score <6 or d) participant is free of other primarysolid or liquid tumor for ≥ 1 year prior to the start of study treatment and, in theopinion of the Investigator, the disease will not affect participant's outcome inthe setting of current chondrosarcoma diagnosis.

• Have had major surgery within 4 weeks prior to randomization.

• Have significant active cardiac disease within 6 months prior to randomization,including New York Heart Association (NYHA) Class III or IV congestive heartfailure; myocardial infarction; unstable angina; and/or stroke.

• Have LVEF <40% by ECHO scan (or by other methods according to institutionalpractice) obtained within 28 days prior to randomization.

• Have a heart-rate corrected QT interval (using Fridericia's formula) (QTcF) ≥ 450msec or other factors that increase the risk of QT prolongation or arrhythmic events (eg, heart failure, hypokalemia, family history of long QT interval syndrome).Participants with a bundle branch block combined with a prolonged QTcF interval maybe permitted based on local cardiology assessment.

• Have known medical history of progressive multifocal leukoencephalopathy (PML).