Inclusion Criteria:

• At least 18 years of age at the time of signing informed consent.
• Pathologically diagnosed conventional chondrosarcoma. Patients must have tumor sample(s) available or provide tumor samples from a new biopsy
• Metastasis to at least 1 location or locally advanced disease that is deemed unresectable by a surgeon
• At least 1 radiologically measurable target lesion per RECIST 1.1.
• Patients must have documented radiographic progression of disease within the 6-month period prior to screening. (MRI or CT Scan)
• Eastern Cooperative Oncology Group (ECOG) performance status: 0 or 1.
• Life expectancy of at least 3 months
• All women of child-bearing potential (WCBP), all sexually active male patients, and all partners of patients must agree to use adequate methods of birth control throughout the study and for 30 days after the last dose of study drug.
• Ability to adhere to the study visit schedule and all protocol requirements.
• Voluntarily signed an informed consent form.

Exclusion Criteria:

• Other invasive malignancies diagnosed within the last 5 years, except non-melanoma skin cancer and localized cured prostate and cervical cancer.
• Systemic anti-cancer therapy within 21 days prior to the first dose of study drug, or radiotherapy within 14 days prior to the first dose of study drug.
• Prior treatment with a Hedgehog pathway inhibitor
• Medically significant surgical procedures or significant traumatic injury within 28 days before Day 1.
• Inadequate hematologic function defined by:
• Hemoglobin <8.0 g/dL (80 g/L) (may be increased to this level with transfusion as long as there is no evidence of active bleeding).
• Inadequate hepatic function defined by:
• Aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) >2.5 x upper limit of normal (ULN).
• Total bilirubin >1.5 x ULN (with the exception of patients with Gilbert's disease).
• Cirrhotic liver disease, ongoing alcohol abuse, or known chronic active or acute hepatitis.
• Inadequate renal function defined by serum creatinine >1.5 x ULN
• Patients with a history of stroke, unstable angina, myocardial infarction, or ventricular arrhythmia requiring medication or mechanical control within the last 6 months.
• Presence of active infection or systemic use of antibiotics within 72 hours of treatment.
• Significant co-morbid condition or disease, which in the judgment of the Investigator, would place the patient at undue risk or interfere with the study. Examples include, but are not limited to sepsis and recent significant traumatic injury.
• Known human immunodeficiency virus (HIV) positivity.
• Known hypersensitivity to IPI-926, or any of the excipients in IPI-926 or placebo capsules.
• Pregnant or lactating women.
• Current administration of the medications or foods which are known to be moderate or strong inhibitors of CYP3A4 activity