EORTC 1635-BTG: IDH mutated 1p/19q intact lower grade glioma following resection: Wait Or Treat? IWOT - A phase III study
Indication :

Gliome de bas grade avec mutation IDH sans codélétion 1p/19q

Sponsor :


Phase :


Ligne :


Traitement :

radiothérapie cérébrale (RC) suivie de 12 cycles de témozolomide (TMZ) vs surveillance active

Site :


Contact(s) :
Andreas Hottinger
Investigateur Principale

Département d'oncologie

Rue du Bugnon 46

079 556 52 71

Primary objective :

To determine whether in patients with oligosymptomatic IDHmt diffuse and anaplastic astrocytoma
immediate post-surgery RT followed by 12 cycles TMZ improves the next intervention free survival (NIFS)
compared to a post-operative active surveillance period followed by a first treatment (preferably radioand/
or chemotherapy).

Inclusion criteria :

•Histologically WHO grade II (diffuse) or III (anaplastic) astrocytoma, IDHmt without 1p/19q codeletion
(local diagnosis) (Ref. 1)
• Time since diagnostic surgery or first resection ≤ 6 months
• No need for immediate radiotherapy followed by chemotherapy
• Functional deficits due to the resection is allowed
• Patients for whom by local judgment an active surveillance policy is a realistic management
• Adults ≥ 18years of age
• WHO PS 0-2
• Adequate hematological, renal, and hepatic function
• Presence of at least one paraffin block from the initial diagnosis for pathology review and
translational research. If a representative FFPE block is not available, the collection of optimally 36,
minimally 24 x 5 μm, unstained slides is required.
• At the time of randomization presence only of a non-enhancing tumor on T1 weighted contrast
enhanced MR images; some faint non-nodular enhancement or enhancement that can be ascribed to
the surgical resection or peri-operative ischemia is allowed. Preoperative enhancement is allowed
provided this area is resected as shown on postoperative imaging

Exclusion criteria :

• Presence of signs of increased intracranial pressure after surgery
• Requirement of steroids for control of tumor symptoms
• Presence of uncontrolled seizures after surgery
• Functional deficits due to the tumor
• Presence of contra-indications for radiotherapy
• Hypersensitivity to dacarbazine (DTIC), to the active substance or to any of the excipients used for
TMZ capsules
• Prior chemotherapy, or prior radiotherapy to the brain
• Pregnancy or breastfeeding
• Known HIV, chronic hepatitis B, or hepatitis C infection
• Inability to take oral medication (e.g., frequent vomiting, partial bowel obstruction)
• Concurrent severe or uncontrolled medical disease (e.g., active systemic infection, diabetes,
hypertension, coronary artery disease, psychiatric disorder) that, in the opinion of the investigator,
would compromise the safety of the patient or compromise the ability of the patient to complete the
• Prior or second invasive malignancy, except non-melanoma skin cancer, completely resected cervical
or prostate cancer