Cambridge Brain Mets Trial 1: A Proof-of-principle Phase 1b/Randomised Phase 2 Study of Afatinib Penetration Into Cerebral Metastases for Patients Undergoing Neurosurgical Resection, Both With and Without Prior Low-dose, Targeted Radiotherapy

Brain metastases occur in 20-40% of all patients with cancer, with an incidence 10 times higher than that of primary malignant brain tumours. patients with brain metastases are an underserved population. Overall they have a poor prognosis with a median survival of 1-2 months with corticosteroids and only 5-7 months after whole brain radiotherapy. An important factor in the poor prognosis of patients with brain metastases is the inability of many drugs to penetrate the blood-brain-barrier into tumour tissue.Combination therapy with surgical excision, radiotherapy and novel drugs could potentially improve the prognosis for some patients.

CamBMT1 is an open label, 3 Arm randomised Phase 2 trial investigating whether administration of a low dose of targeted radiotherapy during afatinib treatment could increase the concentration of drug penetration into brain metastases.

Eligible patients in Phase 2 will be randomised to 1 of 3 Arms:

Arm 1: no radiotherapy Arm 2: 2Gy radiotherapy Arm 3: 4Gy radiotherapy All patients will also receive 11 days of afatinib treatment at the recommended Phase 2 dose, previously determined in a Phase 1b safety run-in phase.

On Day 10, of afatinib treatment patients randomised to Arms 2 or 3 will receive their allocated dose of radiotherapy On Day 12, patients will undergo neurosurgical resection of their brain metastasis/ses.