⁃ A. Confirmed diagnosis of a ROS1 gene fusion-positive malignancy, other than NSCLC, that has been identified using an analytically validated sequencing technique.

⁃ B. Patients must be able and willing to undergo a fresh tissue biopsy.

⁃ C. Patients with a BSA of 0.43m\^2 and over.

⁃ D. ADULT PATIENTS (≥18 years): Adequate organ function as per haematological and biochemical indices within the ranges shown below. These measurements should be performed to confirm the patient's eligibility.

⁃ Haemoglobin (Hb): ≥90 g/L (transfusion allowed)

⁃ Absolute neutrophil count (ANC): ≥1.5 × 10\^9/L (no granulocyte colony-stimulating factor \[GCSF\] support in preceding 72 hours)

⁃ Platelet count: ≥100 × 10\^9/L (unsupported for 72 hours)

⁃ Bilirubin: \<2.5 × upper limit of normal (ULN). Patients with known Gilbert's syndrome who have a serum bilirubin: ≤3 × ULN may be enrolled.

⁃ Alanine aminotransferase (ALT) and aspartate aminotransferase (AST): ≤2.5 × ULN or ≤5 × ULN if raised due to metastases.

⁃ estimated glomerular filtration rate (eGFR): ≥30 mL/min (uncorrected value)

⁃ Coagulation - prothrombin (PT) (or international normalized ratio \[INR\]), and activated partial thromboplastin clotting time (aPTT): ≤1.5 × limit of normal (unless patient is on anticoagulants e.g. warfarin \[INR should be stable and within indicated therapeutic range\], or direct oral anticoagulants \[DOAC\]).

⁃ E. PAEDIATRIC PATIENTS (\<18 years): Adequate organ function as per haematological and biochemical indices within the ranges shown below. These measurements should be performed to confirm the patient's eligibility.

⁃ Hb: ≥80 g/L (transfusion allowed)

⁃ ANC: ≥1.0 × 10\^9/L (no GCSF support in preceding 72 hours)

⁃ Platelet count: ≥75 × 10\^9/L (unsupported for 72 hours)

⁃ Bilirubin: ≤1.5 × ULN for age

⁃ ALT and AST: ≤2.5 × ULN for age or \<5 × ULN if raised due to metastases.

⁃ eGFR: \>70 ml/min/1.73 m\^2

⁃ INR or PT and aPTT: ≤1.5 x ULN for age (unless patient is on anticoagulants e.g. warfarin \[INR should be stable and within indicated therapeutic range\], or DOAC).

⁃ F. Women of childbearing potential are eligible provided that they meet the following criteria:

• Have a negative serum or urine pregnancy test before enrolment and either:

• Agree to use one form of highly effective birth control method such as:

⁃ I. Oral, intravaginal or transdermal combined (oestrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation.

⁃ II. Oral, injectable or implantable progestogen-only hormonal contraception associated with inhibition of ovulation

⁃ III. Intrauterine device (IUD)

⁃ IV. Intrauterine hormone-releasing system (IUS)

⁃ V. Bilateral tubal occlusion

⁃ VI. Vasectomised partner

⁃ Plus a barrier method if using a hormonal method: male or female condom with or without spermicide; cap, diaphragm or sponge with spermicide.

⁃ OR

⁃ • Sexual abstinence;

⁃ Effective from the first administration of entrectinib, throughout the trial and for five weeks after the last administration of entrectinib.

⁃ G. Male patients with partners who are women of childbearing potential are eligible provided that they agree to the following, from the first administration of entrectinib, throughout the trial and for three months after the last administration of entrectinib:

• Agree to take measures not to father children by using a barrier method of contraception (condom plus spermicide) or to sexual abstinence.

• Non-vasectomised male patients with partners who are women of childbearing potential must also be willing to ensure that their partner uses a highly effective method of contraception as in F above.

• Male patients with pregnant or lactating partners must be advised to use barrier method contraception (e.g condom) to prevent drug exposure of the foetus or neonate.

⁃ All male patients must refrain from donating sperm for the same period.