DETERMINE Trial Treatment Arm 04: Trastuzumab in Combination With Pertuzumab in Adult, Paediatric and Teenage/Young Adult Patients With Cancers With HER2 Amplification or Activating Mutations

THE PATIENT MUST FULFIL THE ELIGIBILITY CRITERIA WITHIN THE DETERMINE MASTER PROTOCOL (NCT05722886) AND WITHIN THE TREATMENT ARM 04 (TRASTUZUMAB AND PERTUZUMAB) OUTLINED BELOW\*

A. Confirmed diagnosis of a malignancy harbouring HER2 amplification, or an appropriate activating mutation as defined by the MTB, using an analytically validated next-generation sequencing method.

A HER2 amplification copy number between 5-9 will require an MTB discussion. A HER2 amplification copy number ≥10 will be fast-tracked for an MTB recommendation, unless there are any patient-specific individualities (such as multiple gene amplifications) that require MTB discussion.

B. Age 12 years or above.

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

Have a negative serum or urine pregnancy test before enrolment and;

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

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

II. progestogen-only hormonal contraception associated with or without inhibition of ovulation (oral, injectable or implantable)

III. intrauterine device (IUD)

IV. intrauterine hormone-releasing system (IUS)

V. bilateral tubal occlusion

VI. vasectomised partner

VII. sexual abstinence

VIII. male or female condom with or without spermicide

IX. cap, diaphragm or sponge with spermicide

Effective from the first administration of trastuzumab or pertuzumab (whichever is first), throughout the trial and for seven months after the last administration of trastuzumab or pertuzumab (whichever is later).

D. Male patients with partners who are women of childbearing potential are eligible provided that they agree to the following, from the first administration of trastuzumab or pertuzumab (whichever is first), throughout the trial and for seven months after the last administration of trastuzumab or pertuzumab (whichever is later):

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 an effective method of contraception as in C, 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.

E. Patients must be able and willing to undergo a fresh tissue biopsy at baseline and blood samples for translational research. Note that for patients with haematological malignancies or neuroblastomas, blood, bone marrow aspiration and/or trephine or lymph node biopsy samples may be taken.

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

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

What this study is about