DETERMINE Treatment Arm 4: Trastuzumab in combination with pertuzumab in Adult, Teenage/Young adult and Paediatric patients with rare* cancers with HER2 amplification or activating mutations and in common cancers where HER2 amplification or activating mutations are considered to be infrequent.~*Rare is defined generally as incidence less than 6 cases in 100,000 patients (includes paediatric and teenagers/young adult cancers) or common cancers with rare alterations.~This treatment arm has a target sample size of 30 evaluable patients. Sub-cohorts may be defined and further expanded where promising activity is identified to a target of 30 evaluable patients each.~The ultimate aim is to translate positive clinical findings to the NHS (Cancer Drugs Fund) to provide new treatment options for rare adult, paediatric and TYA cancers.~OUTLINE:~Pre-screening: The Molecular Tumour Board makes a treatment recommendation for the participant based on molecularly-defined cohorts.~Screening: Consenting participants undergo biopsy and collection of blood samples for research purposes.~Treatment: Participants will receive trastuzumab and pertuzumab until disease progression, unacceptable toxicity or withdrawal of consent. Participants will also undergo collection of blood samples at various intervals while receiving treatment and at EoT.~After completion of study treatment, patients are followed up every 3 months for 2 years.~THE DETERMINE TRIAL MASTER (SCREENING) PROTOCOL:~Please see DETERMINE Trial Master (Screening) Protocol record (NCT05722886) for information on the DETERMINE Trial Master Protocol and applicable documents.
This clinical trial is looking at a combination of drugs called trastuzumab and pertuzumab. This combination of drugs is approved as standard of care treatment for adult patients with metastatic breast cancer. This means it has gone through clinical trials and been approved by the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK.~Trastuzumab and pertuzumab work in patients with these types of cancers which have a molecular alteration called HER2 amplification or HER2 activating mutation.~Investigators now wish to find out if it will be useful in treating patients with other cancer types which are also HER2 amplified or HER2 mutated. If the results are positive, the study team will work with the NHS and the Cancer Drugs Fund to see if these drugs can be routinely accessed for patients in the future.~This trial is part of a trial programme called DETERMINE. The programme will also look at other anti-cancer drugs in the same way, through matching the drug to rare cancer types or ones with specific mutations.