This clinical trial focuses on patients with solid malignant tumors, which are a type of cancer that forms in solid organs or tissues. The study involves the use of a medication called pertuzumab, known by the brand name Perjeta, which is administered as a solution for infusion. Pertuzumab is used either on its own or in combination with other anti-cancer therapies. Another medication involved in the study is trastuzumab, known by the brand name Herceptin, which is also given as a solution for infusion. The purpose of the study is to continue providing pertuzumab therapy to patients who have previously participated in a related study and are still benefiting from the treatment.

Participants in this study will receive pertuzumab, and possibly trastuzumab, through an intravenous (IV) infusion, which means the medication is delivered directly into the bloodstream through a vein. The study is designed to monitor the safety and effectiveness of the treatment over time. Patients will be observed for any adverse events, which are unwanted effects that may occur during treatment. The study will also assess how long patients live without their cancer getting worse, known as progression-free survival, and overall survival, which is the length of time patients live after starting the treatment.

This study is an extension of a previous trial, meaning it continues the treatment for patients who were already receiving pertuzumab and were benefiting from it. The trial is open-label, which means both the researchers and participants know which treatment is being administered. The study aims to provide ongoing access to pertuzumab for those who need it, ensuring that patients continue to receive the potential benefits of the therapy.