This study is being done to answer the following questions: Is the chance of rectal cancer responding the same if chemotherapy alone is given before limited surgery compared to chemotherapy and radiation therapy given together before limited surgery? If radiation therapy is not given, is quality of life better?

This is a double-blind, randomized, multiregion, comparative phase clinical study designed to evaluate the efficacy and safety of HLX22 in combination with trastuzumab and chemotherapy as first-line treatment in patients with HER2-positive locally advanced/metastatic adenocarcinoma of the gastric and/or gastroesophageal junction (G/GEJ).Eligible subjects will be randomized to the two groups based on a 1:1 ratio. Enrolled subjects shall be treated with the study drug until the loss of clinical benefit, death, intolerable toxicity, withdrawal of informed consent, or other reasons specified by the protocol (whichever occurs first).

Zolbetuximab is being studied in people with cancer in and around the stomach or where the food pipe (esophagus) joins the stomach, called gastroesophageal junction (GEJ) cancer. Zolbetuximab with chemotherapy may be used to treat stomach and GEJ cancer when the cancer cells do not have a protein called HER2 (human epidermal growth factor receptor 2) on their surface (HER2-negative) but do have a protein called Claudin 18.2 (Claudin 18.2-positive). Zolbetuximab is thought to work by attaching to the Claudin 18.2 protein in their tumor, which switches on the body's immune system to attack the tumor. Certain stomach and GEJ cancers may be treated with immunotherapy, which helps the body's immune system fight cancer. This study will give more information about how well zolbetuximab works when given with an immunotherapy medicine called pembrolizumab and chemotherapy. In this study, adults with stomach cancer or GEJ cancer will either be given zolbetuximab with pembrolizumab and chemotherapy or a placebo with pembrolizumab and chemotherapy. A placebo looks like zolbetuximab but doesn't have any medicine in it.

The main aim of the study is to check how long people with stomach cancer and GEJ cancer live after treatment with zolbetuximab with pembrolizumab and chemotherapy compared to placebo with pembrolizumab and chemotherapy.

Adults with locally advanced unresectable or metastatic stomach cancer or GEJ cancer can take part. Locally advanced means the cancer has spread to nearby tissue. Unresectable means the cancer cannot be removed by surgery. Metastatic means the cancer has spread to other parts of the body. A tumor sample (biopsy) of their cancer will have the Claudin 18.2 protein, PD-L1 protein, and be HER2-negative. They may have been previously treated with certain standard therapies. People cannot take part if they need to take medicines to suppress their immune system, have blockages or bleeding in their gut, have specific uncontrollable cancers such as symptomatic or untreated cancers in the nervous system, or have a specific heart condition, or infections.

The study treatments are either zolbetuximab with pembrolizumab and chemotherapy, or placebo with pembrolizumab and chemotherapy. People who take part will receive just 1 of the study treatments by chance. The people in the study and the study doctors will not know who takes which of the study treatments. Study treatment will be given in 6-week (42-day) cycles. The study treatment is mainly given to people slowly through a tube into a vein. This is called an infusion. People will receive study treatment as follows: Zolbetuximab or placebo: 1 infusion every 2 or 3 weeks (2 or 3 infusions in a cycle) together with: Chemotherapy (1 of the following types of chemotherapy): 1. CAPOX (capecitabine and oxaliplatin): 1 infusion of oxaliplatin every 3 weeks (2 infusions in a cycle). People will also take 1 tablet of capecitabine twice a day for 2 weeks (14 days) at the start of each cycle (Day 1) and again in the middle of each cycle (Day 22). After 8 study treatments people will receive capecitabine only. 2. Modified FOLFOX6 or mFOLFOX6 (5-fluorouracil, folinic acid and oxaliplatin): 1 infusion every 2 weeks (3 infusions in a cycle). After 12 study treatments people will receive folinic acid and fluorouracil only, instead of mFOLFOX6. Pembrolizumab: 1 infusion every 3 or 6 weeks (1 or 2 infusions in a cycle). People can be in the study and will receive study treatment until their cancer worsens, they cannot tolerate the study treatment, or they need to start another cancer treatment. People may receive pembrolizumab for up to 2 years. People will visit the clinic on certain days to receive their study treatment and have health checks. The study doctors will check if people had any medical problems from taking zolbetuximab or the other study treatments. On some visits they will have scans to check for any changes in their cancer. People will have the option of giving a tumo

This Phase II/III trial will evaluate the what kind of chemotherapy to recommend to patients based on the presence or absences of circulating tumor DNA (ctDNA) after surgery for colon cancer.

This phase I trial studies the side effects and best dose of CA-4948 when given together with fluorouracil, leucovorin, oxaliplatin (FOLFOX) plus bevacizumab in treating patients with colorectal cancer that has spread from where it first started (primary site) to other places in the body (metastatic). CA-4948 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. The chemotherapy drugs used in FOLOX, fluorouracil and oxaliplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Leucovorin is used with fluorouracil to treat colorectal cancer. Bevacizumab is in a class of medications called anti-angiogenic agents. It works by stopping the formation of blood vessels that bring oxygen and nutrients to the tumor. This may slow the growth and spread of the tumor. Giving CA-4948 with FOLFOX plus bevacizumab may be safe, tolerable and/or effective in treating patients with metastatic colorectal cancer.