Several times a year, leading cancer researchers gather to present and discuss the latest advancements. Biotech companies seek to gain top billing at these prominent medical conferences to highlight their results. Company stock prices can react dramatically depending on the data and whether it lived up to expectations. These have become must-attend events for healthcare analysts and institutional investors seeking to gain an edge.

For everyday investors who don't have the luxury of attending, we have highlighted three companies presenting data this weekend at the European Society of Medical Oncology Congress in Barcelona.  

Cancer research

Photo by Ousa Chea

1. Amgen's AMG 510 is a potential blockbuster in the making

Atop the list of clinical trial updates not to miss is the on-going Phase 1 results with AMG 510, a KRAS-inhibitor in development by Amgen (NASDAQ:AMGN). KRAS, once thought to be an undruggable cancer target, now has what appears to be a formidable foe, at least for a specific variant of the protein. AMG 510, which specifically targets that mutation of KRAS, debuted on the scene when data in lung cancer were presented in June. Amgen's stock responded by rising roughly 18% since then.

This Saturday will reveal the first glimpses of AMG 510's activity in two more types of cancer. David Reece, Amgen's executive vice president of research and development said, "We will report the first responses in advanced colorectal and appendiceal cancers at the upcoming congress." In the cancer field, responses refer to the degree of tumor shrinkage in each patient due to treatment. The keys to watch for are the number of patients responding and the frequency and severity of side effects. Positive data should continue to propel Amgen's stock.

2. A positive update from Immunomedics could lead to a repeat stock rise

Immunomedics (NASDAQ:IMMU) will report updated data on its drug sacituzumab govitecan from an on-going Phase 2 clinical trial for patients with metastatic urothelial cancer. These are very sick patients whose cancer continues to grow despite receiving one or two prior treatments. In February 2019, Immunomedics presented interim data on 45 patients showing an overall response rate of 31% and a median duration of response of 12.6 months. The progression-free survival was 7.3 months.

These results fueled a 30% increase in the stock price over the following month. Today the stock is trading for about the same as it was prior to the February announcement. We may see a repeat if the updated news on Saturday is deemed impressive by investors.

3. Zymeworks has a novel approach to a well-known cancer target

Zymeworks (NYSE:ZYME) plans to present single-agent data on its lead drug candidate ZW25, a drug that targets two variants of the gene HER2. HER2 is a well-known driver of certain cancers and the target of several approved drugs including Herceptin, the $7 billion a year cash cow marketed by Roche (OTC:RHHBY). On Saturday, investors will learn the latest on ZW25's safety and efficacy in patients with gastroesophageal, colorectal, biliary tract, gynecological and other cancers.

Zymeworks stock has steadily risen 25% this year. As it is smaller and earlier stage than either Amgen and Immunomedics, positive data could cause a more dramatic stock reaction in either direction. ZW25 pursues a well-defined cancer target. However, substantial benefits to patients will be required to take market share from entrenched therapies.

Stay tuned for stock-moving news in cancer

These are just a few of many updates that will be presented in Barcelona at the ESMO conference this weekend. While response rates correlating to tumor shrinkage are encouraging, stronger indicators include duration of response, progression-free survival, and overall survival time. The data from Amgen, Immunomedics, and Zymeworks are all still relatively early but don't tell that to investors who will be hanging on to every word about the clinical trials.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.