ASCO Annual Meeting: Promising Cancer Treatment Options Using Receptor and Protein Targets

2016 ASCO Annual Meeting: Collective Wisdom #ASCO16
June 5, 2016
Greg Guthrie, ASCO staff

The American Society of Clinical Oncology (ASCO) Annual Meeting is here! From June 3 to June 7, more than 30,000 oncology professionals from around the world will meet to discuss the latest research in state-of-the-art treatments, new therapies, and patient care.

The theme for this year’s meeting is Collective Wisdom: The Future of Patient-Centered Care and Research. According to ASCO President Julie M. Vose, MD, MBA, FASCO, “the patient is at the center of a very complex system trying to assist them through their journey of cancer care. I selected the theme of collective wisdom to represent the importance of the multimodality care that is necessary for our patients.”

Read below to learn about some of the research released today. Plus, find more of today’s highlights from the ASCO Annual Meeting

  • Immunotherapy: Research and promise

    • Atezolizumab helps patients with advanced bladder cancer

    • Stomach cancer antibody can lengthen life in patients

  • Searching for targets: Targeted therapy in cancer research

    • Early promise in treating small cell lung cancer

Immunotherapy: Research and promise

The emerging field of immunotherapy has made a lot of people very excited in the world of cancer treatment. And it should, because immunotherapy allows a person’s own immune system to fight his or her cancer, sometimes yielding surprisingly effective results. In 2016, ASCO named immunotherapy the Clinical Cancer Advance of the Year.

There are many forms of immunotherapy. The video below shows how 1 method of immunotherapy, a monoclonal antibody that blocks the PD-1/PD-L1 pathway, works in melanoma and lung cancer.

Researchers continue to seek out and develop new immunotherapies that will work for people with cancer. Some of the latest advances are being described now at the ASCO Annual Meeting.

Atezolizumab helps patients with advanced bladder cancer share on twitter 

Patients with advanced bladder cancer who were treated with atezolizumab (Tecentriq) lived longer than patients who received the current standard treatment. Bladder cancer typically affects older adults; the average age of patients at the time of diagnosis is 70. The standard treatment is cisplatin-based chemotherapy; with this treatment median survival is 12 to 15 months. The median is the midpoint, which means that half of patients lived longer and half lived for a shorter time. However, for 30% to 50% of patients, cisplatin-based chemotherapy is not safe, usually because of the patient’s age, kidney health, and other medical issues.  These patients may receive carboplatin-based chemotherapy; median survival with this treatment is about 10 months. 

Atezolizumab is a monoclonal antibody that blocks the PD-L1 receptor on the surface of immune cells called T-cells. When this receptor is blocked, the T-cells can “see” the cancer cells and attack the tumor. Tumors shrank in 24% of patients who were treated with atezolizumab. Patients lived for a median of almost 15 months.

In addition, this immunotherapy had fewer severe side effects that caused patients to stop taking the medication. In this study, 6% of patients had to stop taking atezolizumab. In comparison, 20% of patients taking chemotherapy have to stop because of side effects.

What does this mean? For people who do respond to atezolizumab, this offers a chance of longer life. Atezolizumab was approved by the U.S. Food and Drug Administration (FDA) for certain patients in May 2016.

“Up to half of patients with advanced bladder cancer are too frail to receive the only known survival-prolonging treatment, cisplatin. There is really no standard treatment for such patients. We are encouraged to see that atezolizumab immunotherapy may help address this major unmet need.”

—lead study author Arjun Vasant Balar, MD, New York University (NYU) Langone Medical Center and NYU Perlmutter Cancer Center, New York, NY

Stomach cancer antibody can lengthen life in patients share on twitter 

A new antibody called IMAB362 holds promise for patients with advanced stomach cancer, also called gastric cancer. IMAB362 targets a protein called claudin18.2, which is found in many kinds of tumors, including stomach, pancreatic, lung, esophageal, and ovarian. When IMAB362 attaches to claudin18.2 on the surface of cancer cells, the immune system begins destroying cancer cells that are coated with the antibody.

The first treatment for people with advanced or recurrent stomach cancer is chemotherapy. In some cases, trastuzumab (Herceptin) is added to chemotherapy if the patient has a HER2-positive tumor. However, only 15% of stomach cancers are HER2 positive. In this study, chemotherapy only was compared to chemotherapy plus IMAB362.

For patients who received only chemotherapy, the disease worsened after a median of nearly 5 months, and median survival was a little more than 8 months. The median is the midpoint, which means that half of patients lived longer and half lived for a shorter time. IMAB362 kept the disease from worsening for longer, a median of just under 8 months. IMAB362 also increased the median overall survival to 13 months. Among patients with the highest levels of claudin18.2, the median overall survival was about 17 months with IMAB362, compared to 9 months with chemotherapy alone.

What does this mean? This therapy nearly doubles how long a patient can survive with stomach cancer if the tumor has high levels of claudin18.2. The antibody is also promising because it may be effective in treating other types of cancer. The researchers are planning to study its use in patients with pancreatic cancer.

“As claudin18.2 is abundant in gastric tumors, we estimate that half of all patients with advanced gastric cancer may be candidates for this new treatment. In addition, this unique target is not present in any healthy tissues except the lining of the stomach, thereby minimizing treatment side effects.”

—lead study author Salah-Eddin Al-Batran, MD, Institute of Clinical Cancer Research, Nordwest Hospital, Frankfurt am Main, Germany

Searching for targets: Targeted therapy in cancer research

Targeted therapy uses drugs to stop cancer from growing and spreading. They work by targeting specific genes or proteins. These genes and proteins are found in cancer cells or in cells related to cancer growth, like blood vessel cells. Targeted therapy can be considered a form of precision medicine.

Early promise in treating small cell lung cancer share on twitter 

The targeted therapy in this study was an antibody drug conjugate (ADC) called rovalpituzumab tesirine (Rova-T). ADCs are large molecules that can contain other anticancer drugs. When ADCs attach to a cancer cell, the ADC goes inside. Then, the anticancer drug starts working to destroy the cancer cells. Rovalpituzumab tesirine includes an anti-DLL3 antibody and a cancer-destroying agent that damages tumor DNA.

Small cell lung cancer (SCLC) is very difficult to treat and accounts for 10% to 15% of lung cancer. Most patients live for a year or less after diagnosis. About two-thirds of patients with SCLC have high levels of the DLL3 protein on the surface of cancer cells. Healthy adult tissues, however, have virtually no DLL3 on the surface of those cells. This means that rovalpituzumab tesirine is very likely to target and affect only SCLC cells in the body.

In this study, 74 patients with SCLC that had worsened after treatment were given the ADC. Among the patients with the highest levels of DLL3 in the tumor, tumors shrank in 39% of patients and stopped growing in 89% of patients. Across the entire study group, 18% of patients had their tumors shrink and 68% of patients had their cancer stop growing.

What does this mean? This was a small, early clinical trial, but it has shown that DLL3 may be a promising target for treating SCLC. Future larger studies are needed to see if DLL3-targeted treatments can help a lot of people with SCLC live longer.

“We’ve seen too few successes in recent years for small cell lung cancer, which makes these early signs of efficacy all the more encouraging. Although these results are preliminary, rovalpituzumab tesirine seems to be the first targeted therapy to show efficacy in small cell lung cancer, and we may have identified DLL3 as the first predictive biomarker in this disease.”

—lead study author Charles M. Rudin, MD, PhD, Memorial Sloan Kettering Cancer Center, New York, NY

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