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Immune Checkpoint Inhibitors Are Boosting the Cancer Battle

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Nov 24, 2021.

What is Immunotherapy?

You've probably heard about the new groundbreaking type of "immunotherapy" drugs used to treat and kill cancer. Immunotherapy has been the subject of numerous news articles and TV specials. In fact, in October 2018 James P. Allison, PhD from the MD Anderson Cancer Center in Houston won the 2018 Nobel Prize in Physiology/Medicine for his breakthrough discoveries in this type of immunotherapy.

These drugs aren't some kind of obscure therapy, either. Former President Jimmy Carter received one of these medications, Keytruda (pembrolizumab) -- fortunately with great success. He received Keytruda for his skin cancer (also called metastatic melanoma) that had spread to his brain. These medications are now established therapy in the toolbox of cancer treatments.

The groundbreaking new treatments are adding months -- or even years -- to the lives of patients who have cancer. In fact, for some patients, their tumors seem to disappear. One cancer immunotherapy class is called the Immune Checkpoint Inhibitors, and they are quickly gaining new approvals for many different cancer types.

Linked: Our Immune System and Cancer

Our immune system is simply an amazing piece of human biology. The immune system helps to guard the body from infections due to bacteria, viruses, and yes, even cancer. This immune gatekeeper has a memory, too, and it can remember and 'recognize' when foreign invaders, such as cancer, attempt to inhabit our body.

However, the immune system is not perfect in fighting these intruders, and researchers are making great progress to learn why. It appears some tumors can 'turn off' the ability of cancer-fighting cells such as T-cells (a type of white blood cell) to attack these unwelcome guests.

But options new immunotherapy drug class called "Immune Checkpoint Inhibitors" are fighting back.

Drugs in this group include agents such as:

What makes them so special? How do these novel agents work?

Cancer Types Targeted by Immunotherapy

If you've been affected by cancer -- either yourself or a family member -- take time to learn more about these breakthrough treatments. Advances are being made in cancers such as:

Many other types of cancer are also under research or approved. While not every patient will have a response, it is important to investigate your alternatives with your doctor. Joining a groundbreaking research trial might even be an option. This could give you the opportunity to use an investigational medication that is not available otherwise.

Immune Checkpoint Inhibitors: Releasing the Brakes

The immune system needs to be able to tell the difference between foreign invaders and heathy tissue so that our cells and organs are not mistakenly attacked. To do this, our immune system has a set of "brakes", like a bike, that can help it to stop and go.

  • When the immune system "brakes" are "off", it's active and attacks cells that are considered foreign invaders such as cancer. Our immune system is very good at this, but cancer is sneaky and can fool the "brakes".
  • When the T-cell is stopped ("brakes" are on) it can't fight the cancer.

However, the Immune Checkpoint Inhibitors release the "brakes" so the T-cells can now "go" find and kill the cancer cells.

Some of these checkpoints are called PD-1, PD-L1, and CTLA-4 receptors, which are protein receptors or ligands on cell surfaces. Drugs that target these checkpoints to turn "off" the "brakes" hold great promise and are now used to fight many types cancer.

FDA-Approved Immune Checkpoint Inhibitors and Uses

The number of cancers approved for Immune Checkpoint Inhibitors have skyrocketed in recent years. These medicines now play a major role in cancer treatment for some of the most advanced cancers.

Commonly known examples include:

  • Yervoy (ipilimumab) from Bristol Myers Squibb targets CTLA-4 and is used to treat at least 6 cancer types, including advanced melanoma, renal (kidney) cell carcinoma, and colorectal cancer, among many others.
  • Keytruda (pembrolizumab) from Merck, targets PD-1 ligands and is used to treat over 14 different cancers, including: advanced melanoma; non-small cell lung cancer, head and neck cancer, Merkel Cell Carcinoma (a rare type of skin cancer), renal (kidney) cell carcinoma, and endometrial cancer.
  • Opdivo (nivolumab) from Bristol-Myers Squibb, targets PD-1 and is used for advanced melanoma, non-small cell lung cancer, renal (kidney) cell carcinoma, Hodgkin's lymphoma, and at least 8 other cancer types.
  • Tecentriq (atezolizumab) from Genentech, is a commonly used ICI and targets PD-L1. Uses include bladder cancer, non-small cell lung cancer, breast cancer, small cell lung cancer, melanoma and hepatocellular (liver) cancer.

Approved Immune Checkpoint Inhibitors (ICI) and Uses (continued)

  • Bavencio (avelumab) blocks PD-L1 and is used for Merkel cell carcinoma (a rare type of skin cancer), urothelial (bladder or urinary tract) cancer, and renal (kidney) cell carcinoma, in combination with Inlyta (axitinib).
  • Imfinzi (durvalumab) targets PD-L1 and is approved non-small cell lung cancer, and small cell lung cancer. The use for advanced bladder cancer was withdrawn in 2021 by AstraZeneca as the drug did not meet primary endpoints in required Phase III trials based on accelerated approval.
  • Libtayo (cemiplimab-rwlc) from Sanofi and Regeneron, was first approved in Sept. 2018. Libtayo targets the PD-1 cellular pathway, and is approved to treat a type of skin cancer known as advanced cutaneous squamous cell carcinoma (CSCC). In 2021 Libtayo was also approved to treat advanced basal cell (skin) carcinoma and non-small cell lung cancer
  • GSK’s Jemperli (dostarlimab-gxly) is a programmed death receptor-1 (PD-1) blocking antibody used to treat adults with mismatch repair-deficient (dMMR) endometrial cancer that has returned or cannot be removed by surgery.

Many combined uses of checkpoint inhibitors have been cleared by the FDA, as well as the combination with chemotherapy. Quite often these drugs are used after traditional cancer treatment has failed, but as research advances they are increasingly gaining first-line indications.

Yervoy (ipilimumab)

Yervoy, known generically as ipilimumab, is a monoclonal antibody that attaches to the T-lymphocyte antigen 4 (CTLA-4) protein receptor to inhibit CTLA-4. This releases the "brakes" and helps to activate our immune system to attack cancer.

Melanoma is more likely to spread (metastasize) than other forms of skin cancer, and is increasing in incidence. Yervoy was the first immune checkpoint inhibitor to be FDA-approved in March of 2011 for the treatment of late-stage melanoma (skin cancer).

It is also approved in combination with Opdivo (nivolumab) to treat renal cell carcinoma, colorectal cancer, non-small cell lung cancer, hepatocellular (liver) cancer, certain types of melanoma and malignant pleural mesothelioma.

Yervoy is given as an intravenous (IV) injection. Review Yervoy dosing here.

Common reported side effects include rash, diarrhea, fatigue, itching, headache, nausea and weight loss. Severe immune-mediated side effects can also occur with Yervoy, which may result in the need for treatment discontinuation.

Opdivo (nivolumab)

Opdivo, known generically as nivolumab, is also an immune checkpoint inhibitor. However, Opdivo acts at a different receptor than Yervoy, and is known as a programmed death receptor-1 (PD-1) blocking antibody.

Opdivo was first approved in December 2014 to treat advanced melanoma, but since then has been cleared by the FDA to treat amny cancers, including:

Plus, it has many uses in combination with Yervoy. Opdivo is given as an intravenous injection; view dosing here.

In 2020, BMS withdrew the use of Opdivo for small cell lung cancer as study endpoint requirements were not met for full FDA approval after initial accelerrated approval.

Common side effects can include rash, itching, cough, upper respiratory tract infections, and fluid retention (edema). Severe immune-mediated side effects, a problem with all of these drugs, can occur.

Keytruda (pembolizumab)

Keytruda, generic name pembolizumab, might sound familiar to you. First approved in September, 2014, this was the immunotherapy that former President Jimmy Carter received to fight off brain cancer due to metastatic melanoma (skin cancer that has spread). Since that time, Keytruda has been approved for over 20 other uses.

Like Opdivo, Keytruda is a PD-1 blocking antibody. Keytruda is FDA-approved to treat multiple advanced cancers, including (list not complete):

  • metastatic melanoma (including as a first-line agent)
  • non-small cell lung cancer (NSCLC)
  • first-line treatment of metastatic nonsquamous non-small cell lung cancer (NSCLC) irrespective of PD-L1 expression
  • Hodgkin's lymphoma
  • primary mediastinal large B-cell lymphoma
  • head and neck cancer
  • hepatocellular (liver) cancer
  • Merkel cell carcinoma (a rare form of skin cancer)
  • renal (kidney) cell carcinoma
  • esophageal cancer
  • squamous cell carcinoma

Keytruda is given via intravenous (IV) infusion, and its dosing can be reviewed here.

Common side effects you might encounter are: edema (water retention) fatigue, itching, constipation, diarrhea, rash, and nausea. Infusion reactions with flu-like symptoms such as chills, fever, headache and weakness may occur, as well as the immune mediated adverse reactions seen with other checkpoint inhibitors.

Tecentriq (atezolizumab) and Imfinzi (durvalumab)

Tecentriq, generic name atezolizumab was approved in May 2016 and was the first PD-1/PD-L1 inhibitor.

  • Tecentriq is approved to treat certain patients with local or metastatic urothelial (bladder) cancer.
  • Tecentriq is also approved by the FDA for treatment of certain types of advanced non-small cell lung cancer (NSCLC) and small cell lung cancer.
  • It has also been cleared to treat PD-L1-positive, metastatic triple-negative breast cancer, hepatocellular (liver) cancer, and melanoma.
  • Many of these use are in combination with other agents. See specific dosing recommendations here.

In studies, common side effects included fatigue, decreased appetite, nausea, urinary tract infection, fever, and constipation.

Another PD-L1 blocker, Imfinzi (durvalumab) from AstraZeneca, was FDA-approved in May 2017 for the treatment of patients with advanced urothelial carcinoma (bladder cancer), but this use was withdrawn in 2021 by the manufacturer as it did not meet Phase III endpoints. In Feb. 2018 it was approved for Non-Small Cell Lung Cancer, and in March 2020 for Small Cell Lung Cancer.

Review dosing for Imfinzi here.

Bavencio (avelumab)

Bavencio (avelumab), also a PD-L1 blocking antibody, received accelerated FDA-approval in March 2017 for the treatment of patients with metastatic Merkel cell carcinoma (MCC). Bavencio was the first FDA-approved treatment for metastatic MCC and is used in patients 12 years and older including those who have not received prior chemotherapy. Keytruda is now also approved for this type of skin cancer.

  • MCC is rare form of skin cancer most common in older patients. It appears as painless pink, red, or purple bump, often on the face, head or neck area.
  • Most patients can get the tumor removed surgically, but more than 30% will eventually develop disease recurrence.
  • Approval of Bavencio was based on a study of 88 patients with metastatic MCC who had previously received chemotherapy. In 33% of patients, complete or partial shrinkage of their tumors occurred, with a response lasting for more than 12 months in 45% of patients.
  • Common side effects include fatigue, muscle pain, diarrhea, nausea, infusion-related reactions, and rash, among others.

Bavencio is also approved to treat urothelial carcinoma (of the bladder, ureters and renal pelvis), and in combination with Inlyta (axitinib) as first-line therapy to treat advanced renal cell (kidney) carcinoma.

View Bavencio dosing specifics here.

Imfinzi (durvalumab)

Imfinzi (durvalumab) is an anti-PD-L1 in the same class of drugs as Tecentriq (atezolizumab) and Bavencio (avelumab). It was first approved in May 2017 for urothelial (bladder) cancer treatment, but that use was withdrawn by the manufacturer in 2021.

In February 2018, FDA approved Imfinzi -- in patients with stage III non-small cell lung cancer (NSCLC) whose tumors cannot be removed surgically and whose cancer has not progressed after treatment with chemotherapy and radiation.

  • In clinical trials, the lung tumors did not have significant growth (known as progression-free survival) for 16.8 months compared with 5.6 months for placebo.
  • In March 2020, it also gained approval for small cell lung cancer (SCLC) treatment.
  • In studies, common side effects included cough, fatigue, inflammation in the lungs, respiratory tract infections, difficulty breathing, and rash.

View Imfinzi dosing here.

Jemperli (dostarlimab-gxly) from GSK

In April 2021, the FDA gave accelerated approval to GSK’s Jemperli (dostarlimab-gxly), a programmed death receptor-1 (PD-1) blocking antibody used to treat adults with mismatch repair-deficient (dMMR) endometrial cancer that has returned or cannot be removed by surgery. An FDA-approved test determines if the cancer is dMMR.

Jemperli works by binding to the PD-1 receptor and blocking interaction with the ligands PD-L1 and PD-L2. Jemperli is given as an intravenous infusion.

  • Approval was based on the ongoing Phase 1 GARNET trial of 71 evaluable patients that demonstrated an overall response rate of 42.3%, with a complete response of 12.7% and a 29.6% partial response rate.
  • Of those that responded, 93.3% demonstrated a duration of response (DOR) of 6 months or more. After 14.1 months, the median DOR was not reached.

The most common side effects in at least 20% of patients included fatigue or weakness, nausea, diarrhea, low red blood cells to carry oxygen (anemia), and constipation.

How Well Do Checkpoint Inhibitors Work?

Some, but not all people, can have a positive response with checkpoint inhibitors. How well they work for an individual patient will be based on many factors:

  • their type of cancer
  • whether they express certain genetic markers on their tumors
  • their overall health at the time of treatment
  • previous cancer treatments
  • their ability to tolerate the side effects of the medication.

In some patients, tumors have regressed and disappeared with checkpoint inhibitors. But this does not necessarily mean they are "cured", that the cancer won't return, or that everyone will respond.

Some longer-term studies are showing good results. For example, results from the KEYNOTE-024 study for Keytruda when used to treat advancd non-small cell lung cancer show that at 5 years, the overall survival rate was twice as high for patients who received Keytruda (31.9%) compared to a chemotherapy regimen (16.3%). Keytruda also led to a median overall survival of 26.3 versus 13.4 months in the chemotherapy group.

But treatment results can be variable -- cancer treatment is always very individual. It's important to discuss your expected treatment outcomes with your doctor.

Other Types of Cancer Immunotherapy

Research is very active in the area of cancer immunotherapy treatments. Immune checkpoint inhibitors are only one type of immunotherapy for treating cancer. Many other types of immunotherapy exist, some still under research in clinical trials and not yet approved:

Is An Oral Checkpoint Inhibitor On the Horizon?

Currently, all checkpoint inhibitors are monoclonal antibodies that require intravenous (IV) infusion. However, oral checkpoint inhibitors are under research by Curis Inc.

Toxicology studies show them to be safe when given in a once-daily oral dosing regimen. The manufacturer is currently investigating two agents, CA-170 and CA-327 in patients with advanced solid tumors and lymphomas.

CA-170 is called a PD-L1/VISTA antagonist. Currently, no VISTA antagonist immune checkpoint inhibitors are approved, so this would be a new immuno-oncology mechanism for checkpoint inhibitors.

  • CA-170 is a first-in-class, oral, small molecule antagonist of the immune checkpoints VISTA and PD-L1. CA-170 is currently undergoing investigation in a Phase 1 clinical trial in patients with advanced solid tumors and lymphoma, according to the manufacturer.
  • Early studies in with CI-8993, a V-domain Ig suppressor of T-cell activation (VISTA) negative checkpoint ligand are also ongoing. Pancreatic cancer, mesothelioma and prostate cancer are characterized by high levels of VISTA.
  • Another oral agent is in early stage research. CA-327 is an oral, first-in-class antagonist of the immune checkpoints PD-L1 and T cell immunoglobulin and mucin domain 3 (TIM3), also from Curis.

Combining Checkpoint Inhibitors

Metastatic melanoma is particularly aggressive, and the use of dual immune checkpoint inhibition is a novel approach to treat cancer. Opdivo and Yervoy are immune checkpoint inhibitors that target different but complementary checkpoint pathways (PD-1 and CTLA-4). Future research will also focus on combining treatments with different pathways. Studies are also looking at the possibility of combining CAR T cell therapy with checkpoint inhibition to extend the activity of CAR T cell therapy.

In January 2016, the combined use of Opdivo and Yervoy was FDA-approved for unresectable (not able to be removed with surgery) or metastatic (spreading in the body) melanoma regardless of BRAF (genetic) mutational status. The Phase III study, known as the CheckMate-067, was the first study to show the success of combining two immunotherapies.

In the study, the Opdivo + Yervoy regimen prolonged progression-free survival (PFS; survival time without the melanoma worsening) by a median of 11.5 months. Opdivo used alone (monotherapy) could prolong PFS by a median of 6.9 months, with 2.9 months for Yervoy used alone. A complete response (cancer undetectable) was seen in 8.9% of patients receiving the combined regimen.

Other approved combined uses of Opdivo + Yervoy include certain forms of melanoma, metastatic colorectal (bowel) cancer, renal cell (kidney) carcinoma, hepatocellular (liver) cancer, and mesothelioma.

Rare safety issues with the combined use of Opdivo + Yervoy, such as serious heart side effects, were reported in Nov. 2016: sudden cardiac arrest and rapid heartbeat with organ failure were fatal.

How Can I Learn More About Immunotherapy Clinical Trials?

Your doctor might recommend that you consider enrollment is one of the many ongoing clinical trials evaluating immunotherapy. Or maybe you first want to look for one yourself?

  • This might give you the ability to receive a medication that you could not otherwise obtain.
  • It's important to talk to your health care providers about the risks and benefits of clinical trials and if it might be a possibility. However, joining a clinical trial is not always the right choice for everyone.

To learn more about available clinical trials, you can look at the National Cancer Institute's (NCI) Clinical Trial Finder on their website. Here you can search by cancer type, zip code, and even age to help further define which trials might be right for you. Your doctor might be able to recommend other clinical trials, too.

Cancer Is Smart. But We Are Smarter.

Cancer is very clever. It can learn how to evade the natural systems we have in our bodies that are there to protect us. It has learned how to dodge detection by our immune system. But over many years, researchers have toiled to learn about the immune system and how it's linked to cancer. Now this hard work is paying off.

To stay up-to-date with the latest news and approvals for cancer immunotherapy, consider these options:

  • Joining the Cancer Support Group
  • Join individual groups that discuss new immunotherapies like Keytruda or Opdivo.
  • Ask questions, lend support, and raise awareness to those who may have similar cancer concerns as yours.

Finished: Immune Checkpoint Inhibitors Are Boosting the Cancer Battle

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.