Deep vein thrombosis, or DVT, is a potentially life-threatening blood clotting condition. If you’ve ever had DVT or been at risk for this condition, you’ve likely been given drugs to help break up the clot and to prevent future clots from forming.
Today, doctors often prescribe new blood-thinning medications -- approved within the past decade -- that have helped improve DVT care. But researchers are working on new DVT treatments that can do an even better job at treating and stopping this serious condition.
Many of the new DVT drugs in development improve on one of the main side effects of blood thinners today: unwanted bleeding. This can happen in older medications like warfarin or some of the newer drugs, such as apixaban (Eliquis), approved in 2014, or rivaroxaban (Xarelto), approved in 2012. People with cancer are especially at risk from this side effect. So studies have focused on finding new drugs that will better work for them. Researchers also hope to come up with treatments that can prevent post-thrombotic syndrome, which happens after DVT in up to 50% of patients.
Here’s a look at promising drugs that are being tested, often in clinical trials, and which your doctor may be able to prescribe in coming years.
New DVT Drugs Include Factor XI Inhibitors
Several new drugs being studied today target a blood clotting factor called XI, a protein that tells your body to start making clots, which can lead to DVT. These drugs bind to this clotting factor and “inhibit” or stop it from switching on. That prevents clots, such as those that happen with DVT.
Abelacimab. A recent study in the New England Journal of Medicine looked at how abelacimab, a monoclonal antibody, worked in patients having knee replacement surgery. Researchers compared its results to people who took a current drug, enoxaparin (Lovenox), a form of heparin. They found that patients who got abelacimab were less likely to develop blood clots after surgery than those who got enoxaparin.
Abelacimab also is being compared with other current DVT drugs, such as apixaban and dalteparin, in the treatment of cancer-associated blood clots. Researchers expect the trials to be finished in 2024.
Osocimab is another monoclonal antibody being studied to see how well it prevents clotting. In a study in the Journal of the American Medical Association, osocimab was compared with enoxaparin in patients having knee surgery. The study looked at different doses of osocimab and whether it was given before or after surgery. Osocimab was found to be comparable to enoxaparin at some dosages, while at others, it was considered better.
Osocimab is being studied in a clinical trial with patients in kidney failure requiring dialysis. Researchers estimate the trial will be finished in June 2022.
Milvexian was studied in patients having knee replacement. Researchers found that people who took two doses a day had a much lower rate of blood clots after surgery than expected (12%). There also was low risk of bleeding. A clinical trial in Utah is testing milvexian’s effects on healthy people when given different doses of the drug. The study should finish in August 2022.
Another New Drug Type: Tissue Factor Pathway Inhibitors (TFPIs)
In addition to drugs that target factor XI, others use a different way to fight DVT. These drugs are called tissue factor pathway inhibitors (TFPIs).
One example of a TFPI drug is rNAPc2, which stands for recombinant nematode anticoagulant protein C2. Scientists discovered this substance in a hookworm, an intestinal parasite. It disrupts the clotting process, which helps stop DVTs.
This new TFPI drug was fast-tracked by the FDA in 2020 for its use in blood thinning. The drug was studied in a clinical trial looking at how effective it could be in preventing blood clots in people with COVID. But results have not yet been posted. Mainz University Medical Center in Germany is teaming up with U.S. firm ARCA Biopharma to make rNAPc2 for use in COVID-19 patients, and broader use to treat other blood clotting conditions.
New DVT Uses for Existing Drugs
Some DVT researchers are studying drugs that are used for other purposes to see if they can prevent or treat blood clots.
Statins are commonly prescribed to lower your cholesterol. They also have been studied to see if they can help prevent DVT. At least one type, rosuvastatin (Crestor), is being studied in several clinical trials. For example, one study is looking to see how it can help ovarian cancer patients after surgery when paired with enoxaparin. Another is testing its use in avoiding the DVT side effect post-thrombotic syndrome.
Asthma medicine. Researchers at the University of Birmingham in England are studying whether allergy medication can be repurposed to prevent blood clots. Earlier studies have shown that blocking the creation of mast cells – large cells close to blood vessels – in mice might play a role in DVT prevention.
Existing asthma medication also targets mast cells. A 5-year study announced in 2019 is looking at whether humans respond the same way, without excess bleeding. This could lead to new medication or new uses of asthma medication to help prevent DVT.
Expanded Role for Current Blood-Thinning Drugs
The FDA has recently expanded approvals for two of the newer blood thinners on the market, allowing them to be used in children.
Rivaroxaban (Xarelto) now can be used in children under age 18 who have received injectable or IV treatment for blood clots for at least 5 days, according to FDA guidelines issued in December 2021. The drug can also be used to prevent clots in children 2 years old and older who have had a certain type of heart surgery called the Fontan procedure. A new liquid version of the drug a child can drink was approved, too.
Certain restrictions still apply for very small (under 5.7 pounds) or very young children (premature infants less than 6 months old). Also, it isn’t to be used in patients with active, major bleeding, because this drug can increase the risk of bleeding.
Other common side effects in children include coughing, vomiting, and inflammation of the stomach and intestine.
Dabigatran etexilate mesylate (Pradaxa) became the first approved oral blood-thinning medication for children in June 2021. The FDA approved “oral pellets” for children from 3 months to 11 years old to treat clots, and capsules for kids 8 and older. The children must have been treated for their blood clot with injected blood thinner for at least 5 days before treatment.
If you are interested in finding out more about new DVT drugs, including those that may be available to you in clinical trials, talk with your doctor. You can also track new drugs in development at the government’s clinical trials website, clinicaltrials.gov.