By Marti Webb Slay

Ascension St. Vincent’s is one of only two sites in the state testing new anticoagulant treatments for patients with AFib who cannot take blood thinners. They are enrolling patients in the trial, which is showing very promising results, according to principal investigator Alain Bouchard MD, cardiologist.

“AFib is probably one of the most prevalent heart diseases, particularly as our population ages. There are currently about 6 million people with AFib, and it’s predicted to be 12 million by 2030, so very significant prevalence,” he said.

Since AFib increases the risk of stroke by five times, and AFib patients who have a stroke tend to have higher disability and increased mortality, most patients with AFib are candidates for anticoagulants. 

“There are certain things we have to balance, however, such as the risk of stroke versus the risk of bleeding. For example, a lot of our patients who are older have coronary disease and take an aspirin, also have arthritis and take a medication for that. Certain patients have abnormal kidney disease or diabetes. All of a sudden, their risk of bleeding increases,” Bouchard said.

This trial is an effort to find safer drugs that balance the risk of stroke with the risk of bleeding, to better treat patients at risk for both.

“Years ago, all we had was warfarin. For some patients you don’t have a choice: if you have a prosthetic heart valve, you need to have warfarin. But if you don’t have a prosthetic heart valve and you have AFib, there are better choices,” he said.

Studies done 20 years ago showed the efficacy of new drugs, such as Xarelto and Eliquis, factor Xa inhibitors. This current trial is looking at Factor XI inhibitors, and their ability to protect against stroke without increasing the risk of bleeding. “It may be a paradigm shift in how we treat patients with AFib,” Bouchard said.

Hemophilia C is a condition where patients are born without Factor XI. “We are trying to imitate what nature brought us. These patients don’t form clots, and they don’t bleed,” he said.

The implications are significant and could mean patients on anticoagulants can have procedures without discontinuing their medication prior to the procedure. “You would remove this concern completely from clinical practice,” said Bouchard. “If you have a drug that is safe and lets you perform what you need to on a patient without interrupting anticoagulation medicine, that’s huge.”

There are three different Factor XI antagonists being studied, two of which are being conducted at St. Vincent’s.

Antisense Oligonucleotides
This trial is not being tested locally. The Phase II study of VTE prophylaxis entailed a weekly injection of Factor XI anticoagulant one to two weeks prior to surgery and up to a month following surgery. “These patients did very well. They compared it to Lovenox and found these patients didn’t have problems with bleeding at all, in much better fashion than just taking Lovenox after the surgery,” Bouchard said.

Antibody Abelacimab
“Abelacimab was studied In prevention of blood clot after hip surgery. In Phase II they found they were able to do the hip surgery after giving the medication as an injection once a month, and that prevented blood clot as effectively as Lovenox, yet had less bleeding. In another trial of patients with AFib, the study was stopped early, because they found out compared to Xarelto, the patients treated with abelacimab had less problem with bleeding and were as protected against stroke. In these Phase II studies, over 350 procedures were performed safely without bleeding complications. So we have very encouraging data,” he said.
The study of abelacimab at St. Vincent’s started this summer. “In this Phase III trial we are studying patients with AFib who have no option. These patients tend to be older, frail, with multiple falls. So far we have enrolled four patients. We plan to enroll 1900 patients over the next two years. We don’t expect any interaction with other medication. It can be given intravenously as well as under the skin, which is a big advantage. And it doesn’t require any dose adjustment, even in patients with chronic kidney disease,” Bouchard said.

Small Molecule
“This is a third way to block Factor XI,” he said. “The molecule we’ll be studying is milvexian, given as a pill twice a day. This medication has been given to patients with AFib in Phase II and was very effective compared to Eliquis.”
In Phase III they will continue comparing it to Eliquis, or apixaban, in patients with AFib. The study began this fall. They will follow these patients up to five years and enroll 15,000 patients worldwide. So far, over 2,000 have been enrolled.

“We are studying patients we see every day in the office,” Bouchard said. “There is no age limit and we will include patients with comorbidities. I’m very excited that finally, we have a study that includes the patients doctors see in everyday practice. And I’m hoping we enroll as many if not more women than men.”

Bouchard wanted to reassure referring physicians that they will continue to treat their patients as usual during the trial. “Doctors know their patients the best.” he said.

Physicians interested in referring patients to this study can contact Ashley Gilmore at (205) 212-6031, Ashley.gilmore@ascension.org.