The recent U.S. approval of a new low dose of colchicine 0.5 mg (Lodoco; Agepha Pharma) with a broad indication for use in atherosclerotic cardiovascular disease (ASCVD) represents a completely new approach to treatment, specifically targeting inflammation as a driver of atherosclerosis.
The Food and Drug Administration granted colchicine a very broad label: to reduce the risk for cardiovascular events in adult patients with established ASCVD or with multiple risk factors for cardiovascular disease. But how will the drug be used in clinical practice?
“The idea of inflammation as a driver of atherosclerosis and cardiovascular risk has been around for decades, and it is very well known that atherosclerosis is an inflammatory process. However, treating inflammation is new as we haven’t had a specific agent targeting inflammation before, noted Michael Joseph Blaha, MD, director of clinical research, Ciccarone Center for the Prevention of Cardiovascular Disease at Johns Hopkins Hospital, Baltimore.
Dr. Blaha, who has been an unpaid scientific adviser to Agepha, added that the approval of low-dose colchicine “will open the door toward having a routine conversation about residual inflammatory risk in our patients; and we need to work out exactly how we do that.”
Dr. Blaha is not surprised by the FDA-approved indication for colchicine, pointing out that the main large-scale trial supporting its use in ASCVD, the LoDoCo-2 trial, included a similar broad population.
“I think the approval was appropriate as the indication should always follow the data. But I think how the drug will actually be used will depend on the context for different individual patients,” he said.
“The paradigm coming forward is the idea of residual risk that patients have after they been treated with the standard of care – which in most cases is a statin and blood pressure control – and what is driving that residual risk,” he noted. “If we think patients are still at high risk of recurrent cardiovascular events, we have to think what we will do next. This is where this drug will come in.”
Dr. Blaha pointed out that there are now multiple options for reducing residual risk; he believes that it will depend on the profile of the patient as to which of those options is chosen first.
“If after high-dose statin treatment they still have raised LDL, then we can add another LDL lowering drug; or it might be diabetes and obesity that we want to address first; or elevated triglycerides. But now, we can also consider residual inflammatory risk if we think the patient has residual plaque inflammation,” he said. “So, colchicine will be one of several choices beyond a statin that we can think about as the next step for treating residual risk.”
Is CRP measurement necessary?
Though elevated levels of high-sensitivity C-reactive protein (hsCRP) is a marker of inflammation in ASCVD, the two main trials of colchicine in ASCVD, both of which showed large benefits of the drug, did not measure hsCRP, leading to questions as to whether measurement of this biomarker is necessary to select patients for colchicine treatment.
“Some clinicians will favor testing hsCRP and treating those with levels above 2 mg/L. I think that’s very reasonable,” Dr. Blaha said. “However, because hsCRP was not measured in the trials, I don’t think testing for this biomarker is mandatory to establish that there is inflammation,” he added.
“The label does not stipulate that CRP has to be measured. It is giving physicians latitude; they can measure CRP, or they don’t have to.”
Dr. Blaha added that clinicians need to think about what is driving residual risk in each individual patient: “If you think their other risk factors are well controlled but they are still having recurrent events, then we can consider colchicine as a way of reducing their residual risk which is likely being caused by inflammation.
“We are at a great place in cardiovascular medicine as we have several different options to use after a statin, and now we have this new therapy targeted at inflammation as well. While we can use all these options together, I think most clinicians will want to prioritize therapies by using the ones that they believe will reduce the residual risk the most in each individual patient,” Dr. Blaha explained.
‘An entire other axis driving atherosclerosis’
Paul Ridker, MD, director of the Center for Cardiovascular Disease Prevention at Brigham and Women’s Hospital in Boston, is one of the major players in the cardiovascular inflammation field and has helped develop hsCRP testing. He has similar views.
“This FDA approval is extremely important, as it will draw attention to the role of inflammation in atherosclerosis and the need to treat it,” he said.
“Physicians need to be aware that, yes, we need to lower cholesterol aggressively, but they also need to know that there is an entire other axis driving atherosclerosis – and that is inflammation. And until now, we haven’t had an FDA-approved drug to treat inflammation.”
Dr. Ridker stressed that he doesn’t want to undermine lowering lipids: “Therapies aimed at inflammation are not in competition with those aimed at lipid lowering. We know lipid lowering works. But now we have another approach as well. The challenge here is educating physicians on this new approach.”
Dr. Ridker said he already uses low-dose colchicine for patients whom he refers to as “frequent flyers”; those who keep coming back despite aggressive lipid lowering. “They have multiple angioplasties, bypass surgery, etc.”
Like Dr. Blaha, Dr. Ridker thinks that doctors should start using this drug in high-risk patients who are already on a statin and who have residual inflammatory risk: “[The] patient whose underlying biologic problem is inflammation [is whom] we really want to treat with this drug. That is where it is most likely to be highly effective and where the comfort level will be the greatest.”
He said that measurement of hsCRP is an appropriate way to select these patients.
“I think this is a great impetus to start having much wider CRP measurement so we can actually target this anti-inflammatory drug to the patients with residual inflammatory risk – those with hsCRP level above 2 mg/L,” he said, estimating that this could apply to around 30%-40% of patients with ASCVD who are already taking a statin.