Epidemiologists estimate that 12% of the population suffers from migraine headaches, about 18% of women and 6% of men. About 3.5% to 4.0% of the general population, the most severe cases, suffer in a class all by themselves. These individuals are categorized as having high frequency migraine, a debilitating condition that encompasses two classifications, chronic migraine (15+ migraine days per month) and high frequency episodic migraine (8 to 14 migraine days per month). More than 18 million patients suffer from high frequency migraine in the G7 nations alone. Approximately 15% of of migraineurs (totaling 1.7% of the total population) suffer from chronic migraine, a condition in which a patient is diagnosed with 15 or more migraine headache days per month. The majority of chronic migraine patients are more or less disabled and have trouble dealing with everyday routines due to their pain and other symptoms. The cost to society is considerable; between lost work days and the direct cost of treatment, migraine costs more than $17 billion to the US economy every year, according to a 2005 study, which equates to $21 billion in 2014 dollars.
The nearly as debilitating condition known as high frequency episodic migraine affects an additional 1.7% (or more) of the population. These patients experience 8-14 migraine headache days per month. Every year, an estimated 2.5% of patients in this category will progress to chronic migraine.
For both chronic migraine and high frequency episodic migraine, the need for more than an acute remedy, but a drug that will significantly reduce headache frequency, severity and duration. Current preventative treatments have shown low efficacy, however, and acute treatments have shown serious and sometimes dangerous side effects when used as often as high frequency migraine patients need them.
Low Efficacy of Preventive Treatments
Both of these highly disabling conditions, together referred to as high frequency migraine, are considered extremely difficult to treat by neurologists and PCPs. According to a Decision Resources 2014 migraine study, “interviewed experts agree that the highest unmet need in migraine treatment is for prophylactic therapies with improved efficacy and/or tolerability. However, few prophylactic therapies are in development, and we do not forecast the launch of any emerging prophylactics during our forecast period [2012 – 2022].”
No current therapies for high frequency migraine are considered broadly effective for prophylaxis, with most therapies providing a benefit of approximately 25 – 30% fewer headache days per month (offset by a placebo rate averaging about 17%). This includes off-label uses of drugs including topiramate (antiepileptic), propranolol (beta blocker), amitriptyline (tricyclic antidepressant), and verapamil (calcium channel blocker). The only FDA-approved treatment specifically for chronic migraine in the U.S. is onabotulinumtoxinA, which is marketed by Allergan as Botox®. The majority of patients stop using currently available prophylactic therapies due to inadequate efficacy and/or side effects.
Additionally, virtually all high frequency migraine sufferers must rely on prescriptions for acute relief, including triptans, opioids and over the counter drugs, primarily NSAIDs and other pain relievers. All carry side effects, ranging from mild to serious, including the risk of triggering rebound headaches. All acute drugs taken to often can produce another set of issues, including physiological dependence and a condition referred to as medication overuse headache, or MOH. MOH is very common among high frequency migraineurs.
Trigemina’s TI-001 therapy, now in Phase 2 clinical trials, is showing promising efficacy both in reducing headache frequency and allowing trial participants to greatly reduce their use of acute medications for pain relief.