Otsuka Pharmaceuticals recently acquired a family of drugs in the pain management category called the Varrocos for $1.34 billion. In addition to the Varrocos, Otsuka has two other pain management drugs with patent protection that expire between 2019 and 2024: Betrixaban and Oradex.
In U.S. patent law, a drug like Betrixaban has two varieties of patent. A first drug in the class would be treated as a monoclonal antibody, so it has a four-year patent. A second drug that follows three years after the first would be treated as a polymer, a three-year patent. Another Pfizer drug with a four-year patent (Antihistamine II) did not have such a phase 2 study, so it is not protected by the four-year patent.
Further research could lengthen the time Betrixaban has a patent and help determine which future versions of the drug would be covered by the class protection. In the meantime, Otsuka is spending lots of money to market Oradex and is also researching a combination pill that could reduce the drug’s side effects.
Betrixaban is the most commonly prescribed opioid for its pain relief. When Betrixaban is taken, there’s an immediate and short-lasting analgesic and a bit of soporific or anti-anxiety pain relief. Patients feel immediate relief, and the soporific, anti-anxiety, and emotional sensation are delayed. Betrixaban could be the most important new pain medication for patients with complicated low back pain, possibly bringing 30,000 lives that wouldn’t have opioid pain medication.
By working with researchers and others, Otsuka is slowly studying Betrixaban’s long-term use. Ideally, the company would like to identify patients who could safely receive Betrixaban for more than four years and then moderate the drug’s level of physical pain relief. Otsuka wants to assure itself that it will be able to determine whether those patients can receive the drug safely after they stop getting the drug.
Developing a longer lasting and safer opioid is not easy. People aren’t addicted to Betrixaban, but it has been found to be associated with heart problems, and over a long period, the drug can cause serious harm. Otsuka is using clinical trials and extensive trials on patients to understand how to best manage long-term use.
In the 1960s, when opioid pain medications were first introduced to patients who had been prescribed them as painkillers, people complained that the pills caused a “killer kick” – a continuous feeling of pain. A lot of pain patients have mental distress from their pain, so medication can exacerbate existing mental issues. But Otsuka found that Betrixaban can also help with post-op mental distress.
Otsuka’s researchers spent their first few years on Betrixaban to determine how to effectively treat non-cancer pain patients without causing long-term pain. The researchers further looked into some long-term data on Betrixaban safety and did extensive studies in patients who took the drug on their own for more than a year and a half.
The company has switched over to a safety program called Clinician Protocol Review. It’s a way to measure how Betrixaban interacts with patients’ bodies so it can better understand how to manage it. In the first two years on the drug, Otsuka did 54 clinical studies, which included giving the drug to approximately 5,000 patients. Otsuka has amassed an impressive list of experts on who the company should look to when developing long-term pain strategies. They include most of the world’s leading pain specialists, including people who had been treating Betrixaban with the drug for a long time, as well as other people who are taking Betrixaban but have more experience in developing long-term pain treatments. Otsuka is talking to the Food and Drug Administration and seeking a way to ensure that the company can find safety feedback on Betrixaban long term.
Betrixaban is generating a lot of interest in the field, and is receiving attention because of its safety and long-term potential. How all this will work out for Otsuka will determine whether the Varrocos can bring back patient care. If everything goes according to Otsuka’s plan, that would be fantastic news for patients.