The Food & Drug Administration’s (FDA) Aug. 14, 2014, approval of Roche’s biologic agent, Avastin (bevacizumab), for use with chemotherapy in treating late-stage cervical cancer, confirms that the drug effectively fights multiple tumor types. Avastin was approved for treating colorectal cancer when it was first introduced to the U. S. pharmaceutical marketplace in 2004. Since then it has been approved for use in non-small cell lung cancer, glioblastoma and kidney cancer, and is slated to be approved for treating ovarian cancer later this year.
Avastin is the first biologic agent approved for use in combination with chemotherapy. Biologic agents are generally made from human or animal materials and are distinct from the chemically synthetic molecules most often thought of as drugs. Avastin is an antibody that inhibits the formation of blood vessels that supply tumors, in essence killing the tumors by choking off their blood supply. Bevacizumab gave rise to a whole new class of drugs, referred to as antiangiogenesis drugs, because it was the first pharmaceutical product to work in this manner of inhibiting blood vessel formation.
According to Roche, the combination of chemotherapy and antiangiogenesis creates a therapeutic option that helps women with aggressive, late-stage cervical cancer live longer than they would with chemotherapy alone. Therapy options are important for patients with cervical cancer because less than 40 percent of women with advanced cervical cancer have a life expectancy of more than five years from the time of diagnosis. The aggressive nature of cervical cancer, and the ease with which it can be prevented, is why health professionals encourage annual screenings, including Pap test and human papilloma virus (HPV) testing beginning at age 21. Preventive HPV vaccines are also available for women between the ages of nine and 26.
While this new approval provides an additional treatment option for late-stage cervical cancer patients, the side effects of Avastin can be severe. Significant side effects include significantly raised blood pressure and blood sugar which can exacerbate existing conditions. Depending on the stage of advancement of the disease and the aggressiveness of tumor growth, the side effects from taking Avastin may seem minimal. However, Avastin’s breast cancer approval application was denied by the FDA in 2011 because clinical trials failed to show that breast cancer patients taking Avastin lived longer. Doctors may still prescribe Avastin for breast cancer as an off-label use of the product, but insurance will not pay for off-label uses.
Biosimilars are an emerging force within the pharmaceutical industry. A U. S. drug patent lasts for 20 years, and Avastin’s U.S. patent is set to expire in 2019. Sales of most chemically based drugs tend to plummet after their patents expire and generic versions of the same chemical molecule become available. Because Avastin is a biologic agent, it will not compete with generic versions of itself after its patent expires, but will, instead, compete with biosimilars, which are biological products that are can be shown to be highly similar to bevacizumab, the original U. S.-licensed reference compound. The biosimilar products may have minor differences in components that are clinically inactive, but will have no meaningful clinical differences in terms of safety, purity or potency. The Patient Protection and Affordable Care Act (Affordable Care Act) of 2010 created an abbreviated licensure pathway for biosimilars that can be shown with data to be highly similar to an FDA-licensed biological product.
Avastin has been a top-selling drug for Roche since its U. S. debut in 2004 and routinely tops lists of top-selling drugs industry-wide. Approval for these additional indications allows for promotion/exclusivity within these markets to prolong the payout for the drug and alleviate competition from biosimilars. Official FDA approval for multiple tumor types including cervical cancer and ovarian cancer will help Avastin fight other, biosimilar, biologic agents once they are approved for market. Currently, no biosimilar agents have entered the FDA approval process, but companies such as Amgen and Fujifilm Kyowa Kirin Biologics have announced their intentions to do so.
According to testimony on supplemental indications for approved prescription drugs delivered by FDA Deputy Commissioner for Operations Michael Friedman to the House Committee on Government Reform and Oversight in 1996, public confidence in pharmaceutical therapy has been built on the recognized rigor of FDA’s approval process. That message still holds true today. The FDA is careful to state on its Web site that it “will require licensed biosimilar and interchangeable biological products to meet the Agency’s exacting standards of safety and efficacy.” Whether it is old, or new, or biosimilar, a biologic agent that fights cervical cancer and other, multiple, tumor types is a valuable commodity.
By Lane Therrell
FDA (FDA approves Avastin to treat patients with aggressive and late-stage cervical cancer)
FDA (FDA 101: Regulating Biological Products)
FDA (Information for Consumers (Biosimilars))
National Cancer Institute
Fierce Pharma (Top 10 best-selling cancer drugs of 2013)
Fierce Pharma (Roche’s Avastin nabs quick FDA nod for cervical cancer use)
Fierce Pharma (FDA fast-tracks Roche’s Avastin for tough-to-treat ovarian cancer)
Genetic Engineering and Biotechnology News