Looking Beyond Overall Survival
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The pharma industry is in constant evolution. Nowhere is this more pronounced than in the fight against cancer. Roughly 14 million people are diagnosed, and more than 8 million succumb to the disease each year.
Our understanding of how cancer develops and thrives has grown. In the past five years alone, 70 new oncology therapies have launched, while countless others are being developed. As the oncology research and treatment landscape evolves, so too must our approach to drug development and trial design.
In oncology clinical trials, overall survival (OS) has long been the “gold standard” of measuring the efficacy of a new treatment. While OS remains valuable in understanding a drug's efficacy, it has become a more complex endpoint. With patients having more options and living longer, demonstrating an OS advantage for one therapy versus another in a controlled clinical trial is not always possible, or can take a long time.
Thanks in large part to the knowledge we've accumulated on tumor biology and the accelerated approval pathways offered by regulatory bodies such as the FDA, we no longer have to take a linear approach to development. Rather, we can quickly move on promising data, even in its early phases.
Progression-free survival and metastasis-free survival (MFS), among others, are becoming more widely recognized as important alternative endpoints that can also form the basis for regulatory approval. The use of event-free survival endpoints such as these has increased significantly, with 43% of recent FDA approvals using such an endpoint between 2006 and 2011, compared to only 13% in the 1990s.
The realities of the disease must inform how we approach trial endpoints.
For example, take prostate cancer. For many men, early screening and slow progression means their disease can be effectively treated or may only require active surveillance. But roughly 20% will progress to advanced stages within five years.
Patients have different treatment goals and therefore require distinct treatment plans. Trials must be designed with this in mind and measure not only how patients can live longer, but also how they can live better. MFS and symptomatic skeletal event-free survival (SSE-FS — survival time without symptomatic events such as fractures, caused by metastasis to the bone) are meaningful clinical measures.
While improved survival will remain the ultimate treatment goal, we might miss something important if we rely only on overall survival to measure the effectiveness of a medicine.
Volker Wagner is VP of clinical development in oncology at Bayer