edit this article for a sophisticated audience. Accelerated approval has provided massive benefits to cancer patients, contributing over 260,000 additional life years from 2006 to 2021, according to a study published in the Journal of the National Comprehensive Cancer Network. 
Estimating the benefits from accelerated approval could help protect the pathway against academic critics, and counter misleading research that has led some medical journals and news organizations to inaccurately report that a large proportion of accelerated approval cancer drugs did not extend overall survival. 
The analysis published in JNCCN modeled the increase in survival during the interval between accelerated and regular approvals for 130 oncology treatments. It was conducted by researchers at Evidera, a consultancy owned by Pharmaceutical Product Development, LLC, a CRO, and the Janssen unit of Johnson & Johnson. 
While the paper makes a powerful case for accelerated approval, it underestimates the impact of the pathway because it doesn’t account for the ways accelerated approval has derisked investment in cancer drugs. By reducing uncertainty, approvals based on non-clinical and intermediate endpoints have incentivized investments in drugs that otherwise may not have been developed.  

Massive impact
More than half of the additional life years the Evidera and J&J researchers attributed to accelerated approval came from a single drug. 
Perjeta pertuzumab from the Genentech unit of Roche (SIX:ROG; OTCQX:RHHBY) was responsible for 155,000 additional life years between June 2012, when it received accelerated approval for use in combination with Herceptin trastuzumab and docetaxel chemotherapy to treat HER2-positive metastatic breast cancer and December 2017 when it received regular approval, according to the study. 
Ibrance palbociclib from Pfizer Inc. (NYSE:PFE) contributed over 73,000 additional life years during the interval between its accelerated and regular approvals. 
The model may underestimate additional life years for slowly progressing cancers. For example, its attribution of 11,800 additional life years to Gleevec imatinib from Novartis AG (SIX:NOVN; NYSE:NVS) for chronic myeloid leukemia (CML) during the four years between accelerated and regular approval is almost certainly an undercount. 

Creating opportunities
More fundamentally, the study underestimates lives extended by accelerated approval because it does not consider the probability that some drugs would never have been developed in the absence of the pathway. 
To understand why accelerated approval creates opportunities, it is necessary to understand that the term a misnomer because its principal benefit isn’t speeding approvals. 
Rather, it is valuable for two reasons. It makes it possible to develop drugs based on endpoints other than survival or a definitive measure of clinical benefit, and the requirement for post-market studies to confirm benefit allows FDA to take risks. Approvals can be modified or withdrawn if drugs do not live up to expectations.  
Accelerated approval was created in response to the AIDS crisis and from the start it brought drugs to patients that wouldn’t have been developed if they had to meet regular approval standards. The use of surrogate endpoints allowed drug companies to avoid lengthy studies powered to demonstrate survival benefits, and to rapidly iterate better drugs. 
In the time it would have taken to study the effect of a single drug on survival, companies were able to get accelerated approval for multiple drugs with different mechanisms of action, to test them in combinations, and to come up with highly effective regimens. Millions of lives were saved. 
Adopting the pathway to cancer has required a great deal of creativity. Defining non-clinical or interim endpoints that are reasonably likely to predict clinical benefit for many different kinds of cancer and crafting approaches to confirming benefits is complex and often contentious. 
As the Evidera and J&J research demonstrates, the work has paid off. 
Like the AIDS experience, the possibility of receiving accelerated approval has made it scientifically and financially viable to develop and iterate on drugs to treat deadly, slowly progressing cancers. 
This may be why there have been a large number of accelerated approvals for hematological cancers. 
In addition to iterative development of drugs to treat a specific kind of cancer, accelerated approval has facilitated iterative development of drugs to treat different cancers. As BioCentury has described, the poster child for this phenomenon is Keytruda pembrolizumab from Merck & Co. Inc. (NYSE:MRK).