FirstWord Lists: The best selling drugs of all time - lifetime sales analysis

Since 1996, the pharmaceutical industry has launched 18 products that have subsequently generated peak annual sales of $5 billion or above. FirstWord has previously analysed these 'titan' drugs here and here. A frequent request, however, has been to assess the lifetime revenues of these products.

Based on historical company reported sales data, through to 2012, these 18 drugs have generated combined lifetime revenues worth a staggering $942 billion.

Assessing the industry's biggest ever products by lifetime sales, rather than peak annual performance, further confirms the status of Pfizer's Lipitor as the most commercially successful drug of all time. Over the course of its lifetime, Lipitor has generated global sales of $141 billion – nearly double that of its closest competitor in the list, Bristol-Myers Squibb and Sanofi's Plavix.

Clearly this analysis is distorted to some extent by the earlier launch date of Lipitor (in 1996). However, if we look at cumulative sales during the first 10 years of availability, Lipitor still comes out on top (revenues of $73 billion) albeit by a significantly slimmer margin; the more recent launches of Humira (2003) and Januvia (2006) are positioned in second and third place with cumulative 10-year sales totals of $64 billion and $50 billion, respectively (although it is worth noting that post-2012 revenues are based on consensus forecasts sourced from Bloomberg).

Interestingly, based on cumulative revenue performance for the subsequent five years of availability (i.e. years 11 to 15 on the market), Humira is forecast to outperform Lipitor with global revenues of $69 billion versus $63 billion. Furthermore, Humira is forecast to record higher cumulative sales during this subsequent five-year period, compared to its first 10 years of availability. Of the 18 products on the list, seven share this characteristic – six of which (Remicade, Enbrel, Lantus, Herceptin, Rituxan and Humira) are biologics.

A propensity for generating greater cumulative sales during this 'secondary' period of each product's lifecycle does not only reflect a lack of exposure to patent expiry or a meaningful decline in sales due to loss of exclusivity for a competing drug in the same class, but also a more pronounced correlation for biologics towards an 'S curve' uptake model.

Initial revenue uptake of these products has typically been slower, not only as the biologics in question have generally addressed speciality-care rather than primary-care conditions, but because there has been a steadier adoption of new technology by physicians. This trend is somewhat illustrated by the respective performances of the anti-TNF products Remicade (approved 1998) and Humira (2003) – cumulative Remicade sales are notably 'back-loaded' compared to those for Humira, which was able to ride on the wave of success for anti-TNFs that occurred before its launch.

Other factors have also played a key role in driving this trend. Most of the biologics in the list have seen revenues expand as a result of subsequent indication approval, while usage of many – particularly in oncology – has driven market expansion by virtue of improved survival rates. The best example of this trend is probably for Novartis' Gleevec (ironically a small molecule and positioned just outside this list with sales of $4.7 billion in 2012), which has effectively transformed chronic myeloid leukaemia (CML) from a death sentence to a chronic condition since its launch in 2001.

The upshot is that not only have biologics become an integral element of the 'titan blockbuster' landscape, but that Lipitor is in danger of being overthrown as the most commercially successful drug of all time. Pfizer's statin may have generated an eye-watering $136 billion during its first 15 years of availability (1996-2011) – more than any other product – but subsequent performance, from 2012 onwards, has been characterised by a steep erosion in sales due to patent exclusivity.

Based on consensus forecasts, AbbVie’s Humira is expected to generate global sales of $134 billion during its first 15 years of availability (at which point analysts expect the drug to have eclipsed Lipitor in terms of peak annual performance, with sales forecast to rise above $14 billion by 2017). With Humira's biologic status set to insulate the franchise from a steep generic-driven decline, it is likely that by 2020, AbbVie's product will have broken more sales records.

To read more List articles, click here.