We can extend the Quick-Kill model to estimate development efficiency - the number of successful compounds in the portfolio for a given development time period, T, and a given amount of development resource. Development capability can be expressed as the number of new molecular entities (NMEs) that can be processed in parallel - the number of “pipes” , n, in the development pipeline.
Once again, let the number of compounds to be screened be N and the proportion of “good” compounds be p. Let the time taken to develop a “good” compound be tsuccess and the time taken to kill a “bad” compound be tkill. Then the rate at which “good” compounds are brought to market is given by the number of “good” compounds discovered divided by the time taken to discover them. Without simplification this rate is given by:
Np(1-pfn) / (Np(1-pfn)tsuccess + N(1-p)tkill + Np(pfn)tkill )
To calculate the number of good compounds in the portfolio we simply multiply this figure by the number of “pipes”, n, and the period of interest, T.
nTNp(1-pfn) / (Np(1-pfn)tsuccess + N(1-p)tkill + Np(pfn)tkill )
In the Table above Pipeline Performance is expressed as the number of marketable products in the portfolio after 20 years for a Right First Time strategy and a Quick-Kill strategy with various false-negative rates. In the 20 year period the Right First Time strategy delivers 15.4 molecules. A fast fail strategy, with an early decision after just one year, delivers more than 21 molecules in the same period.
© Dennis Lendrem, 2011