Biotech rNPV approach question

Hey guys. I am doing a valuation of a young growth biotech firm. My method is the risk adjusted probability based NPV in which I analyze the pipeline and potential marketable products to ascertain a firm value. So far I have had no problem in individually analyzing the products and estimating future product revenue. However, I am now struggling to incorporate collaborative R&D revenue, the non dilutive financing often used by young biotech firms, and grant revenue. I do not have access to the precise nature of the agreements and licensing deals so am unsure how to predict the trend of this revenue accumulation. My solution is to get the values and evenly spread them out over the life of the product as it reaches milestones and collects the revenue. However, the time value of money may under or over value this portion of the revenue as in reality it may be recognized earlier or later. This will have a significant impact on firm value since it is a growth firm which is not making product based revenue until 2018. Furthermore, the product based revenues are probability adjusted based on the phase of clinical trials they are in and the nature of the disease/need they are trying to treat. Hence, for the next 4 years, the main driver of value is the milestone revenue, and payments made for the covering of R&D costs. Are there any established professionals in healthcare banking who could shed any light on how to tackle this issue in a less crude manner? Or anyone with some innovative ideas? Thanks for the help.