drug repurposing Flashcards
name 3 drugs that were repurposed
sildenafil - viagra initially developed for treatment of angina in 1990, later in 1998 was marketed as treatment ED, recently rebranded as Revatio for treatment of pulmonary arterial hypertension
thalidomide - originally licensed in 1957 as sedative, later marketed as OTC med for morning sickness - was withdrawn in 1961 - as it was found to cause severe birth defects, recently repurposed for treatment of erythema nodosum (FDA 1998) and mutliple myeloma (FDA approved 2006)
finasteride - originally licensed in 1992 as proscar for treatment of benign prostate hyperplasia, 2nd licensed granted in 1997 - rebranded to propecia - treatment of hair loss in men
what are the problems associated with new drug development?
escalating costs
- around 1.15 billion dollars on all R&D before new med is licensed
decreasing ROI
- for every 25000 compounds - average of 25 go through clinical testing, and 5 become licensed
long development time
- around 12 years for drug to reach quality, safety, efficacy laid down by legislation
risk of post-marketing failure
risk of limited clinical utility
traditional drug discovery vs drug re-purposing
drug repurposing builds on previous R&D - allows faster development + saves substantial costs associated with previous attrition
de novo drug discovery and development process:
- target discovery
- drug discovery & screening
- lead optimisation
- pre clinical studies
- clinical trials
- licensing
10-17 years
drug repurposing
- compound identification
- compound acquisition
- pre clinical
- clinical
- licensing
3 - 12 years
benefits of drug repurposing
saves long development time and costs
- repurposing of an existing licensed med for a new therapeutic indication - can directly go to phase II trials - saves 3-5 years
reduces risk
- risk of attrition eliminated
- less risk for financial investors
- less risk for patients - as adverse effects are known
problems with drug repurposing
repurposing off patent drugs for a new therapeutic indication - may offer little financial incentive if no new patent is available -
commercial benefits depend on patent issues
need for reformulation of repurposed drugs comprises time and cost
complications in prescribing - dosing, frequency strength may be diff - may cause safety issues
without patent - no market exclusivity - limited return on investment and may face competition from generics and off label use of existing drugs
compare patents vs trade secrets
process patents:
- provide 20 year monopoly protection
- requires process to be new, inventive and have industrial application
- process must be published at end of term for 3rd parties to use
- products are protected by patents
trade secrets:
- protection as long as information is kept secret
- doesn’t require fees or formalities
- competitors never find out
- vulnerable to theft or accidental disclosure
what are circumstances in which patents work well - give examples
when product can be reverse engineered to find out process
when secrecy is hard to maintain
when enforcement can keep competitors at bay
when deterrent is useful
when licensing fees are attractive
examples of process patents - chemical synthesis methods, methods for formulation manufacture, process of improving yield, reducing impurities, processes for reducing time, energy and cost
circumstances in which trade secrets work well - give examples
when product is difficult to make
reverse engineering is impossible
info is complex
access is limited to small no of individuals
technology is not evident to human eye
examples - recipes, manufacturing techniques, blueprints, databases, customer lists
