Barriers to innovation in human rabies prophylaxis and treatment: A causal analysis of insights from key opinion leaders and literature.

Rabies is an essentially 100% fatal, zoonotic disease, caused by Lyssaviruses. Currently, the disease is vaccine-preventable with pre- and post-exposure prophylaxis (PrEP and PEP). Still, rabies virus is estimated to cause up to 60,000 human deaths annually, of which the vast majority occurs in rural Asia and Africa, due to the inaccessibility of prophylaxis and non-existence of treatment. Despite these unmet clinical needs, rabies control mainly focuses on the sylvatic reservoir and drug innovation receives relatively little attention compared to other neglected tropical diseases (NTDs). As such, the lag of innovation in human rabies prophylaxis and treatment cannot be explained by limited return on investment alone. Strategies countering rabies-specific innovation barriers are important for the acceleration of innovation in human rabies prophylaxis and treatment. Barriers throughout society, science, business development and market domains were identified through literature review and 23 semi-structured interviews with key opinion leaders worldwide. A subsequent root cause analysis revealed causal relations between innovation barriers and a limited set of root causes. Finally, prioritization by experts indicated their relative importance. Root causes, which are fundamental to barriers, were aggregated into four types: market and commercial, stakeholder collaboration, public health and awareness, and disease trajectory. These were found in all domains of the innovation process and thus are relevant for all stakeholders. This study identifies barriers that were not previously described in this specific context, for example the competition for funding between medical and veterinary approaches. The results stress the existence of barriers beyond the limited return on investment and thereby explain why innovation in human rabies medication is lagging behind NTDs with a lower burden of disease. A re-orientation on the full spectrum of barriers that hinder innovation in rabies prophylaxis and treatment is necessary to meet unmet societal and medical needs.