OBJECTIVES: In the drug development process the priorities of the stakeholders (manufacturers, payers, regulators, patients, physicians) often do not align, and at times are in conflict, e.g. in the US consumers aren’t concerned about cost, but private payers are.  With cost as a significant driver to multiple decision makers, we explore monocolonal antibodies (mAb) as a drug class and the handling of their approvals and authorizations by the US and UK key bodies. METHODS: The following sources were summarized for mAbs approved in the past 10 years: the regulatory approval decision in the United States and the United Kingdom; the payer coverage decision, if applicable and available; relevant patient advocacy groups’ statements; and statements on behalf of medical organizations. Discrepancies between initial regulatory decisions and the statements of the other stakeholders were highlighted. RESULTS: These sources show the use of clinical data to advocate differing stakeholders' views.  In the case of natalizumab, patient advocacy groups and regulators disagreed on whether the risks outweighed the drug benefits. In judging the value of bevacizumab for breast cancer patients, regulators and payers are still at odds.  Furthermore, the debate between the payers and the manufacturer on the use of off-label bevacizumab seems to hinge on the clinical results from the US National Eye Institute. CONCLUSIONS: Although physicians continue to play a critical role in determining drug use once a product is approved, other stakeholders (e.g. patients and independent researchers) are increasing their sway in the market.  Given the discrepancies between the decisions of the regulators and the payers, drug manufacturers are obliged to demonstrate a product’s value to patients and payers, as well as to show that it is safe and efficacious to regulators.  The incorporation of the payers’ viewpoint in the development process will ease the gap between stakeholders.