| Obstacle | Explanation |
| Need for a company to manage the development and introduction of a new product with good collaboration from the other companies | If Gilead and/or ViiV are not willing to take leadership, generic companies or other partners might take the lead. |
| Access to data on each individual agent | Gaining regulatory permission to test agents together may require ability to reference the master file for each agent. |
| Financing of new product development | The cost of developing and introducing a new product would be substantial. Neither innovator nor generic manufacturers may have motivation to invest unless they have proprietary rights. |
| Formulation development | Combining the 2 agents into a single pill would require reformulation and expertise in this area. |
| Clinical testing of new combinations | Beyond showing bioequivalence of a combination to each agent given separately, further tests may be needed. |
| Manufacturing scale-up | A new, quality-assured process would need to be developed to manufacture the new product at large scale. |
| Registration of the products in many countries | A market authorization holder of the new product(s) would be needed, responsible for regulatory filing, marketing, and pharmacovigilance of the new product. |
| Introduction of the product in country programs | Country guidelines, policies, and plans would need to be adapted, and providers would need to be trained in how to use the new product. |
Abbreviations: ARV, antiretroviral; MPP, Medicines Patent Pool; TAF, tenofovir alafenamide fumarate.
↵a Plus a third agent—either emtricitabine or lamivudine.