- A. Menarini Farmaceutica Internazionale SRL
- AbbVie Ltd
- Accord Healthcare Limited
- Accord-UK Ltd
- Advanced Accelerator Applications
- ADVANZ Pharma
- Aerona Clinical Limited
- AGB-Pharma AB
- AGEPHA Pharma s.r.o.
- Aguettant Ltd
- Aimmune Therapeutics UK Limited
- AJ Vaccines A/S
- Akcea Therapeutics UK Ltd
- Alan Pharmaceuticals
- Albireo Pharma
- Alcon Eye Care UK Limited
- Alexion Pharma UK Ltd
- Alimera Sciences Limited
- ALK-Abello Ltd
- Allen & Hanburys Ltd
- Allergy Therapeutics
- Alliance Pharmaceuticals
- Almirall Limited
- Alnylam UK Ltd
- Alturix Limited
- Amarin Pharmaceuticals Ireland Limited
- Amarox Limited
- Amgen Ltd
- Amicus Therapeutics UK Ltd
- AMRING SARL
- Amryt Pharmaceuticals DAC
- Aristo Pharma Limited
- Arvelle Therapeutics UK
- AS Kalceks
- Aspen
- Aspire Pharma Ltd
- Astellas Pharma Ltd
- AstraZeneca UK Limited
- Atnahs Pharma UK Ltd
- Aurobindo Pharma - Milpharm Ltd.