Changes in Senior Management Personnel (SMP) of the Company - Disclosure under Regulation 30 of SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015

Corporate Office: Registered Office: Star 1, Opp IIM Bangalore, Bilekahalli, Cyber One, Unit No. 902, Sector 30A, Bannergha(cid:425)a Road, Bengaluru – 560076, Plot No - 4 & 6, Vashi, India Navi Mumbai - 400703, India T: +91 80 6784 0738 T: +91 22 2789 2924 F: +91 22 2789 2942 Date: July 27, 2026 BSE Limited National Stock Exchange of India Limited Phiroze Jeejeebhoy Towers, Exchange Plaza, C-1, Block G, Dalal Street Bandra Kurla Complex, Mumbai- 400001 Bandra (E) Mumbai – 400051 Scrip Code: 544292 Symbol: ONESOURCE Dear Sir/ Madam, Subject: Changes in Senior Management Personnel (SMP) of the Company – Disclosure under Regulation 30 of SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015 (“Listing Regulations”) We refer to the intimation dated July 24, 2026, wherein we had intimated changes in SMP as under, and as per attached disclosure (Annexure 1 and Annexure 2 respectively). Designated as SMP: Preeti Kalra (Head - Human Resources) has been designated as a SMP of the Company effective July 24, 2026. Cessation as SMP: Ravi Kumar (Global Head – Injectables/ Head of Corporate Strategy, Portfolio & SPO), Senior Management Personnel (SMP) of the Company has resigned from his position effective July 24, 2026. Further to the above, as required under Part A (A) (7C) of Schedule III to the Listing Regulations, we have attached the resignation letter as received from Ravi Kumar as Annexure 3, for your records. This is for your information and records. For and on behalf of OneSource Specialty Pharma Limited Trisha A Company Secretary and Compliance Officer Membership Number: A47635 OneSource Specialty Pharma Limited Formerly Stelis Biopharma Limited info@onesourcecdmo.com | www.onesourcecdmo.com CIN: L74140MH2007PLC432497 Corporate Office: Registered Office: Star 1, Opp IIM Bangalore, Bilekahalli, Cyber One, Unit No. 902, Sector 30A, Bannergha(cid:425)a Road, Bengaluru – 560076, Plot No - 4 & 6, Vashi, India Navi Mumbai - 400703, India T: +91 80 6784 0738 T: +91 22 2789 2924 F: +91 22 2789 2942 Annexure – 1 Disclosure pursuant to Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015, read with Circular No. HO/49/14/14(7)2025-CFDPOD2/I/3762/2026 dated January 30, 2026 Designation of Preeti Kalra as SMP Sl. Particulars Description 1. Reason for change viz. appointment, Designated as Senior Management Personnel re-appointment, resignation, removal, death or otherwise. 2. Date of cessation NA 3. Brief profile in case of appointment  HR leader with 25+ years of experience across Biopharma, Global Development (Not-for-Profit), Public Services, Insurance, GCC and IT  Extensive leadership experience with organizations including Stelis Biopharma, Biocon Biologics, Bill & Melinda Gates Foundation, Serco and Ernst & Young  Expertise in business partnering, talent management, leadership development, organizational transformation, culture, organization effectiveness and change management  Proven track record of enabling business growth by building high-performing teams, strengthening leadership capability and driving organizational effectiveness across Asia-Pacific, Middle East, Africa, Europe and North America 4. Disclosure of relationship between Not Applicable directors (in case of appointment of director) OneSource Specialty Pharma Limited Formerly Stelis Biopharma Limited info@onesourcecdmo.com | www.onesourcecdmo.com CIN: L74140MH2007PLC432497 Corporate Office: Registered Office: Star 1, Opp IIM Bangalore, Bilekahalli, Cyber One, Unit No. 902, Sector 30A, Bannergha(cid:425)a Road, Bengaluru – 560076, Plot No - 4 & 6, Vashi, India Navi Mumbai - 400703, India T: +91 80 6784 0738 T: +91 22 2789 2924 F: +91 22 2789 2942 Annexure – 2 Disclosure pursuant to Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015, read with Circular No. HO/49/14/14(7)2025-CFDPOD2/I/3762/2026 dated January 30, 2026 Cessation as SMP –Ravi Kumar Sl. Particulars Description 1. Reason for change viz. appointment, re- Ceased to be a Senior Management Personnel consequent to appointment, resignation, removal, death or resignation otherwise. 2. Date of cessation Close of business hours, July 24, 2026 3. Brief profile in case of appointment Not applicable 4. Disclosure of relationship between directors Not Applicable (in case of appointment of director) OneSource Specialty Pharma Limited Formerly Stelis Biopharma Limited info@onesourcecdmo.com | www.onesourcecdmo.com CIN: L74140MH2007PLC432497 Annexure 3 July 24, 2026 The Managing Director OneSource Specialty Pharma Limited Dear Sir, Sub: Resignation from the position of Global Head – Injectables/ Head of Corporate Strategy, Portfolio & SPO - OneSource Specialty Pharma Limited I hereby tender my resignation from the position of Global Head – Injectables/ Head of Corporate Strategy, Portfolio & SPO at OneSource Specialty Pharma Limited due personal reasons with effect from the close of business hours on July 24, 2026. I take this opportunity to thank the Management of the Company for their support during my association with the Company. Warm regards Ravi Kumar