Half Year Trading Update

• Continued commercial, financial and operational momentum as OXB executes on its multi-vector, multi-site strategy
• H1 2025 revenues of £70-73 million, an increase of 38%-44% vs. £51 million at H1 2024
• Commercial momentum accelerating, with £149 million new orders1 signed during H1 2025, more than double the £56 million orders signed during H1 2024
• Full year 2025 guidance (CC2) reiterated: £160-170 million in revenues and low single digit operating EBITDA3 profitability

o Over £165 million of 2025 revenues contracted vs. £103 million at H1 2024

• Strong order book reinforcing confidence in both full year 2025 and medium-term revenue growth

o Revenue backlog4 of £222 million at 30 June 2025

• The Company will announce its H1 2025 interim results on 23 September 2025 with a Capital Markets Day scheduled for 15 October 2025

Oxford, UK - 28 July 2025: OXB (LSE: OXB) ("the Company"), a global quality and innovation-led cell and gene therapy CDMO, today provides a trading update for the six months ended 30 June 2025.

Dr. Frank Mathias, Chief Executive Officer of OXB, commented: "With our multi-vector, multi-site model now fully in place, our strong operational and commercial progress continued in the first half of the year, reflecting both our execution capabilities and the growing trust in OXB as a leading cell and gene CDMO partner. Our order book has more than doubled year-on-year, including notable growth in late-stage programme activity, demonstrating strong demand for our services and providing long-term revenue visibility. As we expand capacity to meet this growing demand, we remain focused on operational excellence and cost discipline. With robust fundamentals in place and clear visibility into the second half of the year, we remain confident in our ability to deliver our full year guidance and achieve sustainable growth in 2025 and beyond."

Strong first half performance; full year guidance reiterated

For the six months ended 30 June 2025, OXB expects to report revenues of approximately £70-73 million, representing an increase of 38%-44% over H1 2024 revenues of £51 million. The Company reiterates full year 2025 revenue guidance of £160-170 million (on a constant currency basis). Over £165 million of 2025 revenues are covered by contracted client orders, compared to £103 million for the same period last year. This provides clear visibility for the remainder of the year (subject to revenue performance obligations), with revenues weighted to the second half, in line with prior years. Second half revenue phasing includes an increase in manufacturing activity for clients preparing for commercial launch.

With a continued focus on efficiency and a disciplined approach to cost management, the Company continues to expect low single digit Operating EBITDA profitability (on a constant currency basis) for the full year 2025. OXB's cash position remains strong with gross cash of £53.9 million as of 30 June 2025.

Late-stage lentiviral programme demand driving strong commercial momentum

The contracted value of client orders signed during the first half of 2025 totalled approximately £149 million, compared to £56 million for the six months ended 30 June 2024. This includes signed orders from clients preparing for late-stage and commercial activities, providing strong visibility for the remainder of 2025 and 2026. Revenue backlog stood at approximately £222 million as at 30 June 2025, compared to approximately £150 million as at 31 December 2024.

Demand for OXB's CDMO services remains strong, with consistent conversion across all key vector types. The alignment of operations across the UK, the US and France is increasing efficiency and agility, allowing OXB to support clients across geographies and development stage. OXB is seeing increased client demand from existing and new clients, particularly among clients looking to accelerate execution of late-stage lentiviral programmes. AAV client activity has also continued to grow in line with expectations.

Multi-vector, multi-site strategy delivering on plan

OXB's multi-vector, multi-site strategy continues to progress well, with lentiviral vector manufacturing capabilities now available across its UK, US and French sites. In June 2025, OXB completed the acquisition of the remaining 10% stake in its US subsidiary, OXB US LLC, from Q32 Bio, Inc. The site is fully integrated into OXB's global network and together with its UK and France operations, the Company is well positioned to provide global client support across all major vector types and development stages.

Reflecting continued strong client demand for OXB's services, the Company is proceeding with planned capacity management initiatives to accommodate current and expected growth. This comprises:

• an increase in GMP manufacturing capacity at OXB's UK sites, to be achieved by refitting existing suites and modifying shift cadence, to be completed by H1 2026; and
• expanding UK lab capacity for development services to support late-stage client programme activities, including increasing the use of automation.

In addition, the Company has commenced transferring its AAV vector platform to its sites in France, providing a unified global operation focused on client-centric excellence. Process development and pilot manufacturing capabilities for AAV are now available for clients in France, with transfer of GMP capabilities targeted to be completed by the first half of 2026.

Notice of Results and Capital Markets Day

OXB will report its Interim Results for the six months ended 30 June 2025 on 23 September 2025. A briefing for investors and analysts will take place at 13:00 BST / 08:00 ET at RBC Capital Markets, 100 Bishopsgate, London, EC2N 4AA.

The Company also announces it will host a Capital Markets Day on 15 October 2025. Further details, including the agenda and how to register, will be disclosed in due course.

1Contracted value of client orders represent the value of customer orders for which the customer has signed a financial commitment, whereby any changes to agreed values will be subject to either change orders, cancellation fees or the triggering of optional/contingent contractual clauses.

2CC refers to Constant Currency, which refers to the equivalent growth based on the prior year exchange rates.

3Operating EBITDA (Earnings Before Interest, Tax, Depreciation, Amortisation, Impairment, revaluation of investments and assets at fair value through profit and loss and share based payments).

4Revenue backlog represents the ordered gross value of CDMO revenues available to earn. The value of customer orders included in revenue backlog only includes the value of work for which the customer has signed a financial commitment for OXB to undertake, whereby any changes to agreed values will be subject to change orders, cancellation fees or the triggering of optional/contingent contractual clauses.