Redx announces new research collaboration with Jazz Pharmaceuticals to discover and develop two targeted cancer therapies

Redx will lead discovery and preclinical development activities on two cancer targets

Redx to receive $10 million upfront and $10 million in year 2 with up to a further $400 million in milestone payments, plus tiered royalties

Research collaboration recognises Redx's expertise in oncology drug design following previous sale of Redx's pan-RAF inhibitor programme to Jazz in July 2019

Alderley Park, 9 September 2020 Redx Pharma plc(AIM: REDX), the drug discovery and development company focused on cancer and fibrosis, is pleased to announce that it has signed a new research collaboration agreement with Jazz Pharmaceuticals plc (Nasdaq: JAZZ; "Jazz") to discover and develop drug candidates for two cancer targets on the Ras/Raf/MAP kinase (MAPK) pathway. Redx will be responsible for research and preclinical development activities up to Investigational New Drug (IND) submission.

Under the terms of the agreement, Jazz will pay Redx an upfront payment of $10 million followed by another $10 million in year two provided research work is continuing. Following delivery of an IND-ready molecule, Redx will be eligible to receive up to a further $200 million from Jazz in development, regulatory and commercial milestone payments1 for each programme. The first milestone is payable upon successful IND submission and all subsequent milestones are contingent on successful completion of the relevant stages of development.

In addition, for both programmes, Redx is eligible for tiered royalties in mid-single digit percentages, based on any future net sales. Jazz will own all intellectual property as it is generated, and following a successful IND submission, will be responsible for further development, manufacturing, regulatory activities and commercialisation.

This research collaboration follows the previously announced sale of Redx's preclinical pan-RAF inhibitor programme to Jazz for the potential treatment of RAF and RAS mutant tumours in July 2019. The pan-RAF collaboration between the companies, following on from that sale, has been progressing well. This new agreement with Jazz builds on the existing collaboration and further validates Redx's strength in medicinal chemistry and drug design, as well as its proven capability as a successful research partner.

In addition to pursuing this collaboration, Redx continues to execute its strategy in progressing its lead oncology and fibrosis programmes, including oral porcupine inhibitor RXC004, targeting Wnt-driven tumours in an ongoing clinical trial, and oral ROCK2 inhibitor RXC007, targeting fibrosis, planned to enter the clinic in 2021.

Lisa Anson, Chief Executive Officer of Redx Pharma, commented: "We are extremely pleased to announce this new collaboration with Jazz, which expands on our already strong working relationship, built through a year of collaboration on the pan-RAF inhibitor programme. This new agreement reinforces Redx's strong position as a successful research partner and its expertise in medicinal chemistry and drug design. We look forward to collaborating with Jazz on new targeted therapies for patients who need them."

Robert Iannone, M.D., M.S.C.E., executive vice president, research and development of Jazz Pharmaceuticals added: "We are excited to collaborate with Redx on two oncology programs in the Ras/Raf/MAP kinase pathway. Redx has established itself as a strong partner for Jazz, given the continued momentum in our existing collaboration on pan-RAF, and we look forward to this new collaboration and access to Redx's small molecule discovery capabilities. We are strategically targeting this cancer pathway with multiple experimental approaches while further strengthening our targeted oncology pipeline. These programs in the Ras/Raf/MAP kinase pathway are highly complementary to our growing R&D portfolio of innovative and targeted oncology therapies."

For further information, please contact:

Redx Pharma Plc

T: +44 1625 469 918

Iain Ross, Chairman

Lisa Anson, Chief Executive

SPARK Advisory Partners Limited (Nominated Adviser)

T: +44 203 368 3550

Matt Davis/Andrew Emmott

WG Partners LLP (Joint Broker)

T: +44 20 3705 9330

Claes Spång/ Chris Lee/ David Wilson

FTI Consulting

T: +44 20 3727 1000

Simon Conway/Ciara Martin

About Redx Pharma Plc

Redx is a UK based biotechnology company whose shares are traded on AIM (AIM:REDX). Redx's vision is to become a leading biotech focused on the development of novel precision medicines that have the potential to transform treatment in oncology and fibrotic diseases.

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About Jazz Pharmaceuticals plc

Jazz Pharmaceuticals plc (Nasdaq: JAZZ) is a global biopharmaceutical company dedicated to developing life-changing medicines for people with serious diseases - often with limited or no options. Jazz has a diverse portfolio of marketed medicines and novel product candidates, from early- to late-stage development, in key therapeutic areas. Jazz's focus is in neuroscience, including sleep medicine and movement disorders, and in oncology, including hematologic and solid tumors. Jazz actively explores new options for patients including novel compounds, small molecule advancements, biologics and innovative delivery technologies. Jazz is headquartered in Dublin, Ireland and has employees around the globe, serving patients in more than 90 countries. For more information, please visit www.jazzpharmaceuticals.com and follow @JazzPharma on Twitter.

Jazz Pharmaceuticals plc "Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995

This press release contains forward-looking statements, including, but not limited to, statements related to the potential successful submission of an investigational new drug application and future development, manufacturing, regulatory and commercialization activities; potential future payments by Jazz Pharmaceuticals to Redx for development, regulatory and commercial milestones as well as tiered royalties based on future net sales; and other statements that are not historical facts. These forward-looking statements are based on Jazz Pharmaceuticals' current plans, objectives, estimates, expectations and intentions and inherently involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks and uncertainties associated with: Jazz Pharmaceuticals' ability to achieve the expected benefits (commercial or otherwise) from the research collaboration agreement; pharmaceutical product development and clinical success thereof; the regulatory approval process; effectively commercializing any product candidates; and other risks and uncertainties affecting Jazz Pharmaceuticals, including those described from time to time under the caption "Risk Factors" and elsewhere in Jazz Pharmaceuticals plc's Securities and Exchange Commission filings and reports (Commission File No. 001-33500), including Jazz Pharmaceuticals' Quarterly Report on Form 10-Q for the quarter ended June 30, 2020 and future filings and reports by Jazz Pharmaceuticals. Other risks and uncertainties of which Jazz Pharmaceuticals is not currently aware may also affect Jazz Pharmaceuticals' forward-looking statements and may cause actual results and the timing of events to differ materially from those anticipated. The forward-looking statements herein are made only as of the date hereof or as of the dates indicated in the forward-looking statements, even if they are subsequently made available by Jazz Pharmaceuticals on its website or otherwise. Jazz Pharmaceuticals undertakes no obligation to update or supplement any forward-looking statements to reflect actual results, new information, future events, changes in its expectations or other circumstances that exist after the date as of which the forward-looking statements were made.

[1] Redx works alongside major global pharmaceutical companies to utilise its intellectual property and expertise to develop drugs and treatments targeted at oncology and fibrosis. When working on development programmes Redx will typically receive upfront payments from global pharmaceutical companies and also an agreed quantum of milestone achievement dependent payments which are paid over the life of the programme. A typical programme may be as short as two years or in excess of ten years dependent on circumstance. The actual length of a development programme cannot be determined with accuracy at its commencement and will be dependent on a large number of factors, many of which will be outside the control of Redx.