SIK1 x SIK3 x SIK2

Galapagos has cut anti-inflammatory drug candidate GLPG4399 following the completion of an early-stage healthy volunteer trial, according to its 2022 annual report released Thursday afternoon. GLPG4399 was a SIK3 inhibitor, one in a line of such salt-inducible kinase (SIK) inhibitors that Galapagos has been trying to develop for inflammatory diseases like rheumatoid arthritis and ulcerative colitis. Originally, the biotech had been planning to move the drug forward in a study with rheumatoid arthritis patients in the middle of this year, but now it’s halting the program and going back to search for new SIK inhibitors. “Medicinal chemistry activities to identify SIK inhibitors with improved pharmacology continues,” Galapagos noted briefly in its press release. GLPG4399 was the third SIK inhibitor Galapagos brought out of the clinic — all part of a franchise Galapagos dubbed Toledo. The first candidate, GLPG3312, similarly only made it through healthy volunteer studies before Galapagos scrapped it. The second, GLPG3970, disappointed in Phase II trials in ulcerative colitis and rheumatoid arthritis, and though it showed some signs of efficacy in psoriasis, Galapagos opted to toss that candidate as well. The small pipeline prune comes after Galapagos laid off 200 staffers and discontinued work on its fibrosis and kidney disease programs, cuts that followed a long string of setbacks at the biotech. In December, Galapagos also announced that its chief business officer André Hoekema and chief medical officer Walid Abi-Saab are retiring, though the latter is remaining with the company until the end of May. Galapagos shares $GLPG fell almost 8% after the markets opened Friday. The biotech did not immediately return request for comment.

Webcast presentation tomorrow, 6 August 2021, at 14.00 CET / 8 AM ET, , +32 2 793 38 47, code 8245817 Mechelen, Belgium; 5 August 2021, 22.01 CET; regulated information – Galapagos NV (Euronext & NASDAQ: GLPG) is pleased to report progress on earlier-stage programs as well as its commercial launch of filgotinib in Europe. Following recent setbacks, the company is moving forward with its revised strategy and operational restructuring announced in May. The unaudited H1 financial and operational results are further detailed in the H1 2021 report available on the website, . “Multiple assets are moving through clinical development, and we recently reported positive topline data on our TYK2 compound GLPG3667. In a Phase 1b trial in psoriasis (Pso), clinical activity was observed at 4 weeks, combined with an encouraging safety and tolerability profile. We currently are running an extended dose escalation study in healthy volunteers, and plan to progress GLPG3667 to a Phase 2b dose finding study in Pso as well as a Phase 2 study in ulcerative colitis (UC) in 2022. We continue to develop our SIK portfolio of molecules, and recently reported encouraging early data from the first patient studies with SIK2/3 inhibitor GLPG3970. In a Phase 1b trial in Pso (CALOSOMA), clinical activity was observed at 6 weeks, and in a Phase 2a trial in UC (SEA TURTLE), biologically important effects were observed on a number of objective endpoints, both of which point to the potential of SIK inhibition as a novel mode of action in inflammation. No activity was observed in the LADYBUG study in rheumatoid arthritis (RA). GLPG3970 was generally safe and well tolerated. Based on these encouraging data, we work on optimizing the pharmacology of follow-up compounds from our SIK portfolio, and plan to bring an improved SIK2/3 molecule into the clinic in 2022. On the commercial side, we report rapid progress in establishing our commercial operations for Jyseleca across Europe, with 11 countries launched to date. Reimbursement procedures are on track, and we are on target to achieve our commercial objectives. We remain excited about the potential of our target discovery platform, our drug development capabilities, and the strength of our teams. We want to thank our shareholders for their continued support and patience as we are working hard to build our pipeline and establish Galapagos as a fully integrated European biopharma,” said Onno van de Stolpe, CEO of Galapagos. Bart Filius, President and COO, added, “Following the strategic exercise announced at Q1, we are focused on advancing our pipeline, implementing our savings program, and diligently evaluating business development opportunities. At the same time, we have been delivering on the launch of Jyseleca, building out our organization in new European markets. In line with our review, we reiterate our 2021 operational cash burni guidance of between €580 million and €620 million. We believe that the decisions and actions taken put us on the strongest footing for the future. We look forward to a busy second half of the year, not the least of which is the expected outcome of the regulatory review in Europe of Jyseleca in UC.” Key figures first half-year report 2021 (unaudited)(€ millions, except basic & diluted loss per share) (*) The 2020 comparatives have been restated to consider the impact of classifying the Fidelta business as discontinued operations in 2020. Details of the financial resultsDue to the sale of our fee-for-service business (Fidelta) to Selvita on 4 January 2021 for a total consideration of €37.1 million (including customary adjustments for net cash and working capital), the results of Fidelta are presented as “Net profit from discontinued operations” in our unaudited condensed consolidated income statements for the six months ended 30 June 2021 and 30 June 2020. Revenues and other income from continuing operationsOur revenues and other income from continuing operations for the first six months of 2021 increased to €277.2 million compared to €217.2 million in the first six months of 2020. Our revenues from the Gilead collaboration in the first six months of 2021 (€253.2 million) related to (i) the exclusive access to our drug discovery platform (€115.7 million), (ii) the filgotinib revenue recognition (€136.1 million) and (iii) royalties (€1.4 million). Our deferred income balance on 30 June 2021 includes €1.9 billion allocated to our drug discovery platform that is recognized linearly over 10 years, and €0.7 billion allocated for the filgotinib development (including considerations for the previous and the renegotiated collaboration combined) that is recognized over time until the end of the development period. Results from continuing operationsWe realized a net loss from continuing operations of €77.2 million for the first six months of 2021, compared to a net loss of €169.2 million for the first six months of 2020. We reported an operating loss amounting to €97.6 million for the first six months of 2021, compared to an operating loss of €134.4 million for the same period last year. Our R&D expenditure in the first six months of 2021 amounted to €268.8 million, compared to €262.9 million for the first six months of 2020. This increase, primarily related to our filgotinib program and our Toledo program, was compensated by a decrease for ziritaxestat, the osteoarthritis (OA) program with GLPG1972, and the program in atopic dermatitis (AtD) with MOR106. Personnel costs increased due to an increase in headcount compared to the same period last year and increased costs of our subscription right plans. This factor, and the increased cost of the commercial launch of filgotinib in Europe, contributed to the increase in our S&M and G&A expenses, which were respectively €29.1 million and €76.9 million in the first six months of 2021, compared to respectively €26.9 million and €61.8 million in the first six months of 2020. We reported a non-cash fair value gain from the re-measurement of initial warrant B issued to Gilead, amounting to €2.8 million, mainly due to the decreased implied volatility of the Galapagos share price and its evolution between 31 December 2020 and 30 June 2021. Net other financial income in the first six months of 2021 amounted to €17.1 million, compared to net other financial loss of €13.0 million for the first six months of 2020, which was primarily attributable to €33.4 million of currency exchange gain on our cash and cash equivalents and current financial investments in U.S. dollars, to €8.7 million of negative changes in (fair) value of current financial investments and financial assets and to €4.4 million of interest expenses. The other financial expenses also contained the effect of discounting our long term deferred income of €4.8 million. Results from discontinued operationsThe net profit from discontinued operations for the six months ended 30 June 2021 consisted of the gain on the sale of Fidelta, our fee-for-services business, for €22.2 million. Group net resultsWe reported a group net loss for the first six months of 2021 of €55.0 million, compared to a group net loss of €165.6 million for the first six months of 2020. Cash positionCurrent financial investments and cash and cash equivalents totaled €5,006.6 million on 30 June 2021, as compared to €5,169.3 million on 31 December 2020. Total net decrease in cash and cash equivalents and current financial investments amounted to €162.7 million during the first six months of 2021, compared to a net decrease of €214.3 million during the first six months of 2020. This net decrease was composed of (i) €223.2 million of operational cash burn, (ii) offset by €2.6 million of cash proceeds from capital and share premium increase from exercise of subscription rights in the first six months of 2021, (iii) €5.8 million negative changes in (fair) value of current financial investments and €35.0 million of mainly positive exchange rate differences, (iv) €28.7 million cash in from disposal of subsidiaries, net of cash disposed. Finally, our balance sheet on 30 June 2021 held a receivable from the French government (Crédit d’Impôt Rechercheiv) and a receivable from the Belgian Government for R&D incentives, for a total of both receivables of €142.7 million. Outlook 2021In 2021, we expect the European regulatory assessment of filgotinib for the treatment of UC and anticipate both an opinion from the Committee for Medicinal Products for Human Use (CHMP) and a decision from the European Commission later this year. We also expect additional reimbursement decisions for filgotinib in RA across a number of European countries. We are on track to complete the transition from our collaboration partner Gilead to us of the full European commercial operations for filgotinib by year-end, and we anticipate reporting on our own European sales of filgotinib starting in the second half of the year. Completion of the recruitment in the global DIVERSITY Phase 3 trial with filgotinib in Crohn’s disease by our collaboration partner Gilead is also expected later this year. With regard to our SIK portfolio, we are advancing our SIK3 inhibitor GLPG4399 in healthy volunteers this year, and we aim to advance a follow-up SIK2/3 preclinical candidate into the clinic in 2022. Following the positive topline data from our TYK2 inhibitor, GLPG3667, we currently are running an extended dose escalation study in healthy volunteers, and we are preparing for a Phase 2b trial in Pso and a Phase 2 trial in UC next year. In our other programs, by year-end we intend to finalize recruitment into the GLPG2737 Phase 2a trial in polycystic kidney disease. Following the previously announced review of our plans for 2021, we reiterate our guidance for full year 2021 operational cash burn of €580 to €620 million. First half-year report 2021 Galapagos’ financial report for the first half-year ended 30 June 2021, including details of the unaudited consolidated results, is accessible via . Conference call and webcast presentation Galapagos will conduct a conference call open to the public tomorrow, 6 August 2021, at 14:00 CET / 8 AM ET, which will also be webcasted. To participate in the conference call, please call one of the following numbers ten minutes prior to commencement: CODE: 8245817 A question and answer session will follow the presentation of the results. Go to to access the live audio webcast. The archived webcast will also be available for replay shortly after the close of the call. Financial calendar About Galapagos Galapagos NV discovers and develops small molecule medicines with novel modes of action, several of which show promising patient results and are currently in clinical development in multiple diseases. Our pipeline comprises discovery through Phase 3 programs in inflammation, fibrosis and other indications. Our ambition is to become a leading global biopharmaceutical company focused on the discovery, development, and commercialization of innovative medicines. More information at . Except for filgotinib’s approval for the treatment of rheumatoid arthritis by the European Commission, Great Britain’s Medicines and Healthcare products Regulatory Agency and Japanese Ministry of Health, Labour and Welfare, our drug candidates are investigational; their efficacy and safety have not been fully evaluated by any regulatory authority. Jyseleca® is a trademark of Galapagos NV and Gilead Sciences, Inc. or its related companies. Contact Investors:Elizabeth GoodwinVP Investor Relations +1 781 460 1784 Sofie Van GijselSenior Director Investor Relations+1 781 296 1143 Sandra CauwenberghsDirector Investor Relations+32 495 58 46 63ir@glpg.com Media:Carmen VroonenGlobal Head of Communications & Public Affairs+32 473 824 874 communications@glpg.com Forward-looking statements This release may contain forward-looking statements, including, among other things, statements regarding the global R&D collaboration with Gilead, the amount and timing of potential future milestones, opt-in and/or royalty payments by Gilead, Galapagos’ strategic R&D ambitions, including progress on our fibrosis portfolio and Toledo platform, and potential changes of such ambitions, the guidance from management (including guidance regarding the expected operational use of cash during financial year 2021), financial results, statements regarding the expected timing, design and readouts of ongoing and planned clinical trials, including recruitment for trials and topline results for our trials and studies in our inflammation portfolio, statements regarding the strategic re-evaluation, statements relating to interactions with regulatory authorities, the timing or likelihood of additional regulatory authorities’ approval of marketing authorization for filgotinib for RA, UC or any other indication, including UC and IBD indication for filgotinib in Europe, Great-Britain, Japan, and the U.S., such additional regulatory authorities requiring additional studies, the timing or likelihood of pricing and reimbursement interactions for filgotinib, statements relating to the build-up of our commercial organization, statements and expectations regarding commercial sales for filgotinib, the expected impact of COVID-19, and our strategy, business plans and focus. Galapagos cautions the reader that forward-looking statements are not guarantees of future performance. Forward-looking statements involve known and unknown risks, uncertainties and other factors which might cause the actual results, financial condition and liquidity, performance or achievements of Galapagos, or industry results, to be materially different from any historic or future results, financial conditions and liquidity, performance or achievements expressed or implied by such forward-looking statements. In addition, even if Galapagos’ results, performance, financial condition and liquidity, and the development of the industry in which it operates are consistent with such forward-looking statements, they may not be predictive of results or developments in future periods. Among the factors that may result in differences are that our expectations regarding our 2021 revenues and financial results and our 2021 operating expenses may be incorrect (including because one or more of its assumptions underlying its expense expectations may not be realized), Galapagos’ expectations regarding its development programs may be incorrect, the inherent uncertainties associated with competitive developments, clinical trial and product development activities and regulatory approval requirements (including the risk that data from Galapagos’ ongoing and planned clinical research programs in rheumatoid arthritis, Crohn’s disease, ulcerative colitis, idiopathic pulmonary fibrosis, osteoarthritis, other inflammatory indications and kidney disease may not support registration or further development of its product candidates due to safety, efficacy or other reasons), Galapagos’ reliance on collaborations with third parties (including our collaboration partner Gilead), the timing of and the risks related to the implementation of the transition of the European commercialization responsibility of filgotinib from Gilead to us, estimating the commercial potential of our product candidates and Galapagos’ expectations regarding the costs and revenues associated with the transfer of European commercialization rights to filgotinib may be incorrect, and the uncertainties relating to the impact of the COVID-19 pandemic. A further list and description of these risks, uncertainties and other risks can be found in Galapagos’ Securities and Exchange Commission (SEC) filings and reports, including in Galapagos’ most recent annual report on Form 20-F filed with the SEC and other filings and reports filed by Galapagos with the SEC. Given these uncertainties, the reader is advised not to place any undue reliance on such forward-looking statements. These forward-looking statements speak only as of the date of publication of this document. Galapagos expressly disclaims any obligation to update any such forward-looking statements in this document to reflect any change in its expectations with regard thereto or any change in events, conditions or circumstances on which any such statement is based or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements, unless specifically required by law or regulation. i The operational cash burn (or operational cash flow if this performance measure is positive) is equal to the increase or decrease in our cash and cash equivalents (excluding the effect of exchange rate differences on cash and cash equivalents), minus: This alternative performance measure is in our view an important metric for a biotech company in the development stage. The operational cash burn for the six months ended 30 June 2021 amounted to €223.2 million and can be reconciled to our cash flow statement by considering the increase in cash and cash equivalents of €477.4 million, adjusted by (i) the cash proceeds from capital and share premium increase from the exercise of subscription rights by employees for €2.6 million, (ii) the net sale of current financial investments amounting to €669.4 million, and (iii) the cash in from sale of subsidiaries, net of cash disposed, of €28.7 million.   ii General and administrativeiii Sales and marketingiv Crédit d’Impôt Recherche refers to an innovation incentive system underwritten by the French government Attachment

Mechelen, Belgium; 14 July 2021; 22.01 CET; regulated information – Galapagos NV (Euronext & Nasdaq: GLPG) reports topline results with GLPG3970 in three patient studies. GLPG3970, the first product candidate from a broad portfolio of SIK inhibitor compounds, provides clinical data supporting the role of SIK inhibition in inflammation. SIK is a novel target class discovered by Galapagos. Galapagos evaluated GLPG3970, a proprietary salt inducible kinase (SIK) 2/3 inhibitor, in three randomized, placebo-controlled, double-blind studies: a Phase 1b study in patients with moderate to severe psoriasis and two Phase 2a studies in patients with moderate to severely active UC and RA. GLPG3970 or placebo were administered orally once-daily for 6 weeks. Main objectives were to evaluate the safety and tolerability of GLPG3970 as well as early signs of biologic and clinical effect. Across the three studies, GLPG3970 was generally safe and well tolerated. There were no deaths nor serious adverse events, and the majority of treatment emergent adverse events (TEAEs) were mild or moderate in nature. CALOSOMA study: Phase 1b trial in psoriasisThis study randomized 26 patients with moderate to severe psoriasis in a 3:2 ratio, GLPG3970 to placebo. Two out of 15 patients discontinued in the treatment arm (COVID-19 and pruritus) versus 1 out of 11 on placebo (psoriatic arthropathy). At Week 6, four out of 13 patients on GLPG3970 had a PASI1 50 response, defined as at least a 50% improvement of baseline PASI, compared to none on placebo. Specifically, the four responders achieved 50%, 50%, 56%, and 77% improvement in their PASI scores from baseline, reaching statistical significance compared to placebo (p=0.002) at Week 6. Positive signals of clinical effect were also consistently observed for other endpoints, including affected Body Surface Area and physician and patient global assessment, versus placebo at Week 6. SEA TURTLE study: Phase 2a trial in UCThis study randomized 31 biologic-naïve patients with moderate to severely active UC in a 2:1 ratio, GLPG3970 to placebo. One out of 21 patients discontinued in the active treatment arm (COVID-19) versus one out of 10 on placebo (QT abnormality at baseline). At Week 6, positive signals were observed in patients on GLPG3970 on objective parameters such as endoscopy, histology, and fecal calprotectin. These findings did not translate in a differentiation from placebo on change from baseline total Mayo Clinic Score in this 6-week study (GLPG3970 -2.7, placebo -2.6). Seven out of 18 patients on GLPG3970 who underwent endoscopy at Week 6 met the criteria for Endoscopic Improvement, defined as a score of 0 or 1 on the endoscopic response score, compared to one out of 9 patients on placebo. The robustness of these signals will be further examined when additional efficacy and biomarker data become available later this year. LADYBUG study: Phase 2a trial in RAThis study randomized 28 patients with moderate to severely active RA and an inadequate response to methotrexate in a 3:2 ratio, GLPG3970 to placebo. Three out of 16 patients discontinued in the treatment arm (COVID-19, ALT increase and physician decision) versus 2 out of 12 on placebo (COVID-19). At Week 6, patients on GLPG3970 showed no differentiation from placebo on change from baseline DAS28 (CRP)2 response (GLPG3970 -1.29, placebo -1.24), nor on the majority of other efficacy endpoints. Further development of Toledo product portfolioGLPG3970 is the first compound from Galapagos’ broad portfolio of novel molecules to provide clinical evidence for the potential role of SIK inhibition in inflammation. Biomarker data from these signal-finding studies with GLPG3970 will be further analyzed for signature profiles. Our aim with the Toledo program is to  explore this novel mode of action fully and bring forward improved molecules directed toward SIK2/3 as well as other SIK selectivity profiles. Galapagos currently has two compounds exhibiting SIK2/3 inhibition in preclinical development. “We are excited to demonstrate, for the first time, important biologic and clinical effects with a SIK inhibitor in patients with inflammatory conditions. This is a major achievement when working on a novel mode of action target class. The CALOSOMA trial in psoriasis patients indicates clear proof of activity and the SEA TURTLE trial in ulcerative colitis patients provides encouraging results that support further development with Toledo compounds with improved pharmacology. In addition, these studies in patients confirm the safety and tolerability profile previously observed in healthy volunteers,” said Dr. Walid Abi-Saab, Chief Medical Officer of Galapagos. “The GLPG3970 broad dataset is an important step forward, and we aim to apply key learnings from these studies to the further development of our Toledo portfolio of SIK inhibitors.” Galapagos intends to submit study outcomes with GLPG3970 for publication at scientific conferences and in peer-reviewed medical journals. About Toledo“Toledo” is an extensive program with a novel target class, SIK, whose potential role in inflammation was discovered by Galapagos. The Toledo program aims to treat a broad range of autoimmune conditions with important unmet medical needs. The Toledo platform delivers small molecule inhibitors of SIK targets with different selectivity profiles. The most advanced compound, SIK2/3 inhibitor GLPG3970, has shown immunomodulatory activity in vitro preclinically and ex vivo clinically with what Galapagos believes is a dual mode of action characterized by enhanced transcription of anti-inflammatory cytokines and inhibited transcription of pro-inflammatory cytokines. SIK inhibition has previously shown encouraging preclinical activity in a range of inflammatory disease models. GLPG3970 is an investigational drug and not approved by any regulatory authority. Its efficacy and safety have not been established. About GalapagosGalapagos NV (Euronext & NASDAQ: GLPG) discovers and develops small molecule medicines with novel modes of action, several of which show promising patient results and are currently in clinical development in multiple diseases. Our pipeline comprises discovery through Phase 3 programs in inflammation, fibrosis, and other indications. Our ambition is to become a leading global biopharmaceutical company focused on the discovery, development, and commercialization of innovative medicines. More information at . This press release contains inside information within the meaning of Regulation (EU) No 596/2014 of the European Parliament and of the Council of 16 April 2014 on market abuse (market abuse regulation). Contacts Investors:Elizabeth GoodwinVP Investor Relations +1 781 460 1784 Sofie Van GijselSenior Director Investor Relations+1 781 296 1143 ir@glpg.com Media:Kyra ObolenskySenior Director Corporate Communications+32 491 92 64 35 Evelyn FoxDirector Executive Communications+31 65 3591 999communications@glpg.com Galapagos Forward-Looking Statements This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, that are subject to risks, uncertainties and other factors that could cause actual results to differ materially from those referred to in the forward-looking statements and, therefore, the reader should not place undue reliance on them. These risks, uncertainties and other factors include, without limitation, the risk that ongoing and future clinical studies with GLPG3970 may not be completed in the currently envisaged timelines or at all, the inherent uncertainties associated with competitive developments, clinical trial and product development activities and regulatory approval requirements (including that data from the ongoing and planned clinical research programs may not support registration or further development of GLPG3970 due to safety, efficacy or other reasons), Galapagos' reliance on collaborations with third parties and that Galapagos’ estimations regarding its GLPG3970 development program and regarding the commercial potential of GLPG3970 as well as regarding its Toledo platform, may be incorrect, as well as those risks and uncertainties identified in our Annual Report on Form 20-F for the year ended 31 December 2020 and our subsequent filings with the SEC. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. The forward-looking statements contained herein are based on management’s current expectations and beliefs and speak only as of the date hereof, and Galapagos makes no commitment to update or publicly release any revisions to forward-looking statements in order to reflect new information or subsequent events, circumstances or changes in expectations. 1 Psoriasis Area and Severity Index; an index used to express the severity of psoriasis. It combines the severity (erythema, induration and desquamation) and percentage of affected area 2 DAS28 is a RA Disease Activity Score based on a calculation that uses tender and swollen joint counts of 28 defined joints, the physician’s global health assessment and a serum marker for inflammation, such as C-reactive protein. DAS28 (CRP) includes the C-reactive protein score calculation Attachment