PLK1 x TTK

Upfront and near-term milestone payments of USD 14 million Additional milestone payments of approximately USD 320 million and tiered royalties on net salesSecond oncology transaction as part of strategic refocusing on anti-infectivesFull-year 2022 revenue guidance increased, resulting in improved expected operating result and operating cash flow Ad hoc announcement pursuant to Art. 53 LR Basel/Allschwil, Switzerland, September 20, 2022 Basilea Pharmaceutica Ltd. (SIX: BSLN), a commercial-stage biopharmaceutical company committed to meeting the needs of patients with severe bacterial and fungal infections, announced today that it has entered into an asset purchase agreement and a sub-license agreement with SillaJen, Inc. for Basilea’s novel kinase inhibitor, BAL0891, a potential first-in-class mitotic checkpoint inhibitor, that drives aberrant tumor cell division leading to tumor cell death. Basilea in-licensed BAL0891 in 2018 from the Dutch precision medicine company NTRC. Under the asset purchase agreement Basilea is selling its intellectual property rights generated under the license and collaboration agreement with NTRC. In addition, Basilea is sub-licensing its rights and obligations under the license and collaboration agreement with NTRC to SillaJen. Adesh Kaul, Chief Financial Officer of Basilea, said: “We are pleased to have found in SillaJen an experienced oncology partner for the further development of BAL0891. This transaction marks an important step on our path to be a focused anti-infectives company. We are proud to have advanced BAL0891 through preclinical development to the start of clinical studies. The unique inhibition profile of BAL0891, targeting both TTK and PLK1 kinases, differentiates the compound and offers the potential for development in multiple cancers. Through the structure of the transaction we continue to participate in the long-term value creation potential of this promising program.” Jaegyeong Kim, MD, CEO at SillaJen, Inc. stated: “We are excited to acquire the rights to BAL0891. This agreement for a first-in-class anti-cancer drug, demonstrates our commitment to enhance lives of patients suffering from advanced solid tumors. In addition to our leading pipeline of Pexa-Vec, and the next generation SJ-600 series of oncolytic virus modalities, we are committed to advance and further develop medicines that will address the greatest unmet needs in cancer treatment. We hope to successfully deliver these products and help alleviate the burden of cancer patients worldwide." Under the terms of the agreement, Basilea will receive upfront and near-term milestone payments of USD 14 million. Basilea is also eligible to receive further payments of up to approximately USD 320 million upon the achievement of predefined development, regulatory and sales milestones and tiered royalties on net sales starting in the single digit range going up to double-digits. Basilea remains responsible for making milestone and royalty payments to NTRC according to the license and collaboration agreement with NTRC. In February this year Basilea announced its intention to focus on becoming a leading anti-infectives company and therefore to separate its oncology assets. Basilea has already made significant progress in the implementation of the new strategy and expects no material expenses related to oncology activities beyond 2022. Basilea is on track to achieve sustainable profitability from 2023. Basilea updates its full-year 2022 financial guidance. It expects higher total revenues of CHF 116 to 122 million (previously CHF 106 to 112 million), an improved operating result of CHF -10 to -15 million (previously CHF -20 to -25 million) and improved cash flow from operating activities of CHF 0 to -5 million (previously CHF -10 to -15 million). About SillaJen, Inc. SillaJen, Inc. (KOSDAQ:215600) is one of the leading biotech companies in the development of oncolytic vaccinia immunotherapy. It is headquartered in Seoul, South Korea, with research center and satellite offices in Busan, South Korea and San Francisco, CA. SillaJen, Inc. is conducting Phase 2 trials for the treatment of renal cell carcinoma with the company’s lead pipeline, Pexa-Vec. The company is also developing intravenous injectable oncolytic vaccinia virus pipelines (SJ-600 series) to be more applicable and efficacious against various tumors. Additional information about SillaJen, Inc. is available at www.sillajen.com. About BAL0891 BAL0891 is a first-in-class mitotic checkpoint inhibitor that pushes cells through mitosis without adequate time for correct chromosome segregation. This results in aberrant tumor cell division leading to tumor cell death. The compound is a unique dual inhibitor of threonine tyrosine kinase (TTK) and polo-like kinase 1 (PLK1). Both kinases collaborate in activating the mitotic spindle assembly checkpoint (SAC), a cell division mechanism regulating correct chromosome alignment and segregation. The dual action of BAL0891 leads to a rapid disruption of the SAC driving cells through mitosis before the chromosomes are properly aligned, leading to premature cell division and tumor cell death. BAL0891 has shown anti-proliferative activity across diverse tumor cell lines in vitro and single agent efficacy in in-vivo models of solid human cancers. BAL0891 was in-licensed from NTRC in 2018. About Basilea Basilea is a commercial-stage biopharmaceutical company founded in 2000 and headquartered in Switzerland. We are committed to discovering, developing and commercializing innovative drugs to meet the needs of patients with severe bacterial and fungal infections. We have successfully launched two hospital brands, Cresemba for the treatment of invasive fungal infections and Zevtera for the treatment of bacterial infections. In addition, we have several preclinical anti-infective assets in our portfolio. Basilea is listed on the SIX Swiss Exchange (SIX: BSLN). Please visit basilea.com. Disclaimer This communication expressly or implicitly contains certain forward-looking statements, such as "believe", "assume", "expect", "forecast", "project", "may", "could", "might", "will" or similar expressions concerning Basilea Pharmaceutica Ltd and its business, including with respect to the progress, timing and completion of research, development and clinical studies for product candidates. Such statements involve certain known and unknown risks, uncertainties and other factors, which could cause the actual results, financial condition, performance or achievements of Basilea Pharmaceutica Ltd to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Basilea Pharmaceutica Ltd is providing this communication as of this date and does not undertake to update any forward-looking statements contained herein as a result of new information, future events or otherwise. For further information, please contact: Peer Nils Schröder, PhD Head of Corporate Communications & Investor RelationsBasilea Pharmaceutica International Ltd, Allschwil Hegenheimermattweg 167b4123 AllschwilSwitzerland Phone +41 61 606 1102 E-mail media_relations@basilea.cominvestor_relations@basilea.com This ad hoc announcement can be downloaded from www.basilea.com. Attachment Press release (PDF)

Basilea Pharmaceutica Ltd. (SIX: BSLN), a commercial-stage biopharmaceutical company committed to meeting the needs of patients with infectious diseases and cancer, reported today that promising preclinical data on the anti-cancer activity of its three oncology drug candidates, BAL0891, derazantinib and lisavanbulin, have been presented at the Annual Meeting of the American Association for Cancer Research (AACR) that took place April 8-13, 2022, in New Orleans, USA. BAL0891 is a potential first-in-class mitotic checkpoint inhibitor (MCI) that drives aberrant tumor cell division leading to tumor cell death. A first poster showed in-vitro data on the activity of BAL0891 against its targets, threonine tyrosine kinase (TTK) and polo-like-kinase 1 (PLK1). The activity of BAL0891 led to a faster disruption of the mitotic spindle assembly check point (SAC) than TTK- and PLK1-specific inhibitors alone. This was associated with a broad anti-cancer effect across diverse tumor cell lines, including those derived from breast, gastric and colorectal cancer. Data presented on a second poster confirmed the good tolerability and potent single-agent anti-cancer activity of BAL0891 across a panel of patient-derived xenograft (PDX) in-vivo models of triple-negative breast cancer. Complete tumor regressions were observed in a significant number of PDX models and support the further development of BAL0891 for the potential treatment of human cancer. The data on both posters were generated in collaboration with the Dutch precision medicine company, NTRC B.V., from which Basilea in-licensed the drug candidate. Dr. Laurenz Kellenberger, Chief Scientific Officer of Basilea, said: “The data presented at the AACR Annual Meeting confirm the differentiated profiles of our drug candidates. For BAL0891, the in-vitro an in-vivo data provide additional support for the novel mode of action of our compound and its potent single-agent activity. We are particularly pleased that BAL0891 shows convincing activity in models of human triple-negative breast cancer, a difficult-to-treat cancer with a high medical need.” Further in-vitro and in-vivo data was also presented for derazantinib, a fibroblast growth factor receptor (FGFR) inhibitor, confirming similar sensitivity of FGFR1-3 and colony stimulating factor 1 receptor (CSF1R) to derazantinib. CSF1R plays an important role in the anti-tumor immune response to PD-L1 checkpoint inhibitors used for cancer therapy. In-vivo tumor models with high CSF1R levels were partially sensitive to derazantinib, but not to another FGFR inhibitor with no activity against CSF1R. The importance of the additional CSF1R inhibition was highlighted by data that showed a synergistic effect of the combination of derazantinib with a PD-L1 antibody in an immunologically competent breast cancer model. As compared to the single agents, this combination increased efficacy against the primary tumor, and liver and lung metastases. The combination also led to a more pronounced activation of the immune microenvironment in the primary tumor. Finally, preclinical data were presented on avanbulin, the active moiety of Basilea’s tumor checkpoint controller lisavanbulin. In-vitro, avanbulin treatment was associated with high anti-tumor activity in models of diffuse large B cell lymphoma (DLBCL), supporting a potential application of lisavanbulin for the treatment of lymphoma patients. These data were generated in collaboration with Prof. Bertoni (Institute of Oncology Research, USI, Bellinzona, Switzerland).