"The third quarter of 2019 was a productive period for SpringWorks as we completed a successful initial public offering while simultaneously achieving important regulatory and clinical development milestones, including dosing the first patient in our Phase 2b ReNeu trial of mirdametinib for patients with plexiform neurofibromas," said Saqib Islam, Chief Executive Officer of SpringWorks. "Our team is focused on enrolling patients in our two potentially registrational trials in rare oncology indications and our Phase 1b trial in patients with RAS and RAF mutated solid tumors, and collaborating with our partners to initiate two additional Phase 1 studies in genetically defined cancers by early next year. We also continue to evaluate new business development opportunities to expand our pipeline and maximize the value of our portfolio."

• Initiated Potentially Registrational ReNeu Clinical Trial: In October 2019, SpringWorks announced the initiation of the Phase 2b ReNeu clinical trial evaluating mirdametinib in children and adults with neurofibromatosis type 1-associated plexiform neurofibromas (NF1-PN).
• Completed Successful Initial Public Offering: In September 2019, SpringWorks completed its initial public offering of 10,350,000 shares of common stock, including the exercise in full by the underwriters of their option to purchase up to 1,350,000 additional shares of its common stock, at the public offering price of $18.00 per share. The Company raised $186.3 million in aggregate gross proceeds.
• Received EU Orphan Drug Designation for Nirogacestat: In September 2019, the European Commission granted Orphan Drug Designation for nirogacestat for the treatment of soft tissue sarcoma.
• Received Breakthrough Therapy Designation for Nirogacestat: In August 2019, the U.S. Food and Drug Administration granted Breakthrough Therapy Designation to nirogacestat for the treatment of adult patients with progressive, unresectable, recurrent or refractory desmoid tumors or deep fibromatosis.
• Strengthened Leadership Team and Board of Directors: In August 2019, SpringWorks appointed Francis (Frank) I. Perier, Jr. as Chief Financial Officer and Alan Fuhrman to its Board of Directors and as Audit Committee Chair.
• Received EU Orphan Drug Designation for Mirdametinib: In July 2019, the European Commission granted Orphan Drug Designation for mirdametinib for the treatment of neurofibromatosis type 1 (NF1).

• Research and Development (R&D) Expenses: R&D expenses as of September 30, 2019 were $10.7 million and $30.4 million for the third quarter and year-to-date periods, respectively, compared to $3.4 million and $6.2 million for the comparable periods of 2018, respectively. The increases in R&D expenses in 2019 are primarily attributable to increased clinical study and drug supply costs related to the ongoing Phase 3 DeFi and Phase 2b ReNeu trials, as well as growth in employee costs, including non-cash share-based compensation associated with increases in the number of R&D personnel.
• General and Administrative (G&A) Expenses: G&A expenses as of September 30, 2019 were $4.6 million and $11.5 million for the third quarter and year-to-date periods, respectively, compared to $1.8 million and $5.9 million for the comparable periods of 2018, respectively. The increases in G&A expenses in 2019 are primarily attributable to growth in employee costs, including non-cash share-based compensation associated with increases in the number of G&A personnel, and increases in consulting and professional services related to the expansion of our business activities.
• Net Loss Attributable to Common Stockholders: As of September 30, 2019, SpringWorks reported net losses of $16.8 million, or $1.77 loss per share, and $34.4 million, or $9.24 loss per share, for the third quarter and year-to-date periods respectively. This compares to net losses of $5.0 million, or $11.55 loss per share, and $11.6 million, or $44.20 loss per share, for the comparable periods of 2018, respectively.
• Cash Position: Cash and cash equivalents were $343.8 million as of September 30, 2019. This includes net proceeds of $169.7 million from SpringWorks' initial public offering completed in September 2019.

SpringWorks is a clinical-stage biopharmaceutical company applying a precision medicine approach to acquiring, developing and commercializing life-changing medicines for underserved patient populations suffering from devastating rare diseases and cancer. SpringWorks has a differentiated portfolio of small molecule targeted oncology product candidates and is advancing two potentially registrational clinical trials in rare tumor types, as well as several other programs addressing highly prevalent, genetically defined cancers. SpringWorks' strategic approach and operational excellence in clinical development have enabled it to rapidly advance its two lead product candidates into late-stage clinical trials while simultaneously entering into multiple shared-value partnerships with industry leaders to expand its portfolio. For more information, please visit www.springworkstx.com.

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Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding SpringWorks' clinical trials and its strategy, business plans and focus. The words "may," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "estimate," "predict," "project," "potential," "continue," "target" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, those related to the timing for completion of SpringWorks' clinical trials of its product candidates, whether and when, if at all, SpringWorks' product candidates will receive approval from the U.S. Food and Drug Administration, or FDA, or other foreign regulatory authorities, competition from other biopharmaceutical companies, and other risks identified in SpringWorks' SEC filings, including its final prospectus for its initial public offering filed on September 13, 2019 and subsequent filings with the SEC. SpringWorks cautions you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. SpringWorks disclaims any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements. Any forward-looking statements contained in this press release represent SpringWorks' views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date.