Eidos Therapeutics Receives Positive Opinion for Orphan Designation from the European Medicines Agency for AG10, a Potent Oral Stabilizer for the Treatment of Transthyretin Amyloidosis

SAN FRANCISCO, Oct. 26, 2018 (GLOBE NEWSWIRE) — Eidos Therapeutics, Inc. (Eidos) (Nasdaq:EIDX), announced today that the Committee for Orphan Medicinal Products (COMP) within the European Medicines Agency (EMA) adopted a positive opinion for the designation of Eidos’ product candidate, AG10, as an orphan medicinal product for the treatment of transthyretin (TTR) amyloidosis (ATTR). In addition, the EMA also granted a product-specific pediatric investigational plan waiver to Eidos for AG10.

TTR normally circulates as a four-part molecule or tetramer, but in ATTR the molecule dissociates into individual monomers, which are unstable and aggregate as amyloid fibrils. Eidos’ lead product candidate, AG10, is designed to target ATTR at its source by stabilizing tetrameric TTR in the blood.

“We are pleased to have received Orphan Drug Designation from the FDA and now a positive opinion from the EMA as well. Eidos is excited about the opportunity to work with the ATTR patient and provider community on the further development of AG10 for ATTR,” noted Jonathan Fox, M.D., Ph.D., president and chief medical officer of Eidos. “Importantly, AG10 has demonstrated potent stabilization of tetrameric TTR in our clinical program, and we believe maximizing the level of TTR stabilization will lead to optimal clinical benefit for patients living with this devastating disease.”

Orphan Designation by the European Commission provides regulatory and financial incentives for the development of medicines that treat a

life-threatening or chronically debilitating condition affecting less than five in 10,000 people in the European Union (EU). Orphan Designation provides Eidos with certain benefits, including EU market exclusivity upon regulatory approval, if received, reductions in EMA application fees, and access to protocol assistance. Eidos is pursuing AG10 for the treatment of ATTR cardiomyopathy (ATTR-CM) and ATTR polyneuropathy (ATTR-PN), both of which are progressive, fatal diseases. The company plans to initiate Phase 3 studies in each indication in the first half of 2019.

About AG10

AG10 is an investigational, orally administered small molecule designed to potently stabilize tetrameric transthyretin, or TTR, thereby halting at its outset the series of molecular events that give rise to amyloidosis, or ATTR. AG10 is currently being examined in a Phase 2 clinical trial in patients with ATTR cardiomyopathy and symptomatic heart failure. Results from this trial will be presented on November 10, 2018 at the American Heart Association’s Annual Scientific Sessions.

AG10 was designed to mimic a naturally-occurring variant of the TTR gene (T119M) that is considered a “rescue mutation” because it has been shown to prevent ATTR in individuals also carrying a pathogenic, or disease-causing, mutation in the other copy of their TTR gene. To our knowledge, AG10 is the only TTR stabilizer in development that has been observed to mimic the “super-stabilizing” properties of this rescue mutation.

About Eidos Therapeutics

Eidos Therapeutics is a clinical stage biopharmaceutical company focused on addressing the large and growing unmet need in diseases caused by transthyretin (TTR) amyloidosis (ATTR). For more information, please visit www.eidostx.com.

Forward-Looking Statements

This release includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act. All statements other than statements of historical facts, including the statements about future clinical milestones of AG10, including the completion of our ongoing Phase 2 clinical trial and availability of data therefrom, the initiation of Phase 3 clinical trials, the timing of these events, the indications we intend to pursue, the potential benefits available to us from orphan drug designations for AG10, and our possible clinical or other business strategies, are forward-looking statements. Forward-looking statements can be identified by terms such as “believes,” “expects,” “plans,” “potential,” “would” or similar expressions and the negative of those terms. These forward-looking statements are based on our management’s current beliefs and assumptions about future events and on information currently available to management.

Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These risks include, but are not limited to, risks and uncertainties related to: our limited operating history and historical losses, our liquidity to fund the development of our other product candidates through current and future milestones, our ability to raise additional funding to complete the development and any commercialization of our product candidates, our dependence on the success of our lead product candidate, AG10, results from our clinical trials and pre-clinical studies and those of third parties working in the same area as our product candidate and our dependence on third parties in connection with our manufacturing, clinical trials and pre-clinical studies. Additional risks and uncertainties that could affect our future results are included in the section titled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2018, which is available on the SEC’s website at www.sec.gov and our website at eidostx.com. Additional information on potential risks will be made available in other filings that we make from time to time with the SEC. In addition, any forward-looking statements contained in this press release are based on assumptions that we believe to be reasonable as of this date. Except as required by law, we assume no obligation to update these forward-looking statements, or to update the reasons if actual results differ materially from those anticipated in the forward-looking statements.

Media Contact:

Carolyn Hawley, Canale Communications, (619) 849-5382, carolyn@canalecomm.com

For Investors

Alex Gray, Burns McClellan, (212) 213-0006, agray@burnsmc.com

Data Published in Nature Communications Demonstrates CoA Therapeutics’ Potential to Treat Genetically Driven Pantothenate Kinase-Associated Neurodegeneration (PKAN)

PALO ALTO, Calif., Oct. 23, 2018 /PRNewswire/ — CoA Therapeutics, a company developing small molecules that target Coenzyme-A for patients with PKAN and other diseases of CoA sequestration, today announced key data published by researchers from St. Jude Children’s Research Hospital in Nature Communications demonstrating the potential of small molecule activators of pantothenate kinase for the treatment of pantothenate kinase-associated neurodegeneration (PKAN) and other diseases involving CoA sequestration. In addition, the company announced that it has nominated the development candidate molecule and will commence IND-enabling studies. Finally, CoA announced the formation of a scientific advisory board that will help guide future development.

PKAN is a neurological disorder that arises from mutations in the human PANK2 gene, which codes for an enzyme called pantothenate kinase 2 (PanK2). The mutations lead to progressive difficulty with movement, speech and vision, usually beginning in childhood. There are currently no treatments approved for PKAN, which typically results in death in early adulthood.

The study, authored by St. Jude researcher Suzanne Jackowski, Ph.D., describes the discovery of a new class of compounds, the pantazines, that are designed to allosterically modulate pantothenate kinases, allowing PanK enzymes to make more CoA than they would typically make in an untreated system. The specific tool compound used in the study, PZ-2891, was found to be orally bioavailable and cross the blood brain barrier, a critical characteristic for treating neurological disorders like PKAN. In addition, in a mouse model of brain CoA deficiency, animals on PZ-2891 therapy gained weight, had improved locomotor activity and a longer life span, suggesting the compound could be a novel treatment approach for PKAN. For her role in advancing research in the field, Dr. Jackowski was awarded the Lippman Medal from the International Association for Cellular Coenzymes in July 2018.

“Dr. Jackowski’s novel approach to modulating PanK enzymes is the scientific foundation of CoA Therapeutics. In this study, we see the potential of novel allosteric modulators of PanK in increasing brain CoA levels resulting in phenotypic correction in knock-out mice. These compounds have been designed to be highly brain penetrating which is critical for diseases primarily affecting the brain such as PKAN,” said Shafique Virani, M.D., chief executive officer for CoA Therapeutics. “We will be moving rapidly to translate this exciting science to support entry of this therapeutic approach into clinical trials in PKAN and other diseases of CoA sequestration.”

Dr. Jackowski, who is a member of the faculty of St. Jude Children’s Research Hospital, will be joining CoA’s scientific advisory board. In addition to Dr. Jackowski, Hyder Jinnah, M.D., professor at Emory University School of Medicine; Nicola Longo, M.D., Ph.D., professor of pediatrics at the University of Utah, and Vernon R. Sutton, M.D., professor of molecular and human genetics at Baylor College of Medicine will join the advisory board.

About CoA Therapeutics 
CoA Therapeutics, a subsidiary of BridgeBio Pharma, is developing small molecules as targeted therapeutics for PKAN and other diseases involving CoA sequestration. The company’s mission is to improve and prolong the lives of patients suffering from PKAN and other CoA-implicated genetic disorders. Founded in 2017, CoA Therapeutics is led by a team of veteran biotechnology executives. Together with patients and physicians, the company aims to bring a safe, effective treatment to market as quickly as possible. To learn more, visit www.coatherapeutics.com.

QED Therapeutics Presents Data for Infigratinib in Cholangiocarcinoma in Late Breaking Abstract at the European Society of Medical Oncology 2018 Congress

SAN FRANCISCO, Oct. 19, 2018 /PRNewswire/ — QED Therapeutics today announced the presentation of positive, updated interim data of infigratinib (BGJ398), an orally administered, selective fibroblast growth factor receptor (FGFR) 1-3 tyrosine kinase inhibitor, for the treatment of advanced or metastatic cholangiocarcinoma (bile duct cancer) during a late-breaking poster discussion at the European Society for Medical Oncology (ESMO).

In the open-label trial, which enrolled 71 patients with FGFR2 fusions/translocations, the confirmed overall response rate (cORR) was 26.9% (95% CI 16.8-39.1%) for all patients with the potential for confirmation (n=67) and an additional 56.7% experienced stable disease as their best response, resulting in a disease control rate of 83.6%. For patients who had received one or fewer prior treatment regimens, the cORR was 39.3% (n=28), whereas patients who had received two or more treatment regimens had a cORR of 17.9%. Median progression free survival was 6.8 months (95% CI 95% CI 5.3-7.6) and median overall survival was 12.5 months (95% CI 9.9-16.6 months).

“These updated data provide the most extensive experience for an FGFR inhibitor in advanced cholangiocarcinoma,” said Milind Javle, M.D., professor, gastrointestinal medical oncology, The University of Texas MD Anderson Cancer Center and investigator on the Phase 2 infigratinib (BGJ398) study. “The high disease control rate and impressive overall survival are promising in a disease with no currently approved targeted treatments.”

“These results show that infigratinib has strong potential to make a real difference in the lives of people with cholangiocarcinoma,” said Susan Moran, M.D., M.S.C.E., chief medical officer of QED Therapeutics. “Importantly, we have initiated a pivotal, Phase 3 study in first-line cholangiocarcinoma in the hopes of offering patients an upfront chemotherapy-free treatment option.”

The study also demonstrated that infigratinib-associated toxicity is manageable. Most common treatment-emergent adverse events (TEAE) were hyperphosphatemia (73.2%), fatigue (49.3%), stomatitis (45.1%), alopecia (38.0%) and constipation (35.2%). Grade 3/4 TEAEs occurred in 47 patients (66.2%), including hypophosphatemia (14.1%), hyperphosphatemia (12.7%) and hyponatremia (11.3%).

Cholangiocarcinoma affects approximately 8,000 to 10,000 patients a year in the United States. Currently, treatment options are limited, and survival rates are generally poor.

FGFR alterations have been implicated as an oncogenic driver across multiple solid tumors and hematological cancers – including roughly one out of every five cases of cholangiocarcinoma and urothelial carcinoma. Activating mutations in FGFRs are also found in multiple forms of pediatric skeletal dysplasias, including achondroplasia, which affects up to one out of every 15,000 live births.

A Phase 3 study comparing infigratinib to standard of care chemotherapy for first line cholangiocarcinoma has been initiated by QED Therapeutics.

Full poster available at: www.QEDTx.com/ESMO2018/

About QED Therapeutics 
QED Therapeutics, a subsidiary of BridgeBio Pharma, is a biotechnology company focused on precision medicine for FGFR-driven diseases. Our lead investigational candidate is infigratinib, an orally administered FGFR1-3 tyrosine kinase inhibitor that has shown meaningful clinical activity in patients with chemotherapy-refractory cholangiocarcinoma with FGFR2 fusions and advanced urothelial carcinoma with FGFR3 genomic alterations. QED is also evaluating infigratinib in preclinical studies for the treatment of achondroplasia and other skeletal dysplasias. We plan to conduct further clinical trials to evaluate infigratinib in additional FGFR-driven tumor types and rare disorders.

PellePharm Presents Updated Data from Two Phase 2 Studies Demonstrating the Potential of Patidegib Topical Gel to Treat Basal Cell Carcinomas in Patients with Gorlin Syndrome and Patients with Non-Gorlin Sporadic BCCs

SAN FRANCISCO–(BUSINESS WIRE)–PellePharm, a late clinical-stage biopharmaceutical company committed to targeting rare skin conditions at their source, today presented updated clinical data from two Phase 2 studies of patidegib topical gel in a poster session at NORD’s Rare Diseases and Orphan Products Breakthrough Summit 2018 in Washington, D.C. Results of the studies showed clinical clearance and prevention of basal cell carcinoma (BCC) tumors after 6 months of treatment with patidegib topical gel in patients with Gorlin Syndrome, a rare genetic disease; and both clinical and histologic clearance after 3 months of treatment in patients with sporadic, nodular BCCs.

“We are pleased by these positive results showing the potential of patidegib topical gel in preventing new facial BCCs in patients with Gorlin Syndrome, potentially reducing the number of surgeries and resulting facial scarring that patients experience,” said Sanuj Ravindran, M.D., president and chief executive officer of PellePharm. “Based on these Phase 2 findings, we intend to initiate a randomized, one-year registrational Phase 3 trial of patidegib topical gel at the end of 2018 in patients with Gorlin Syndrome, and we also plan to study patidegib topical gel in non-Gorlin patients with high-frequency BCCs.”

Title: Hedgehog Inhibition by Topical Patidegib Reduces Facial BCC Burden in Patients with Gorlin Syndrome
Date and Time: Monday, October 15 – Tuesday, October 16, 2018
Poster Number: #71

The data presented at the NORD Summit are from two Phase 2 trials of topical patidegib gel – a randomized, double-blind, placebo-controlled, study in patients with Gorlin Syndrome in the UK and in a study in patients with sporadic, nodular BCCs in the US. In the Gorlin Phase 2 trial, 17 patients with a total of 85 surgically eligible BCCs (SEBs) applied patidegib topical gel (administered in strengths of 2% and 4%) or a topical vehicle control twice daily for 6 months to their face for prevention and to 5 SEBs for treatment.

The Phase 2 Gorlin trial showed that for prevention of surgically-eligible BCCs (SEBs), patients in the topical control group developed an average of 1.4 new SEBs in 6 months. In contrast, patients treated with patidegib topical gel 2% and 4% developed only 0.4 SEBs in Intent to Treat analysis (p=0.096) and only 0.3 SEBs in Per-Protocol analysis (p=0.008). Additionally, clinical clearance of tumors was observed in 27% (12 out of 45 SEBs) of the patidegib topical gel treated subjects compared to no tumors with clinical clearance in subjects in the vehicle group (N=16 SEBs, P=0.02).

In the U.S. trial, 36 non-Gorlin patients with sporadic, nodular BCCs applied patidegib topical gel 2%, 4%, or topical control to BCCs for 3 months. Use of patidegib topical gel 2% was significantly more effective in clinical and histologic clearance of BCCs after 3 months compared with the topical vehicle gel (p=0.045). This finding correlated with a decrease in hedgehog biomarker in BCC tumors after three months in patients using patidegib topical gel.

Across both studies, patients using topical patidegib gel did not experience any of the significant side effects characteristic of oral hedgehog inhibitors (e.g., hair loss, taste loss or frequent muscle cramps). Patients treated with patidegib topical gel 4% experienced mild skin irritation (e.g., redness, itching and swelling), but those using patidegib topical gel 2% did not.

About Patidegib

Patidegib topical gel has shown early promise in a Phase 2 clinical study for the mitigation of BCC tumors in Gorlin Syndrome by blocking the disease at its source within the hedgehog signaling pathway. Topical patidegib gel was developed to provide the efficacy previously demonstrated by oral patidegib in Phase 1 trials without the adverse systemic side effects. Patidegib’s gel formulation is stable at room temperature for at least two years, making it a viable potential therapy for ongoing, at-home management of Gorlin Syndrome. Patidegib has received both Orphan Drug Designation and Breakthrough Therapy Designation from the FDA.

About Gorlin Syndrome

Gorlin Syndrome is a rare, genetic, disease where patients are born with mutations in the tumor suppressor gene encoding PATCHED1 (PTCH1), which acts as the primary inhibitor of the hedgehog signaling pathway. This leads to the formation of multiple basal cell carcinomas, often on the face.

With no FDA-approved drugs available for Gorlin Syndrome BCCs, the standard of care is surgery. People with severe Gorlin Syndrome may have as many as 30 surgeries per year, which can be repetitive, scarring and disfiguring. Approximately 10,000 people in the United States, or one in 31,000, are believed to be affected by Gorlin Syndrome. Gorlin Syndrome is known by several names, including Gorlin-Goltz Syndrome, Basal Cell Nevus Syndrome (BCNS), and Nevoid Basal Cell Carcinoma Syndrome (NBCCS).

About High-Frequency Basal Cell Carcinoma (BCCs)

High-Frequency BCC, like Gorlin Syndrome, is a rare disease which is characterized by the development of an abnormally high number of BCCs. Unlike patients with Gorlin Syndrome, patients with high-frequency BCC are not born with a germline PTCH1 mutation and do not suffer from the other systemic manifestations of Gorlin Syndrome. The standard of care for patients with high-frequency BCC is surgery.

About PellePharm

Founded by world leaders in hedgehog pathway signaling, PellePharm is a biotechnology company committed to targeting rare, genetic skin diseases, including Gorlin Syndrome and High-Frequency Basal Cell Carcinomas (BCCs), at their source. PellePharm’s mission is to improve the quality of life for those suffering from Gorlin Syndrome and High-Frequency BCCs by providing an easy-to-use topical gel that eliminates the need for regular, painful surgeries. Patidegib topical gel is a first-in-class topical formulation of a proprietary hedgehog inhibitor.

Contacts

W2O Group
Peter Duckler, 310-774-3425
pduckler@w2ogroup.com

Eidos Therapeutics to Present Phase 2 Data for AG10 in TTR Amyloidosis Cardiomyopathy at the AHA 2018 Scientific Sessions in a Late-Breaking Featured Science Oral Presentation

SAN FRANCISCO, Oct. 05, 2018 (GLOBE NEWSWIRE) — Eidos Therapeutics, Inc. (Eidos) (Nasdaq:EIDX), today announced that results of its Phase 2 clinical trial studying AG10 in subjects with symptomatic transthyretin (TTR) amyloidosis cardiomyopathy (ATTR-CM) will be announced in a late-breaking featured science oral presentation at this year’s American Heart Association (AHA) Scientific Sessions.

Daniel Judge, M.D., professor in the division of cardiology at the Medical University of South Carolina, will discuss the data in a presentation entitled “Safety, Tolerability and Transthyretin Stabilization by AG10: A Phase 2, Randomized, Double-blind, Placebo-controlled Clinical Trial in Patients with Transthyretin Amyloid Cardiomyopathy and NYHA Class II/III Heart Failure” as part of the New Trials in Cardiovascular Care oral session at 9:00 AM CT on November 10, 2018.

Eidos will host an investor conference call and webcast following the presentation to highlight details of the Phase 2 data. Details for the call and webcast will be announced at a later date.

About AG10

AG10 is an investigational, orally-administered small molecule designed to potently stabilize tetrameric transthyretin, or TTR, thereby halting at its outset the series of molecular events that give rise to amyloidosis, or ATTR. AG10 is currently being examined in an open-label extension of a Phase 2 clinical trial in patients with ATTR cardiomyopathy.

AG10 was designed to mimic a naturally-occurring variant of the TTR gene (T119M) that is considered a “rescue mutation” because it has been shown to prevent ATTR in individuals carrying pathogenic, or disease-causing, mutations in the TTR gene. To our knowledge, AG10 is the only TTR stabilizer in development that has been observed to mimic the “super-stabilizing” properties of this rescue mutation.

About Eidos Therapeutics

Eidos Therapeutics is a clinical stage biopharmaceutical company focused on addressing the large and growing unmet need in diseases caused by transthyretin (TTR) amyloidosis (ATTR). For more information, please visit www.eidostx.com.

Media Contact:
Carolyn Hawley
Canale Communications 619-849-5382
Carolyn@canalecomm.com
Investor Contact:
Alex Gray
Burns McClellan 212-213-0006
agray@burnsmc.com

FDA Grants Orphan Drug Designation to Eidos Therapeutics’ Product Candidate, AG10, for Treatment of Transthyretin Amyloidosis

SAN FRANCISCO, Oct. 03, 2018 (GLOBE NEWSWIRE) — Eidos Therapeutics, Inc. (Eidos) (Nasdaq:EIDX), a clinical stage biopharmaceutical company focused on addressing the large and growing unmet need in diseases caused by transthyretin (TTR) amyloidosis (ATTR), announced today that the U.S. Food and Drug Administration (FDA) has granted the company Orphan Drug Designation for AG10 for the treatment of ATTR.

TTR normally circulates in the blood as a four-part molecule or tetramer, but in ATTR the tetramer destabilizes and dissociates into individual monomers which aggregate as amyloid fibrils. AG10, Eidos’ lead product candidate, is designed to target ATTR at its source by stabilizing tetrameric TTR in the blood. Eidos is investigating AG10 for the treatment of ATTR cardiomyopathy (ATTR-CM) and ATTR polyneuropathy (ATTR-PN), both of which are progressive, fatal diseases. The company plans to initiate Phase 3 studies in each indication in the first half of 2019.

“The granting of Orphan Drug status to Eidos’ lead development candidate, AG10, for treating transthyretin amyloidosis is an important step forward for the product and our company,” said Jonathan Fox, M.D., Ph.D., president and chief medical officer of Eidos. “We believe that AG10 holds great promise as a disease-modifying therapy for patients with ATTR, and Orphan status will help us develop it as quickly as possible.”

Orphan Drug Designation provides incentives and support for the development of drugs for patients with rare diseases, specifically to drugs that are intended for the treatment of diseases or conditions that affect fewer than 200,000 people in the United States. Orphan Drug Designation provides certain benefits, including seven years of market exclusivity upon regulatory approval, exemption from FDA application user fees and tax credits for qualified clinical trial expenses.

About AG10

AG10 is an investigational, orally-administered small molecule designed to potently stabilize tetrameric transthyretin, or TTR, thereby halting at its outset the series of molecular events that give rise to amyloidosis, or ATTR. AG10 is currently being examined in a Phase 2 clinical trial in patients with ATTR cardiomyopathy. Top-line results from this trial are expected to be reported by the end of 2018.

AG10 was designed to mimic a naturally-occurring variant of the TTR gene (T119M) that is considered a “rescue mutation” because it has been shown to prevent ATTR in individuals carrying pathogenic, or disease-causing, mutations in the TTR gene. To our knowledge, AG10 is the only TTR stabilizer in development that has been observed to mimic the “super-stabilizing” properties of this rescue mutation.

About Eidos Therapeutics

Eidos Therapeutics is a clinical stage biopharmaceutical company focused on addressing the large and growing unmet need in diseases caused by transthyretin (TTR) amyloidosis (ATTR). For more information, please visit www.eidostx.com.

Forward-Looking Statements

This release includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act. All statements other than statements of historical facts, including the statements about the clinical and therapeutic potential and future clinical milestones of AG10, including the initiation of Phase 3 clinical trials, the potential for AG10 to capture any expected benefits from Orphan Drug Designation, the indications we intend to pursue and our possible clinical or other business strategies, and the timing of these events, are forward- looking statements. Forward-looking statements can be identified by terms such as “believes,” “expects,” “plans,” “potential,” “would” or similar expressions and the negative of those terms. These forward-looking statements are based on our management’s current beliefs and assumptions about future events and on information currently available to management.

Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These risks include, but are not limited to, risks and uncertainties related to: our limited operating history and historical losses, our liquidity to fund the development of our other product candidates through current and future milestones, our ability to raise additional funding to complete the development and any commercialization of our product candidates, our dependence on the success of our lead product candidate, AG10, results from our clinical trials and pre-clinical studies and those of third parties working in the same area as our product candidate and our dependence on third parties in connection with our manufacturing, clinical trials and pre-clinical studies. Additional risks and uncertainties that could affect our future results are included in the section titled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2018, which is available on the SEC’s website at www.sec.gov and our website at eidostx.com. Additional information on potential risks will be made available in other filings that we make from time to time with the SEC. In addition, any forward-looking statements contained in this press release are based on assumptions that we believe to be reasonable as of this date. Except as required by law, we assume no obligation to update these forward-looking statements, or to update the reasons if actual results differ materially from those anticipated in the forward-looking statements.

Media Contact:

Carolyn Hawley, Canale Communications, (619) 849-5382, carolyn@canalecomm.com

Investor Contact:

Alex Gray, Burns McClellan, (212) 213-0006, agray@burnsmc.com

Eidos Therapeutics Presents Data from its Phase 1 Clinical Trial of AG10 at the 22nd Annual Scientific Meeting of the Heart Failure Society of America

SAN FRANCISCO, Sept. 17, 2018 (GLOBE NEWSWIRE) — Eidos Therapeutics, Inc. (Eidos) (Nasdaq:EIDX) announced the presentation of results from its Phase 1 clinical trial of AG10 during a poster session at the 22nd Annual Scientific Meeting of the Heart Failure Society of America (HFSA). The poster, entitled “AG10, A Novel, Potent, and Selective Transthyretin Stabilizer, Is Well-Tolerated at Doses Resulting in Target Therapeutic Blood Levels, and Demonstrates Clinical Proof-of-Concept in Healthy Volunteers,” was presented on Saturday, September 15, and is accessible through the science section of the company’s website.

In this initial Phase 1 study in healthy adult volunteers, AG10 was well-tolerated with no safety signals of potential clinical concern identified. At the highest tested dose, AG10 achieved 100% transthyretin (TTR) stabilization at peak concentration and over 95% TTR stabilization on average at steady state. Serum TTR concentrations, an in vivo indicator of TTR stability, were increased to a greater degree in AG10-treated patients than placebo-treated patients from baseline to Day 12.

“We believe that maximizing the level of TTR stabilization will lead to optimal clinical benefit for TTR Amyloidosis (ATTR) patients. This initial human trial demonstrated that AG10 stabilized TTR in established ex vivo assays and increased circulating TTR concentrations,” noted Jonathan C. Fox, M.D., Ph.D., president and chief medical officer of Eidos. “Given that below normal levels of serum TTR are associated with poorer prognosis in ATTR patients, and stabilization of TTR by protective mutations or small molecule stabilizers increase serum TTR concentrations, we believe that these data provide clinical proof of concept. We are rapidly moving forward with additional studies of AG10 and have already completed enrollment in our Phase 2 trial in patients with symptomatic ATTR cardiomyopathy (ATTR-CM).”

TTR normally circulates in the blood as a four-part molecule, or tetramer. In ATTR, the tetramer is destabilized by inherited mutation or age-related factors and dissociates into individual monomers, which can aggregate and are deposited as amyloid fibrils in various tissues. AG10, Eidos’ lead product candidate, is designed to target ATTR at its source by stabilizing tetrameric TTR in the blood. Eidos is pursuing AG10 for the treatment of ATTR-CM and ATTR polyneuropathy (ATTR-PN), both of which are progressive, fatal diseases. The company plans to initiate Phase 3 studies in each indication in the first half of 2019.

About AG10

AG10 is an orally-administered small molecule designed to potently stabilize tetrameric transthyretin, or TTR, thereby halting at its outset the series of molecular events that give rise to transthyretin amyloidosis, or ATTR. AG10 is currently being tested in a Phase 2 clinical trial in patients with symptomatic ATTR cardiomyopathy. Top-line results from this trial are expected to be reported in the fourth quarter of 2018.

AG10 was designed to mimic a naturally-occurring variant of the TTR gene (T119M) that is considered a “rescue mutation” because it has been shown to prevent ATTR in individuals carrying pathogenic, or disease-causing, mutations in the TTR gene. To our knowledge, AG10 is the only TTR stabilizer in development that has been observed to mimic the “super-stabilizing” properties of this rescue mutation.

About Eidos Therapeutics

Eidos Therapeutics is a clinical stage biopharmaceutical company focused on addressing the large and growing unmet need in diseases caused by transthyretin (TTR) amyloidosis (ATTR). For more information, please visit www.eidostx.com.

Forward-Looking Statements

This release includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act. All statements other than statements of historical facts, including the statements about future clinical milestones of AG10, including the completion of our ongoing Phase 2 clinical trial and availability of top-line data therefrom, the initiation of Phase 3 clinical trials, the timing of these events, the indications we intend to pursue and our possible clinical or other business strategies, are forward-looking statements. Forward-looking statements can be identified by terms such as “believes,” “expects,” “plans,” “potential,” “would” or similar expressions and the negative of those terms.

These forward-looking statements are based on our management’s current beliefs and assumptions about future events and on information currently available to management.

Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These risks include, but are not limited to, risks and uncertainties related to: our limited operating history and historical losses, our liquidity to fund the development of our other product candidates through current and future milestones, our ability to raise additional funding to complete the development and any commercialization of our product candidates, our dependence on the success of our lead product candidate, AG10, results from our clinical trials and pre-clinical studies and those of third parties working in the same area as our product candidate and our dependence on third parties in connection with our manufacturing, clinical trials and pre-clinical studies. Additional risks and uncertainties that could affect our future results are included in the section titled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in the final

prospectus for our initial public offering filed with the SEC on June 21, 2018, and our Quarterly Report on Form 10-Q for the quarter ended June 30, 2018, which are available on the SEC’s website at www.sec.gov and our website at eidostx.com. Additional information on potential risks will be made available in other filings that we make from time to time with the SEC. In addition, any forward-looking statements contained in this press release are based on assumptions that we believe to be reasonable as of this date. Except as required by law, we assume no obligation to update these forward- looking statements, or to update the reasons if actual results differ materially from those anticipated in the forward-looking statements.

Media Contact:

Carolyn Hawley, Canale Communications, (619) 849-5382, carolyn@canalecomm.com

For Investors

Alex Gray, Burns McClellan, (212) 213-0006, agray@burnsmc.com