XML 41 R1.htm IDEA: XBRL DOCUMENT v3.21.1
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Mar. 26, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Entity Interactive Data Current Yes    
Document Period End Date Dec. 31, 2020    
Document Fiscal Year Focus 2020    
Current Fiscal Year End Date --12-31    
Document Fiscal Period Focus FY    
Entity Registrant Name PHATHOM PHARMACEUTICALS, INC.    
Entity Central Index Key 0001783183    
Entity Tax Identification Number 82-4151574    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer No    
Entity Filer Category Non-accelerated Filer    
Entity File Number 001-39094    
Entity Shell Company false    
Entity Emerging Growth Company true    
Entity Ex Transition Period true    
Entity Small Business true    
ICFR Auditor Attestation Flag false    
Entity Incorporation, State or Country Code DE    
Entity Address, Address Line One 100 Campus Drive    
Entity Address, Address Line Two Suite 102    
Entity Address, City or Town Florham Park    
Entity Address, State or Province NJ    
Entity Address, Postal Zip Code 07932    
City Area Code 877    
Local Phone Number 742-8466    
Entity Common Stock, Shares Outstanding   31,321,613  
Entity Public Float     $ 552.3
Title of 12(b) Security Common Stock, par value $0.0001 per share    
Trading Symbol PHAT    
Security Exchange Name NASDAQ    
Documents Incorporated by Reference

Certain sections of the registrant’s definitive proxy statement for the 2021 annual meeting of stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.