v3.22.2.2
Cover Page - USD ($)
$ in Millions
 12 Months Ended
Jun. 30, 2022
Sep. 07, 2022
Dec. 31, 2021
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Jun. 30, 2022    
Document Fiscal Year Focus 2022    
Document Fiscal Period Focus FY    
Entity File Number 000-50484    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 51-0407811    
Entity Address, Address Line One 11455 El Camino Real    
Entity Address, City or Town San Diego    
Entity Address, Postal Zip Code 92130    
City Area Code 858    
Local Phone Number 369-7100    
Trading Symbol MEIP    
Entity Registrant Name MEI Pharma, Inc.    
Entity Central Index Key 0001262104    
Current Fiscal Year End Date --06-30    
Entity Filer Category Non-accelerated Filer    
Entity Current Reporting Status Yes    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Small Business true    
Title of 12(b) Security Common Stock, $0.00000002 par value    
Security Exchange Name NASDAQ    
Entity Interactive Data Current Yes    
Entity Address, State or Province CA    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
ICFR Auditor Attestation Flag false    
Entity Common Stock, Shares Outstanding   133,260,865  
Entity Public Float     $ 353.2
Documents Incorporated by Reference

Certain information required by Part III of this Annual Report on Form 10-K is incorporated by reference from the registrant’s definitive proxy statement for the annual meeting of stockholders to be held in December 2022, which will be filed with the Securities and Exchange Commission within 120 days after the close of the registrant’s fiscal year ended June 30, 2022.

    
Auditor Firm ID 243    
Auditor Location San Diego, California    
Auditor Name BDO USA, LLP