On 3 October 2024, the US Patent Trial and Appeal Board (PTAB) instituted inter partes review (IPR) of Johns Hopkins University’s US patent no. 11,643,462 in IPR2024-00648. MSD filed a petition on 13 March 2024, challenging the validity of the patent, which is directed to a method for treating, with pembrolizumab, cancer patients having a tumour that is microsatellite instability high (MSI-H) or DNA mismatch repair (MMR) deficient.
This followed the institution of eight IPRs in relation to Johns Hopkins University (JHU) patents relating to pembrolizumab on:
- 27 September 2024 (US patent numbers: 11,649,287 (IPR2024-00647), 11,629,187 (IPR2024-00649), and 11,634,491 (IPR2024-00650)). The petitions for each of these were filed on 13 March 2024;
- 23 September 2024 (US patent numbers 10,934,356 (IPR2024-00622), 11,325,974 (IPR2024-00623), 11,325,975 (IPR2024-00624) and 11,339,219 (IPR2024-00625)). The petitions for these IPRs were filed by MSD on 4 March 2024; and
- 13 June 2024 (US patent number 11,591,393 (IPR2024-240)). The petition for this IPR was filed on 30 November 2011.
In each case, the PTAB determined that MSD had demonstrated there was a “reasonable likelihood that the petition would prevail in showing that at least one challenged claim is unpatentable”.
In November 2022 MSD filed a complaint in the United States District Court (District of Maryland) against JHU seeking declarations of breach of contract, non-infringement and promissory estoppel. JHU filed a counter-claim on 12 April 2023, including alleging infringement of each of the patents subject to the IPR proceedings referred to above.
The US Court proceeding has been stayed pending the outcome of IPR2024-240. No trial date has been scheduled.
MSD’s Keytruda® (pembrolizumab) is approved in the US (alone or in combination with other agents) for numerous indications including in relation to endometrial carcinoma, Stage 111-IVA cervical cancer, urothelial carcinoma, gastric/gastroesophageal junction adenocarcinoma, and biliary tract cancer.