The Intellectual Property Office of Singapore (IPOS) recently set a higher bar for allowance of post-grant amendments (circular available here).
Consequently, post-grant amendments may not be allowed if:
i) a full disclosure of all relevant matters in relation to the proposed amendments was not provided by the patentee
ii) there was an unreasonable delay in seeking the amendments, or
iii) an unfair advantage was obtained by delaying the amendments which the patentee knew to be needed.
The above requirements are additional to previous practice which dictated that amendments:
iv) do not introduce additional matter, and
v) do not extend the scope of protection.
The change in practice follows decisions in Ship's Equipment Centre Bremen GmbH v Fuji Trading (Singapore) Pty Ltd & Ors  SGHC 159 and more recently Warner-Lambert Company LLC v Novartis (Singapore) Pte Ltd  SGHC 106 where the Singapore High Court affirmed the guidelines for allowance of post-grant amendments set down in the UK.
The above criteria will apply to all pending and new requests for post-grant amendments. Accordingly, patentees aware of prior art that is likely to affect their patent’s validity may wish to consider promptly applying for leave to amend their patent specification. Those with pending applications should consider addressing prior art which would impact the scope of their pending Singapore claims prior to grant stage.