Facts:

The Sugen Inc., Pfizer Inc., and Pfizer Products India Pvt. Ltd. (Plaintiffs) had filed a suit against NATCO Pharma Ltd. and its President (Research & Development) & Additional Director Mr. A. Rao (defendants), seeking an injunction from making, selling, distributing, advertising, or exporting any product infringing Indian Patent No. 209251 i.e. “SUTENT,” used to treat gastrointestinal stromal tumors and advanced renal cell carcinoma.

Background/ Procedural Posture:

Patent Controller & Designs:

The patent was initially revoked on September 24, 2012, after a post-grant opposition by M/s Cipla Ltd.

Delhi High Court:

• An ex parte ad-interim order on June 22, 2012, restrained the Defendants from infringing the patent.
• The Defendants contested the suit by filing a written statement, and Defendant No. 2 also filed a counterclaim for revocation of the patent.
• After the patent's initial revocation, the Plaintiffs challenged the decision, leading to an interim order on October 8, 2012, against M/s Cipla Ltd., which was dismissed on October 12, 2012.
• The ex parte order was kept in abeyance on November 9, 2012, pending the outcome of proceedings before the Supreme Court.Following the Supreme Court's decision, the ex parte order was restored on December 10, 2012.
• The patent was revoked again on February 11, 2013. The court considered revoking the ex parte order due to the patent's revocation and adjourned the matter to February 21, then to February 28, 2013.

Supreme Court:

Granted the SLPs, converting them into Civil Appeals No.8479-8480/2012, and disposed of them on November 27, 2012, setting aside the Assistant Controller's revocation order for violating principles of natural justice and remanded the matter for a fresh decision.

(Paragraphs 2 to 9)

Main Issue:

Whether a patent is enforceable if it is revoked but remains on the register?