There has been lots of U.S. Supreme Court action in patent law in the last 16 years (30 major cases are recited below, with one additional important case currently pending), which has collectively mostly weakened patent law, with some exceptions.
There has been little major patent legislation since 2011 when the American Invents Act, which was the last major overhaul of U.S. statutory patent law was adopted. The AIA eliminated tax strategy patents (a case to resolve the issue had been pending when the legislative fix arrived).
A background report for Congress from the Congressional research service on patent law and procedure can be foundhere.
A major case deciding the constitutionality of part of the AIA and the remedy if it is unconstitutional is pending in Arthrex which has had oral arguments but not decision on the merits yet.
* Thryv, Inc. v. Click-to-Call Technologies, LP (2020) (7-2), the Court disagreed with the Federal Circuit and held that the PTAB’s decision on whether a petition for inter partes review is timely is not judicially reviewable replying on Cuozzo Speed Technologies, LLC v. Lee, 136 S. Ct. 2131 (2016).
* SAS Institute, Inc. v. Iancu (2018), the United States Supreme Court decided an important aspect of procedure in IPR cases holding that once an inter partes review is instituted by the Director of the USPTO, the PTAB must decide the patentability of all of the claims challenged.
* Sandoz Inc. v. Amgen Inc. (2017), the U.S. Supreme Court rebuffs the Federal Circuit on a patent law issue related to patent claims in products (basically drugs) biologically similar to products subject to an existing patent making it harder to "puppy guard" such a patent.
* Impressions Products, Inc. v. Lexmark Int'l, Inc. (2017), Reversing the Federal Circuit to weaken the rights of patent holders, the U.S. Supreme Court held that the first sale doctrine terminates all patent rights in an item, both in the case of sales in the U.S. and sales outside the U.S., even if the contract of sale purports to reserve patent rights in that particular item produces using the patent.
* TC Heartland LLC v. Kraft Foods Group Brands LLC (2017), In 1990, the Federal Circuit held that due to an amendment to the general venue statute that patent lawsuits could be brought in any district that has personal jurisdiction over the defendant. This gave rise to extreme forum shopping by patent trolls with the Eastern District of Texas arising as a very plaintiff friendly venue in which many patent infringement cases were brought, despite it having only minimal contacts with the patent holder. This 8-0 decision overrules the 1990 decision of the Federal Circuit and holds that the 1957 decision of the U.S. Supreme Court that patent lawsuits may be brought only in the state where a defendant is incorporated remains good law.
* SCA Hygiene Products Aktiebolag v. First Quality Baby Products, LLC (2017), the equitable doctrine of laches cannot be used to bar the recovery of patent infringement damages incurred within the six year statute of limitations; this follows another recent ruling that laches does not bar the recovery of damages for patent infringement incurred within the three year statute of limitations.
* Samsung Electronics Co. v. Apple, Inc. (2016), in the case of a multicomponent product, the relevant “article of manufacture” for arriving at a [35 U.S.C.] §289 damages award need not be the end product sold to the consumer but may be only a component of that product.
* Limelight Networks v. Akamai Technologies (2014), liability for inducing infringement could not exist when there was no direct infringement (the conduct in question involved part of a patented process being carried out by one party, who allegedly urged customers to carry out the balance of the patented process themselves, so that no one person infringed)
* Nautilus v. Biosig Instruments (2014), the Court rebuked a standard for what kind of patent description was excessively vague that was absurdly indulgent to the patent applicant.
* Alice v. CLS Bank, Int'l. (2014), prohibited software that generically applied an abstract idea that is not otherwise patentable, have made it dramatically more difficult to obtain patents, particularly the subset of patents called "business method patents" which include most software patents. In January of 2004, only a little more than 2% of patent applications were rejected (on Section 101 grounds which governs what is patentable). By July of 2015, that percentage is about 15%.
Before Alice in July of 2014, about 31% of business method patent applications were rejected on Section 101 grounds (already a major increase from 2007 when the U.S. Supreme Court adopted a more expensive definition of "obviousness" under Section 101 for patent law purposes in KSR International v. Teleflex (see below), and 2010 when the U.S. Supreme Court in Bilski v. Kappos (see below) articulated a new (and functionally more restrictive) legal standard for granting software patents (although not as restrictive as the federal circuit case it reviewed which is linked), while affirming that software patents could still be obtained). After Alice, 82% of business method patent applications were rejected.
* Octane Fitness, LLC v. Icon Health & Fitness, Inc. (2014) (unanimous) and Highmark Inc. v. Allcare Management Systems (2014) (unanimous) (the Federal Circuit had set too high a standard for the recovery of attorneys' fees for frivolous patent prosecutions)
* Medtronic v. Mirowski (2014) (unanimous) (burden of proof wrongly placed on someone other than the patent holder)
* Association for Molecular Pathology v. Myriad Genetics (2013) (unanimous) (invalidated patents on naturally occurring DNA sequences)
* Gunn v. Minton (2013) (unanimous) (overruling Federal Circuit precedents which had held that federal courts have broad jurisdiction over claims of malpractice in attorney malpractice cases where the underlying malpractice involved patent law, while reviewing a Texas Supreme Court ruling)
* Mayo Collaborative Services v. Prometheus Laboratories, Inc. (2012) (unanimous) (district court's factual findings made clear that drug monitoring device patent merely restated a law of nature and was invalid)
* Caraco v. Novo (2012) (unanimous) (alleged infringers right to bring counterclaims expanded)
* Bowman v. Monsanto Co. (2012) (unanimous) (first sale doctrine does not invalidate ban on reproducing crops grown with patented GMO seeds)
* Kappos v. Hyatt (2012) (unanimous)(expanding ability of applicant denied a patent to challenge the denial with additional evidence)
* Microsoft Corp. v. i4i Ltd. Partnership (2011) (unanimous) (presumption of validity of patent continues to apply during patent re-examination process conducted by PTO).
* Stanford v. Roche (2011) (a case over who is entitled to a patent between two potential patent holders)
* Global-Tech v. SEB (2011) (8-1) (added knowledge of infringement element in claim for induced patent infringement)
* Bilski v. Kappos (2009) (unanimous to reverse, complicated holding as to extent of new law) (analysis to determine validity of business method patents tightened, dramatically narrowing their availability)
* Quanta Computer, Inc. v. LG Electronics, Inc. (2008) (unanimous) (disavows Federal Circuit doctrines allowing patent holders to limit use of patented device after a first sale)
* KSR v. Teleflex (2007) (unanimous) (tightened standard for obviousness in order to qualify for patent protection)
* MedImmune v. Genentech (2007) (8-1) (allows for contests of patent validity without risking liability by infringing patent prior to legal ruling on question)
* Microsoft v. AT&T (2007) (7-1) (U.S. patents laws don't have extraterritorial application; U.S. patent law doesn't apply to software copied abroad and not repatriated.)
* eBay Inc. v. MercExchange, L.L.C. (2006) (unanimous) (sets higher standard for obtaining injunctions once infringement is established)
* Merck KGaA v. Integra Lifesciences I, Ltd. (2005) (unanimous) (exemption from patent infringement applies to use of patented drugs for narrow purposes of research associated with FDA drug approval process)