Constitutional Court to hear fight over a cheaper generic of prostate cancer drug Xtandi

Men being treated for advanced prostate cancer, and the families paying for that treatment, are waiting on a court date rather than a new medicine. A three-year legal fight over a cheaper version of the prostate cancer medicine Xtandi is due before the Constitutional Court this month. No hearing date has been published beyond that.

The medicine is enzalutamide. It is used for prostate cancer that no longer responds to hormone therapy or surgery. Japanese drugmaker Astellas sells it as Xtandi under a patent held by the University of California, where it was developed. Eurolab, a Johannesburg generics company, makes a copy called Enzutrix, which Dis-Chem distributes.

The short version: Enzutrix is still registered and still on sale. The fight now is about whether Eurolab owes damages for selling it while the patent dispute was alive, and whether the generic should be stopped.

The price difference families are actually living with

According to Eurolab's court papers, as reported by the Sunday Times, a year's supply of Xtandi costs nearly R361,000. A year of Enzutrix costs R299,407. That is about R60,000 less. For a household without full oncology cover, R60,000 is not a rounding error. It is a year of other bills.

Those figures come from the papers as the Sunday Times reported them on 7 November. They are not a quote from a pharmacy till this morning, and a medical scheme may fund one product, the other, or neither, on its own rules.

How the case reached this month

The South African Health Products Regulatory Authority registered Enzutrix in January 2023. The university and Astellas asked Eurolab to undertake not to sell it for the life of the patent. Eurolab refused. It argued that the university had never been entitled to apply for the South African patent in the first place.

In February 2025 the Commissioner of Patents, sitting in the high court in Pretoria, agreed. The court found the university had not secured assignments from all the inventors before it filed, and revoked the patent.

The Supreme Court of Appeal reversed that on 17 March this year. A majority upheld the university's appeal and reinstated the patent. It refused to order Enzutrix off the shelves while the litigation continued. The court's reasoning was that the harm to the patent holders was financial and could be put right later, while the harm to patients could not.

Judge John Smith put it this way:

"If the sale of Enzutrix were enjoined, the consequences for cancer patients using it would be serious and immediate."

The Cape Times, reporting that judgment, said the patent was due to expire within weeks of that March ruling. This article does not treat that as a fresh expiry date in November. The live question now is damages and whether the generic stays available while the Constitutional Court hears the matter.

What each side is asking for

The university is pursuing a damages claim against Eurolab that runs to millions of rand, the Sunday Times reported on 7 November. The university and Astellas want Eurolab and Dis-Chem stopped from making and distributing the generic.

Eurolab says it will ask the Constitutional Court to find that it did not infringe the patent. If the appeal court's judgment stands, it says in its papers, it "faces potential substantial monetary liability".

The university and Astellas say about $1.5 billion went into developing Xtandi and that a rival should not profit from the invention through a legal technicality. Their papers argue that patents should not be "vulnerable to attack on highly technical grounds" unrelated to the merits of the invention, and warn that foreign inventors may avoid South Africa if Eurolab prevails. Of 11,173 patents filed in the country in 2025, they say, 8,910 came from foreign companies.

Those are arguments about patent law. They are not clinical advice about which pack a man should inject or swallow this week.

What patients should do while the court date is unannounced

Enzutrix remains registered and on sale. Nothing in the appeal court's order removed it. Patients taking Xtandi or Enzutrix should carry on with the treatment their oncologist prescribed. Stopping a cancer medicine because a hearing might be scheduled this month is not what either side's papers ask a patient to do.

Cost is the reason the appeal court kept the generic on the shelves. It described Enzutrix as far cheaper and essential to patients without medical aid. The Sunday Times, citing a published study, put the cost of treating the roughly 11,000 new prostate cancer cases diagnosed in South Africa in 2022 at R2.1 billion. That is a system figure. It does not tell one family what their scheme will pay in 2026.

A man who is unsure which product he is on can ask the oncology unit or the dispensing pharmacy for the name on the label, Xtandi or Enzutrix, and for whether the scheme has authorised that pack. If the Constitutional Court later changes what may be sold, the people who should explain the switch are the oncologist and the scheme, not a headline.

What is still open

No hearing date has been published. The Constitutional Court has not said whether it will hear the appeal this month or only receive the papers. The damages number is described as millions of rand, not a final award. The Sunday Times account of the prices has not been replaced by a newer public tariff in the material this desk used.

The appeal judgment itself, Regents of the University of California and Others v Eurolab (Pty) Ltd and Others [2026] ZASCA 30, was described here from press reports of the order, including the Cape Times, because the judgment text was not available to this desk when the story was written. The order as those reports give it is the one that matters for patients this week: the patent was reinstated, and Enzutrix was not taken off the shelf.

None of this replaces advice from your own clinician. If you or someone you care for is on Xtandi, Enzutrix, or another prostate cancer treatment, speak to the oncologist or the medical scheme before changing anything, especially if a dose has been missed or a bill has suddenly changed.