2023-04-18 12:00:51 ET
Summary
- Catalyst Pharmaceuticals, Inc. filed a lawsuit against Teva Pharmaceutical Industries Limited's ANDA.
- At the heart of the situation is a patent that should never have been granted.
- While courts have not addressed this, instead focusing on orphan drug exclusivity and other issues, it all depends on a particular case.
In my last coverage , I discussed Teva Pharmaceutical Industries Limited's ( TEVA ) generic ANDA challenge to Catalyst Pharmaceuticals, Inc.'s ( CPRX ) Firdapse, and the history behind Firdapse. As a biopharma investor, I like that Catalyst Pharma stock is up 600% in the last 5 years, but as a patient advocate I deplore their tactics of adding a simple phosphate linker to a well-known, inexpensive and life-saving drug, and charging $375,000 for the "new" concoction.
A family-run operation called Jacobus did the basic pharmacy work required to put the drug's ingredients together, and sold it at a low price to Lambert-Eaton Myasthenic Syndrome ((LEMS)) patients under a compassionate use program. Some 200 of the estimated 1500 U.S. LEMS patients received the drug. After the FDA approved firdapse, Jacobus managed to get its original drug, ruzurgi, approved in a pediatric setting. However, the approval was reversed after Catalyst sued and a Florida court called it "egregious." Then, Teva filed an ANDA in January, and Catalyst filed suit on March 1. This is the backstory.
On March 1, Catalyst filed suit against Teva in New Jersey District Court. Catalyst alleges that Teva's ANDA, if approved, will infringe on a set of patents (the patent suit) as follows - one or more of United States Patent Nos. 10,626,088 ("the '088 patent), 10,793,893 ("the '893 patent"), 11,060,128 ("the '128A patent"), 11,268,128 ("the '128B patent"), 11,274,331 ("the '331 patent"), and 11,274,332 ("the '332 patent")).
In the complaint , Catalyst says Amifampridine is also known as 3,4-diaminopyridine or 3,4-DAP. Then it says it "holds New Drug Application ("NDA") No. 208078 for the use of amifampridine tablets, which it sells under the trade name Firdapse." However, in a 2018 FDA document , there's some difference in language:
Subject: Product name: Amifampridine phosphate (3,4-diaminopyridine phosphate) NDA: 211230 Trade Name, dosages, formulations, routes: Firdapse is formulated as 10 mg oral tablets. A single dose is not to exceed 20 mg. The recommended starting dose is with a maximum of 80 mg/day, in divided doses 3 to 4 times per day. IND Number: 106263 Indication(s): treatment of Lambert-Eaton myasthenic syndrome ((LEMS)) in adult patients Sponsor: Catalyst Pharmaceuticals, Inc. PDUFA Goal Date: November 28, 2018
So, on the one hand, Catalyst says Firdapse is 3,4-DAP, on the other hand, it (or the FDA here) says that Firdapse is what is known as 3,4-DAPP, with an extra P standing for the phosphate linker. The two are not the same.
If you look into the history of Amifampridine, this was discovered in the 1970s, originally as 3,4-DAP. After Swedish scientists discovered its therapeutic effect on LEMS, it was sold in this formulation for a very low price, and in the U.S., the pharmacy work was done by Jacobus, who opted not to commercialize it in a big way, so the tablets sold for about a dollar a pill. A French hospital added the phosphate, patented that version (this is where it probably shouldn't have been allowed), and sold the rights to a company, whence it came into the hands of BioMarin (BMRN), from whom Catalyst acquired U.S. rights. So, the version for which they got U.S. rights - is it 3,4-DAP or 3,4-DAPP? Purely by looking at the history, it appears to be 3,4-DAPP. Does ownership of 3,4-DAPP give one rights to 3,4-DAP? I don't know, but I would certainly doubt it.
Catalyst's principle moral argument, presented in their response to an editorial published a few years ago, is that the significant investment they made in running multiple trials on their version of 3,4-DAP was geared towards making their version of 3,4-DAP accessible to more patients than the only 200 or so who received the medicine from Jacobus through the compassionate use program. Here's what they said:
Currently, we estimate that a small fraction of LEMS patients receive 3,4-DAP and only through the cumbersome process of compassionate use programs. Many physicians believe that 3,4-DAP is the most effective treatment for patients with LEMS. 1 Catalyst believes that perpetuating a system that provides access to so few patients is morally wrong, because it leaves most LEMS patients without treatment. The road to FDA approval requires a great deal of resources, but we at Catalyst consider this worthwhile. If we are able to gain FDA approval, it will greatly increase the number of LEMS patients who have access to Firdapse.
On the one hand, this is indeed true. The approval gave it much wider access. However, going by this argument alone, it can be argued that Teva's generic version of 3,4-DAP will reach even more patients because it will be less expensive. An argument from a moral need to expand access will not help a profit-making venture; expanded access can be a byproduct of approval, but cannot be its sole motivator - which it surely is not if the company is charging $375,000 for the drug.
The core question will again become this: whether the novelty of adding a phosphate linker to a widely used molecule is a patent that is enforceable. Catalyst Pharmaceuticals, Inc. stock went down on the ANDA news because, like me, investors are aware that, like much of the legal process, it all depends on a specific judge. Court opinions are extremely subjective, or there wouldn't be a reversal and appeals process for them. Everything will now depend on which judge takes up the lawsuit and how the process proceeds.
For further details see:
Catalyst Pharma And Teva's ANDA Challenge: Firdapse Hangs By A Thread