[2025] FCA 1321
General information, not legal advice.
Federal Court of Australia
2025-10-29
Needham J
Original judgment source is linked above.
ARROTEX PHARMACEUTICALS PTY LTD (ACN 605 552 234)
(a) any judge, employee or other personnel of the Court;
(b) the prospective applicants, including its external legal representatives;
(c) the prospective respondent, including its external legal representatives; and
will not be open to public inspection or disclosed in open Court or disclosed in the
Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.
(a) rule 7.23 is a "beneficial provision, the purpose of which is to enable a person who believes he, she or it may have a right to seek relief to obtain information to make a responsible decision as to whether to commence proceedings" (Allsop CJ at [4]);
(b) the words of the relevant rule, r 7.23(1)(a), are focused on what "may" be the position (Allsop CJ at [8]);
(c) "One must keep the words of the rule firmly in mind in examining the material that exists in order to come to an evaluation as to whether the relevant person reasonably believes that he or she may have a right to relief. That evaluation may well be one about which reasonable minds may differ" (Allsop CJ at [8]);
(d) "... the rule has two features:
- there must be a reasonable belief as to a particular state of affairs; and
- that state of affairs consists of the possibility (required by the word "may") that the prospective applicant has a right to obtain relief from the prospective respondent."
(e) "The following propositions about preliminary discovery applications should be accepted:
(i) the prospective applicant must prove that it has a belief that it may (not does) have a right to relief;
(ii) it must demonstrate that the belief is reasonable, either by reference to material known to the person holding the belief or by other material subsequently placed before the Court;
(iii) the person deposing to the belief need not give evidence of the belief a second time to the extent that additional material is placed before the Court on the issue of the reasonableness of the belief. That belief may be inferred;
(iv) the question of whether the belief is reasonable requires one to ask whether a person apprised of all of the material before the person holding the belief (or subsequently the Court) could reasonably believe that they may have a right to obtain relief; and
(v) it is useful to ask whether the material inclines the mind to that proposition but very important to keep at the forefront of the inclining mind the subjunctive nature of the proposition. One may believe that a person may have a case on certain material without one's mind being in any way inclined to the notion that they do have such a case."
(f) In order to defeat a claim for preliminary discovery, the prospective respondent will need to show, either that the subjectively held belief does not exist (which is not put by the prospective respondent in this case), or, "if it does, that there is no reasonable basis for thinking that there may be (not is) such a case" (Perram J at [121]). That may be done by demonstrating that no reasonable person, faced with the evidence relied on by the prospective applicant, would think that a right to relief might exist: Perram J at [125].
(a) Impurity IIa as the methanesulfonate salt (which is referred to in the Patents as Impurity IIc) strongly inhibits in the micro- and submicro-molar range CYP3A4, CYP2D6, CYP2C19, CYP2C9 (four cytochrome enzymes of the CYP450 system) and HERG currents and is highly cytotoxic, compared with safinamide methanesulfonate (referred to as "Ic" in the Patents) with high purity degree: (see page 4 of the 328 Patent and page 5 of the 778 Patent).
(b) Compounds with strong inhibition of drug-metabolizing enzymes, in particular CYP 450 enzymes, and HERG channel blocking properties have a high probability to be toxic and that their development has to be stopped at an early stage: (see page 4 of the 328 Patent and page 5 of the 778 Patent)
(c) Safinamide and its salts produced using prior art methods contain Impurity IIa, or its methanesulfonate salt IIc, higher than 0.03% by weight, and are therefore unsuitable for safe therapeutical applications: (see page 8 of the 328 Patent and page 10 of the 778 Patent).
(d) Pharmaceutical preparations containing safinamide or its salt where the content of IIa, or its salts is not lower than 0.03%, and preferably not lower than 0.01% by weight, with respect to safinamide or its salt containing Impurity IIc are not suitable as medicaments: (see page 8 of the 328 Patent and page 10 of the 778 Patent).
36. High purity degree safinamide or ralfinamide or a salt thereof with a pharmaceutically acceptable acid with a content of the respective impurity (S)-2-[3-(3- fluorobenzyl)-4-(3-fluorobenzyloxy)benzylamino]propanamide (IIa) [Impurity IIa] or (S)-2-[3-(2-fluorobenzyl)-4-(2-fluorobenzyloxy)benzylamino]propanamide (IIb)
or a salt thereof with a pharmaceutically acceptable acid which is lower than 0.03% (by weight).
37. High purity degree safinamide or ralfinamide salt with a pharmaceutically acceptable acid as in claim 36 wherein the pharmaceutically acceptable acid is methanesulfonic acid and the content of the respective impurity of formula (IIa) or (IIb) as the salt with methanesulfonic acid is lower than 0.01% (by weight).
Safinamide does not appear to significantly induce or inhibit enzymes at clinically relevant systemic concentrations. In vitro metabolism studies have indicated that there is no meaningful induction or inhibition of cytochrome P450, CYP2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2El and 3A3/5 at concentrations which are relevant (Cmax of free safinamide 0.4 μM at 100 mg/day) in man. Dedicated drug-drug interaction studies performed with ketoconazole, L-dopa and CYPlA2 and CYP3A4 substrates (caffeine and midazolam), did not detect any clinically significant effects on the pharmacokinetics of safinamide, or L-dopa, caffeine and midazolam.
(prospective applicants' emphasis added)
(a) There are no studies capable of supporting the statements in the Xadago Product Information extracted in paragraph 31 above, other than studies carried out using high degree purity safinamide (as mesilate) with Impurity IIc lower than 0.03% (by weight).
(b) No clinical information is available regarding the safety or potential drug - drug interactions of any formulation of safinamide other than studies carried out using high degree purity safinamide (as mesilate) with Impurity IIc lower than 0.03% (by weight).
(c) There are no studies capable of supporting the statements in the Xadago Product Information extracted in paragraph 31 above in respect of safinamide (as mesilate) with Impurity IIc higher than 0.03% (by weight).
(a) have the same indications (ie, use for Parkinson's Disease) as Xadago;
(b) were approved as generic versions of Xadago;
(c) will contain the same strengths of safinamide as Xadago; and
(d) are accompanied by Product Information documents which (as noted above) contain the Enzyme Statement in the same terms as the Xadago Product Information document, and thus refer to the same studies in each case.
Having regard to [the matters quoted in [28] above], I would not expect a generic pharmaceutical company to seek approval of a safinamide mesilate medicine with an Impurity Ila level of above 0.03%.
(a) Bioequivalence and bioavailability
(i) Drugs to be sold in Australia must be approved by the TGA by submitting a Common Technical Document and the TGA will then assess them so as to be satisfied that they are "efficacious and safe".
(ii) For new drugs, this must be done through sufficiently large clinical trials. For generic products, "efficacy can alternatively be established through bioequivalence to an originator drug product", with quality and safety still independently considered.
(iii) Bioequivalence can be achieved if products are "pharmaceutically equivalent or pharmaceutical alternatives and their bioavailabilities (rate and extent) after administration in the same molar dose lie within acceptable predefined limits" (see European Medicines Agency, Guideline on the investigation of bioequivalence, (Doc. Ref: CPMP/EWP/QWP/1401/98 Rev. 1/Corr**) (Bioequivalence Guidelines) at [1.1]).
(iv) Bioavailability refers to the amount of active ingredient that becomes available to be absorbed, concentrated in the blood, metabolised and then excreted. Concentration builds up and is absorbed over time, and ideally reaches peak concentration early and stays within the therapeutic range.
(v) In considering whether a drug is bioequivalent, the blood concentration-time parameters "do not need to be identical to the originator drug product, but instead must be within acceptable limits (those limits being noted by the Bioequivalence Guidelines as 80% to 125%).
(b) Pharmaceutical equivalents and alternatives: Pharmaceutical equivalents contain the same active substances in the same dosage forms that meet the same or comparable standards. Pharmaceutical alternatives are products with different salts, esters, ethers (and so on) or which differ in dosage form or strength.
(c) Impurities: The Bioequivalence Guidelines do not require a determination of whether two drug products "have the same, or even similar, levels of impurities". In fact, they do not refer to "impurity" at all. As bioequivalence is focused on the factors set out in (a)(iii) above, Professor Roberts says that "the TGA is not seeking to identify relative similarity in other aspects of formulation".
(d) Safety and quality: To consider safety and quality, the TGA will assess the information in the Common Technical Document modules, and ask any follow-up questions, and "will assess the presence of any impurities against specified and regulatory limits", relevantly the International Conference on Harmonisation Guidelines (ICHG) (ICHG Q3A(2) was tendered as Exhibit 2). The assessment is done as an independent process, not "by comparison to the impurity profile of the originator drug product". Professor Roberts notes the processes by which new drugs are assessed against impurity standards, being the ICHG or, where available, monographs (of which there appear to be none for safinamide). Where a new generic drug product falls outside the standard the ICHG allows, or there is no monograph available, then reference will be made to the originator drug product for a new drug product.
(e) The patents:
(i) Professor Roberts observes that the Relevant Impurity (being IIa) is a "synthesis impurity" which arises during the process of production of the active ingredient. He notes that he understands "high purity degree" safinamide to mean less than 0.03% of the Relevant Impurity. He was asked:
whether the information provided in the Patent [being the 328 Patent]:
(a) provides a basis for the statements on page 8, lines 19 to 31 to the effect that, unless safinamide contains the Relevant Impurity at an amount below the Impurity Threshold, it will be unsafe for use in a drug product; and/or
(b) provides a basis for 0.03% (by weight) as the appropriate threshold above which the relevant drug product will be unsafe.
(ii) He said that in his view, "the information in the Patent does not provide a basis for either proposition".
(iii) The basis for this view was derived from his interpretation of the data in tables 1-4 on pages 4 to 6A of the 328 Patent, which (in summary):
(A) Do not provide any human in vivo safety data;
(B) Two are in vitro tests, and report on relative inhibition of various substances, but do not provide sufficient information to identify the human in vivo threshold which would render the product unsafe;
(C) Compare high purity safinamide with (tables 1, 3 and 4) 100% relevant impurity, and (table 2) 0.3% relevant impurity (10x the impurity threshold); and
(D) Do not compare the high purity safinamide with the percentages of relevant impurity produced by prior art synthesis methods in other examples in the patent.
(iv) In relation to the CYP 450 enzyme system and HERG channels, he notes that the statement as to their toxicity in the patent (at page 4) is "an overstatement, because it ignores the role of the dose".
(f) The opinions in (e)(iii) and (iv) above are expanded upon in some detail in paragraph 67 of Professor Roberts' affidavit onwards, noting that the 328 Patent does not provide information on what level of inhibition of CYP 450 enzymes or HERG channels would be unsafe. Tables 3 and 4 were mice mortality tests, which he said were not pointed to potential toxicity, but instead to whether the relevant impurity had the pharmacological activity of safinamide (relevantly).
(g) Basis for Impurity Threshold: Professor Roberts was not able to identify a scientific basis for 0.03% being the relevant threshold, and says that the 328 Patent notes that prior art methods resulted in higher amounts.
... does not provide any information which indicates that that ARX-Safinamide product may contain the Relevant Impurity at a percentage below the Impurity Threshold. Further, it enables calculations as to the estimated plasma concentration of Relevant Impurity at steady state, at various assumed concentrations, which demonstrates that there is no reason to believe the amount of Relevant Impurity may be below the Impurity Threshold.
there is no reason to believe the percentage of Relevant Impurity in the ARX-Safinamide products may be below the Impurity Threshold, because even amounts of Relevant Impurity far above that threshold would still result in blood plasma concentrations so low as to be therapeutically meaningless.
(1) A prospective applicant may apply to the Court for an order under subrule (2) if the prospective applicant:
(a) reasonably believes that the prospective applicant may have the right to obtain relief in the Court from a prospective respondent whose description has been ascertained; and
(b) after making reasonable inquiries, does not have sufficient information to decide whether to start a proceeding in the Court to obtain that relief; and
(c) reasonably believes that:
(i) the prospective respondent has or is likely to have or has had or is likely to have had in the prospective respondent's control documents directly relevant to the question whether the prospective applicant has a right to obtain the relief; and
(ii) inspection of the documents by the prospective applicant would assist in making the decision.
(2) If the Court is satisfied about matters mentioned in subrule (1), the Court may order the prospective respondent to give discovery to the prospective applicant of the documents of the kind mentioned in subparagraph (1)(c)(i).
(a) Does the prospective applicant believe that it may have a right to relief? (Noting that the belief is not whether there is a cause of action; rather, it is a belief in the possibility of relief).
(b) Is that belief reasonable? Or, turning the question around given the way the proceedings unfolded, with expert evidence, has the prospective respondent succeeded in showing that there is no reasonable basis for that belief?
(c) Have they made sufficient inquiries to obtain sufficient information to decide whether to start a proceeding in the Court to obtain that relief?
(d) If so, do they reasonably believe that the prospective respondent has documents directly relevant to the question of whether the prospective applicant has a right to obtain the relief?
(e) Would inspection of the documents assist?
(f) What are the confidentiality provisions which should be imposed on any discovery?
Do the prospective applicants believe that they may have a right to relief?
(a) Ms De Dominicis understands that the Arrotex products contain safinamide (the product argument);
(b) She understands that the Arrotex products are registered on the basis of bioequivalence to Xadago (the bioequivalence argument); and
(c) She understands that the Product Information documents for the Arrotex products include the Enzyme Statement, and believes that the TGA would not register an unsafe product (the safety argument).
(a) A reporting threshold at 0.05%, defined as the limit above which an impurity should be reported;
(b) An identification threshold at 0.1%, defined as the limit above which an impurity should be identified; and
(c) A qualification threshold at 0.15%, defined as the limit above which an impurity should be qualified and particular further measures must be taken.
There are no British Pharmacopoeia (BP) or USA Pharmacopeia (USP) monographs for the drug substance safinamide mesilate or the finished product
as appears in Exhibit 1 (Australian Government Department of Health, Australian Public Assessment Report for Safinamide (Therapeutic Goods Administration, Canberra, 2019)). Mr Murray asked, possibly rhetorically in the absence of evidence as to the kind of matters which give rise to pharmacopeia monographs:
... if some of the things said in the patent about the impurity levels for this drug are true, one would expect there to be a monograph telling the world ... and importantly regulators, "you should be applying this threshold".
The relevant question posed by the rule is whether the applicant reasonably believes that it may have the right to obtain relief. It is not whether one scientific view is more or less persuasive than another. In the field of science, expert views may differ about important scientific aspects that can be seen to bear upon a question.
There are a large number of substances that inhibit CYP 450 enzymes (e.g., grapefruit juice inhibits CYP3A4) and are not considered highly toxic. The issue is whether the amount of inhibition is of concern, taking into account the potency of the inhibitor, the likely concentrations of the inhibitor in the body, and the specific substance being inhibited.
As a result [of Professor Roberts' calculations], taking into account the likely blood plasma concentrations of Relevant Impurity in vivo, there is no reason to believe the percentage of Relevant Impurity in the ARX-Safinamide products may be below the Impurity Threshold, because even amounts of Relevant Impurity far above that threshold would still result in blood plasma concentrations so low as to be therapeutically meaningless.
I certify that the preceding one hundred and three (103) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Justice Needham.
Newron Pharmaceuticals S.p.A
Arrotex Pharmaceuticals Pty Ltd
(2017) 257 FCR 62
(2023) 174 IPR 377
(2005) 224 ALR 168
(1977) 180 CLR 236