Honorable Sidney H. Stein 

U.S. District Judge 

Southern District of New York 

500 Pearl Street, Room 1010 

New York, NY 10007 

RE: SANORI SYNTHELABO ET AL v. 

APOTEX, mC. ET AL 

SUB: CIVIL ACTION NO. 02-CV-2255 

OUR REFERENCE NO.; A1047140021 

Dear Judge Stein: 

Apotex submits this Letter Motion requesting the Court to stay the preliminary injunction 

pending an appeal to the Court of Appeais for the Federal Clrcu~t because Apotex has ruse 

substantialqucshonse validity or tiiFTS5 patent. Apotex submits this letter vi 

facsimile m thc Court so graciously allowed. 

Although Apotex believes that each and every one of its defenses raise substantial 

questions of invalidity, Apotex specifically directs the Court's attention to irs anticipation 

defense under 35 U.S.C. $ 102(b). 

As this Court explained, "[a] prior art reference renders a patented invention anticipated - and thus invalid - if it discloses every feature of the claimed invention, either explicitly or 

inherently." Order at p. 14 (internal quotations omitted). Furthermore, a prior art reference 

discloses the features of the claimed invention where it "describel:s] every element of the 

invention, either expressly or inherently, such that a person of ordinary skill in the art coul 

practice the invention without undue experimentation." Id. That is, the reference must be 

enabling. See Id. 

The prior art reference at issue is Sanofi's own patent: U.S. Potent No. 4,529,596 ("the 

'596 patent"). The Court agreed that the '596 patent is prior art to the patent in suit, and 

moreover noted that "the parties have stipulated that clopidogrel bisulfate is a compound that is 

within the genus of claim one sf the '596 patent" Id at 14-15 (internal quotations omitted). 

The Court however held that the '596 patent does not (1) describe clopidogrel bisulfnte (2) so as 

to enable one skilled in the art to create it absent undue experimentation. Order at pp. 20-28. 

11" Floor - Seven Penn Center. 1635 Market Street - l'hiladelphi4 PA 191 03-221 2 

Telephone: 21 5-567-2010 - Fax: 215-75 1-1 142 - ww\u.crbcp.com 

Case 1:02-cv-02255-SHS Document 309 Filed 09/01/2006 Page 1 of 4
Honorable Sidney H. Stein 

September 1,2006 

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Thus, the Court found that although Apotex successfully raised a substantial question of 

invalidity insofar as anticipation is concerned, Sanofi demonstrated that such question "lacks 

substantial merit." Order at 19. 

Central to the Court's holdmg that Sanofi demonstrated that Apotex' substantial question 

of invalidity vis-b-vis anticipation lacked substantial merit, was the Court's belief that deriving 

clopidogre1 bisulfate from the '596 patent's dirclosure would be like finding a needle in a 

haystack. Particularly, the Cornt found that the '596 claimed a genus which included potentially 

hundreds of thousands, if not dons of various species, including clopidogrel bisulfate. Thus, 

although clopidogrel bisulfnte is one possible embodiment of the invention claimed in the '596 

patent, the Court found that the patent includes too many possibilities for a person skilled in (he 

art to arrive at clopidog~el absent undue experimentation. Apotex respectfully disagrees. 

According to the Courf the potential hundreds 01' thousands, if not millions of potential 

embodiments of the genus claimed in the '596 patent renders the '596 patent a nonanlicipato~y 

reference as to one of those single embodiments. This is simply not true. The potential llkely 

embodiments which a person of ordinary skill in the art (POSA) would pursue based on the 

disclosure in the '596 patent, are, in fact, very few. First, PCR 4099, which is covered by the 

'596 patent, was hown to have anti platelet aggregating characteristics. Based on evidence 

presented to the Court, it was well known in tbe art (for decades prior to the patent-in-suit) that 

separate enantiomers of a racemate could have different properties. In the context of undue 

experimer~tation, it is irrelevant whether the enantiomers would definitely have different 

properties and whether a POSA could predict what exactly the differences would be. A racemate 

has only two enantiomers - the levorotatory enantiomer and the dextrorotatory enantiomer. A 

POSA has two choices in enantiomers of the claimed PCR 4099. This is certainly not an 

overwhelming number of choices. Apotex presented evidence establishing that a POSA was 

well versed, decades prior to the patent-in-suit, m methods of separating a racemate into its 

individual enantiomers. Moreover, as a United States patenf the '596 patent is presumed to be 

enabling (otherwise it would be invalid). Thus, there is a legal presumption that a POSA would 

have understood fiom the '596 patent how to separate PCK 4099 into its constituent enantiomers. 

Since the '596 patent covers the racemate PCR 4099, its enantiomers and its mixtures, it most 

certainly "describes" clopidogrel, i.e. the dextrorotatory enantiomer of PCR 4099. 

Furthermore, although the court noted that Sanofi's expert, Dr. Dnvies said that ere are 

50 pharmaceutically acceptable salts (Order at p. 16, n. I), this estimate means that a POSA 

would at most potentially experiment with two enaneiomers of PCR 4099 and 50 salts, rende~g 

a total of 100 possible combinations, as opposed to millions. That alone would not require undue 

experimentation. Moreover, only three salts are specifically disclosed in the examples given in 

the specification of the '596 patent, including the bisulfate. Thus, a POSA faced with seeking 

out an improved anticlotting drug based on PCR 4099 as disclosed in the '596 patent would, in 

all likelihood, experiment with two enantiomers and rhree different salts, i.e. a total of six 

different realistic choices. This would not, by any stretch, be considered "due 

experimentation." 

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Honorable Sidney H. Stein 

September 1,2006 

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Respectfully, the court's decision does not cite controlling case law. The court's decision 

does not c,ite or discuss: 

In re A&mson, 275 F.2d 952, 954 (C.C.PA. 1960) ("In view of the teaching of Karrer 

we feel that one of oralnary skill in the stereoisomer and pharmaceutical arts would recognize 

that the Adamon compounds exist as racemates. hence the fact that no reference to 

stereoisomerism is made in the Adamson references themselves is of no moment"). 

See In re Petering, 301 F.2d 676, 682 (C.CP.A. 1962) (holding that when a reference 

reference:; a discrete class of readily identified members, that reference "has described to those 

with ordinary skill in this art each of the various pernutations . . . as fully as if he had drawn each 

strucnual formula or had written each name"); see also In re Schaumann, 575 F.2d 312, 

(C.C.P.A. 1978) (reaffirming Pelering, and finding that "the reference provides a description of 

those compounds just as surely as ifthey were identified in the reference by name"). 

"[I) is well lcnown to those skilled in the art that racemic mixtures are potentially separable, for 

Karrer teaches that racemafes may be resolved into their laevo- and dextro-isomers by one of 

several methods including the specific method utilized, though not claimed, by appellants." 

Adamson, 275 F 2d 954 

Apotex urges this Court to reconsider its analysis regarding the '596 patent's enablement 

of clopidogrel bisulfate, and consider the probabilities of a POSA formulating clopidogrel 

bisulfate based on the '596 patent's disclosure of PCR 4099. It is incorrect to assume that every 

possibility would be tried without any rhyme or reason. Apotex presented su£ficient evidcnce to 

show that a POSA would be logically limited to a finite number of possibilities, based on the 

examples specifically show in the '596 patent. 

An analogy may be helpful. Suppose a person wished tn fmd a phone number of a 

bookstore in the vicinity of a certain geographic location. This person has a county phone book. 

The phone book contains hundreds of thousands of entries. Thus, the person could potentially 

read each of the hundreds of thousands of entries before finding the enay for the store. This 

absurd redt is based on an assumption that the person does not real& that the phone book is 

orgmized alphabetically as well as by subject matter. Obviously, if the person recognizes the 

logic underlying the organization of the phone book, the potential difficulty in locating the 

desired phonebook enby is reduced exponentially. Sdarly, it is faulty to assume that a POSA 

would unduly experiment with potentially hundreds of thousands or even millions of 

permutations of the genus claimed in thc '596 patent. 'The actual combinations which a POSA 

would be likely to try (including clopidogrel bisulfate) based on the specification, does not 

amount to undue experimentation. 

The Court of Appeals for the Federal Circuit recently explained: "In resisting a 

preliminary injunction . . . one need not make out a case of actual invalidity. Vulnerability is the 

issue at the prclirmnary injunction stage, while validity is the issue at trial. The showing of a 

substantial question as to invalidity thus requires less proof than the clear and convincing 

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OO/Ol/o6 15:OO FAX 

Honorable Sidney H. Stein 

September I, 2006 

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showing necessary to establish invalidity itself." Abbo~r Labs., 452 F.3d at 1335 (quoting 

Amuzon.com, Inc.. 239 F.3d at 1359) (emphasis added). 

In light of the above analysis, as well as all of the evidence of record, Apotex has clearly 

demonstrated the "vulnerability" of the patent-in-suit to a potential fmding of invalidity. Apotex 

therefore i:espectMly requests that this Court reconsider its ruling regarding anticipation and find 

that Apotex has raised a substantial question of validity wammting a stay of the prelirmnary 

injunction. 

Furthermore, in view of the foregoing, the Court is urged to reconsider its finding 

regarding irreparable harm Absent the finding on Likelihood of success, Sanofi would not have 

successfully demonstrated lrreparable harm, as Apotex presented sufficient evidence that 

Sanofi's potential ham was cnlculable in monetary terms. Based upon the clear irreparable 

ham to Apotex by reason of the loss of the six month exclusivity and the hanu ro the public, it is 

respectFully submitted that a stay is appropriate. 

Rt:spectfully, the Court's decision on the prospect of Sanofi's suffering irreparable baxm 

from irreversible price erosion caused by ongoing sales is unsupported by the evidence and 

testimony. The court did not cite evidence of record on the issue of on-going harm proffered by 

defendant's expert. 

Conclusion 

Fc~r all the foregoing reasons and those set forh in Apotex' Opposition to Plaintiffs' 

Mot~on for a Prel~minary Injunction, Apotex respectfully requests that the Court stay the 

injunctior~ 

Apotex' counsel is available to discuss this matter at the court's earliest convenience and 

mny be reached at 215-498-1894 ifthe Court is unable to reach counsel at their offices. 

Respectfully submitted, 

CAESAR, RMSE, BERKSTEIN, 

COHEN & POKOTILOW, LTD. 

cc: Evan Chesler, Esq. (via facsimile and Federal Express - Saturday Delive~y) 

Rt~bert Buchtold, Esq. (via facsimile and Federal Express - Saturday Delivery) 

Karen J. Bemstein, Esq. (via facsimile and Federal Express) 

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