Board of Patent Appeals and Interferences
Patent and Trademark Office (P.T.O.)
*1 HOFFMAN ET AL.
SCHOENWALD ET AL.
Patent Interference No. 101,699
February 22, 1990
Final Hearing: July 25, 1989
Ethers of Hydroxybenzothiazole-2-Sulfonamide for the Topical Treatment of
Elevated Intraocular Pressure
Patent granted to Jacob M. Hoffman, Jr. and Otto W. Woltersdorf, Jr., Patent No. 4,505,923 issued March 19, 1985, filed October 31, 1983, Serial No. 547,189.
William H. Nicholson, Mario A. Monaco, Rudolph J. Anderson, Jr. and Raymond M. Speer for Hoffman et al. Oral argument by Raymond M. Speer
Donald H. Zarley, Bruce W. McKee, Dennis L. Thomte, Michael G. Voorhees, Edmund J. Sease, John A. Beehner, Mark D. Hansing and Kirk M. Hartung for Schoenwald et al. Oral argument by Edmund J. Sease
Before R. Smith, Sofocleous and Kimlin [FN1]
This interference involves a patent of Hoffman et al (Hoffman), Patent No. 4,505,923, issued March 19, 1985 and assigned to Merck & Co., Inc., and an application of Schoenwald et al (Schoenwald), Serial No. 720,007, filed April 4, 1985 and assigned to University of Iowa Research Foundation.
The subject matter of the interference relates to benzothiazole-2-sulfonamide compounds which are useful for the topical treatment of elevated intraocular pressure. Count 1, the sole count at issue, reads as follows:
A compound of structural formula:
or ophthalmologically acceptable salt thereof wherein:
(2) C1-5alkyl or
(3) R1 and R2 joined together directly or through a heteroatom selected from O, N or S to form a 5 or 6-membered heterocycle with the nitrogen to which they are attached, wherein the heterocycle is selected from pyrrolidino, piperidino, morpholino and thiazolidino,
(g) carboxy, or
(h) C1-3alkoxycarbonyl; or
The claims of the parties which correspond to this count are:
Hoffman : Claims 1-9.
Schoenwald : Claims 1-14.
Schoenwald is senior party by virtue of the February 4, 1983 filing date of his parent application Serial No. 464,063. Schoenwald was accorded the benefit of the February 4, 1983 filing date by the primary examiner upon declaration of the interference. Hoffman filed no motion pursuant to 37 CFR 1.633(g) to attack Schoenwald's entitlement to the benefit of his February 4, 1983 filing date during the motion period, and Hoffman is therefore not entitled to raise that issue in his brief at final hearing (37 CFR 1.655(b)).
*2 As noted by Hoffman in his brief and in accordance with the settlement agreement of March 15, 1988 between the parties, as interpreted by the Examiner-in-Chief in Paper No. 34, the issues at final hearing are limited to the priority issues of conception, diligence and reduction to practice.
Hoffman's Case for Priority
Hoffman, as the junior party to this interference, has the burden of proving prior invention by a preponderance of the evidence. Cf. Peeler v. Miller, 535 F.2d 647, 190 USPQ 117 (CCPA 1976). In an effort to prove prior invention Hoffman submitted an evidentiary record including the declaration testimony of inventors Hoffman and Woltersdorf and corroborating witnesses Schwam, Sugrue, Smith, Lumma and Sondey and associated exhibits. References to the Hoffman record will be designated as HR, followed by the record page number, and references to Hoffman exhibits will be designated HX, followed by the declarant's name and exhibit number.
Hoffman and Woltersdorf testified that they conceived of a new class of benzothiazole-2-sulfonamides as carbonic anhydrase enzyme inhibitors on or about February 8, 1982. Their conception included a suitable method of preparing the 6-ether compounds by treatment of the 6-hydroxy compound with an alkenyl halide (HR 14, 15,33-35; HX Woltersdorf 3). Hoffman began preparing the 6- (2,3-epoxypropoxy)benzothiazole-2-sulfonamide compound on July 19, 1982 and by August 5, 1982 he established that the desired compound had been prepared based on proton nmr (HR 15-17; HX Hoffman 3, 4, 5, 6).
The compound prepared by Hoffman was designated L-648,875-00B01 and was submitted for evaluation of its activity in inhibiting the carbonic anhydrase enzyme (HR 18; HX 10). On September 9, 1982 Sondey completed the evaluation, and he testified that the results showed that compound L-648,875-00B01 "was an active inhibitor of the carbonic anhydrase enzyme"' (HR 39-41, HX Sondey 4). Hoffman urges that the successful demonstration of the ability of the 6-(2,3- epoxypropoxy)-benzothiazole-2-sulfonamide species within the genus of count 1 to inhibit the carbonic anhydrase enzyme establishes that an actual reduction to practice of the invention of the count took place on September 9, 1982.
Opinion re Hoffman's Case for Priority
We hold that Hoffman has established conception of the invention of count 1 by February 8, 1982, the date of Woltersdorf's memo to Smith, which discloses the allyl ether compound within the count, as corroborated by Smith. We hold further that Hoffman has proven by a preponderance of the evidence actual reduction to practice of the invention of count 1 by September 9, 1982, prior to Schoenwald's February 4, 1983 effective filing date.
Schoenwald's only argument with respect to Hoffman's case for priority is that Hoffman's conception was not sufficiently complete as of February 8, 1982. We disagree. The 6-allyloxy compound disclosed in HX Woltersdorf 3 is a compound within the scope of the count, and its preparation would have been obvious to one of ordinary skill in the art on February 8, 1982. Cf. Miller v. Walker, 214 USPQ 845 (Bd. Pat. Int. 1982) and Oka v. Youssefyeh, 849 F.2d 584, 7 USPQ2d 1169 (Fed. Cir. 1988). Conception of a species within the genus constitutes conception of the genus for priority of invention purposes.
Schoenwald's Case for Priority
*3 Schoenwald, the senior party, has presented an evidentiary record including the declaration testimony of co-inventors Barfknecht and Schoenwald, both professors of pharmacy at the University of Iowa, the declaration testimony of their graduate students, Dixson and Eller, and associated exhibits. References to the Schoenwald record will be designated as SR, and references to the Schoenwald exhibits will be designated SX, followed by the exhibit number. Schoenwald relies on the evidence in an effort to establish conception of the invention of the count prior to the February 8, 1982 conception accorded to Hoffman, supra, and reasonable diligence from prior to Hoffman's February 8, 1982 entry into the field until Schoenwald's constructive reduction to practice on February 3, 1983.
Dixson testified that he was a graduate student working under the direction of Professor Barfknecht, and that his assignment involved the preparation of compounds to be investigated as possible carbonic anhydrase inhibitors (SR 43- 44). One of the compounds known as D-3 was 6-amino-2-benzothiazolesulfonamide and another known as D-5 was 6- hydroxyethoxy-2-benzothiazolesulfonamide. Dixson testified further that his efforts to synthesize compounds D-3 and D-5 began in the summer of 1981 (SR 45-46). From the summer of 1981 through February 4, 1983 Dixson worked on the synthesis of many different 2- benzothiazolesulfonamides, "at least 17 benzothiazole final products"' were prepared, and with intermediates required the synthesis of more than 60 compounds (SR 45-46). Dixson synthesized compound D-3 and verified its structure by October 7, 1982 (SR 48; SX 20, 21). On November 15, 1982 he submitted the compound D-3 to Schoenwald for further work by his graduate student, Eller (SR 46; SX 22).
Dixson's efforts at trying to synthesize compound D-5 are set forth in his progress report for the fall of 1982 (SR 46, SX 13). The efforts were not successful. On February 23, 1983 Dixson successfully prepared compound D-5, after the constructive reduction to practice on February 4, 1983.
Eller testified that he was a graduate student working for Dr. Schoenwald on projects in the area of carbonic anhydrase inhibitors (SR 50, 51). Eller worked "on various carbonic anhydrase inhibitors that included the parent or prototype structure of 2-benzothiazolesulfonamide" and investigated the "pharmaceutical activities of these compounds virtually continuously from June 1980 until I received my Ph.D. degree in 1984"' (SR 51). Eller's work included developing the physical and chemical properties of compounds prepared by Barfknecht and Dixson, determination of solubility, pKa and partitioning, responsibility for testing carbonic anhydrase inhibition by the Maren Micro Method, responsibility for corneal permeability testing, and intraocular pressure determinations in vivo, in rabbit eyes.
Opinion re Schoenwald's Case for Priority
We hold that Schoenwald has established by a preponderance of the evidence conception of the invention of count 1 by June 11, 1981, prior to the February 8, 1982 conception accorded Hoffman, supra, and that Schoenwald has established reasonable diligence from prior to February 8, 1982 until his constructive reduction to practice on February 4, 1983.
*4 With respect to conception, Schoenwald points out in his brief (page 21) that Hoffman "has not disputed the conception date of Schoenwald of June 11, 1981."' Nor has Hoffman contested, in his reply brief, or at final hearing, Schoenwald's prior conception. Rather, Hoffman conceded at final hearing that Schoenwald has an earlier conception, i.e., by June 11, 1981.
In order to prevail on the basis of prior conception coupled with reasonable diligence, Schoenwald must establish that he was reasonably diligent from a time just prior to Hoffman's conception on February 8, 1982 until Schoenwald's constructive reduction to practice on February 4, 1983, a period of about 12 months. After a careful consideration of all of the evidence presented by Schoenwald and the positions of the parties as set forth in their briefs, we have concluded that Schoenwald has established the requisite reasonable diligence.
Hoffman urges that in judging the reasonableness of Schoenwald's activities during the critical period it should be noted that Hoffman was able to reduce the invention to practice in 52 days from the time that the preparation of the compound was begun. In contrast, Dixson was unable to synthesize compound D-5 during the 12 month period for which diligence is required. It took Dixson, who was working only one-half time, as long as a month to make one compound. Hoffman urges that it was a conscious decision on the part of Schoenwald's assignee to require Schoenwald to seek outside support and to rely on a graduate student of limited experience which resulted in the delay, citing Griffith v. Kanamaru, 231 USPQ 892 (BPAI 1986).
We believe that Hoffman's reliance on Griffith is misplaced. Griffith sought to excuse a gap in activity where there was no work toward a reduction to practice of the invention based on the need to secure outside funding for the project before the work could proceed. In contrast to the situation in Griffith, Schoenwald and Barfknecht had funding for their project throughout the diligence period, and it is clear from the testimony of Dixson and Eller that they were diligently working on the project to the extent that their positions as graduate students allowed throughout the critical period. It is a principle of diligence that consideration must be given to the circumstances of the inventor, including his skill and available time, and that the inventor may avail himself of the activities of others. I Rivise and Caesar, Interference Law and Practice, §§ 101,108 (Michie Co. 1940). Accordingly, we find that the diligent activities on behalf of Schoenwald are not negated by the fact that Dixson and Eller did not possess the same level of skill as Hoffman or that Dixson and Eller were not able to work full time on their project. Similarly, it is not material to the question of diligence that Schoenwald did not take the most expeditious course, so long as there was diligent activity toward the end in view. I Rivise and Caesar, Interference Law and Practice, supra, § 196.
*5 The central issue as to Schoenwald's case for diligence is whether Schoenwald is entitled to consideration of work by Dixson in preparing compounds outside the scope of the count. In this connection Hoffman relies on the decision in Smith v. Crivello, 215 USPQ 446 (Bd. Pat. Int. 1982), for the proposition that a party charged with diligence may not rely on activities directed toward another independent invention. We find, however, that the facts of this case are more similar to those in Ginos v. Nedelec, 220 USPQ 831 (Bd. Pat. Int. 1983) than they are to Smith, supra. Whereas Smith was not permitted to rely on activities directed toward another independent invention, Ginos was continuously working on the preparation of other compounds which were considered by Ginos to be part of the same invention and which were included in his application. We believe that Schoenwald is similarly entitled to be credited with the work of Dixson in preparing compounds within the scope of Schoenwald's invention of 2-benzothiazolesulfonamide compounds which were included in Schoenwald's parent application and were manifestly considered by Schoenwald as part of the same invention.
Hoffman urges that the public policy favoring early disclosure of inventions should preclude according Schoenwald with a "reservoir of reasonable diligence"' on the basis of the ongoing carbonic anhydrase inhibitor research project which included much work on compounds outside the scope of the present count. Hoffman's reliance on the public policy favoring early disclosure ignores the fact that Schoenwald was the first to file his patent application and was therefore the first to initiate the process leading to public disclosure. Thus, the public policy favoring early disclosure supports our decision according priority of invention to Schoenwald.
For the foregoing reasons, judgment as to the subject matter of count 1 is awarded to Ronald D. Schoenwald and Charles F. Barfknecht, the senior party. Accordingly, Hoffman is not entitled to a patent containing claims 1-9, corresponding to the count, and Schoenwald is entitled to a patent containing claims 1-14, corresponding to the count.
BOARD OF PATENT APPEALS AN INTERFERENCES
Ronald H. Smith
Edward C. Kimlin