IL 142809 to Pharmacia Successfully Opposed by Teva Pharmaceuticals

R&R          R&R2

IL 142809 to Pharmacia AB was submitted on 25 April 2001 as a national phase entry of PCT/SE/99/02052 “NEW CONTROLLED RELEASE BEAD, A METHOD OF PRODUCING THE SAME AND MULTIPLE UNIT FORMULATION COMPRISING IT”. This published as WO 0027364 on 11 November 1999. The application claims priority from another PCT application filed a year earlier.
On allowance in 2006, the patent published for opposition purposes and on 18 May 2006 Teva filed an Opposition, submitting a detailed statement of case on 18 October 2006. On 12 march 2007 Pharmacia filed a counter-statement. Both sides submitted evidence, held a hearing before then Deputy Commissioner Noah Shalev Shmulovich and then filed their summaries.

As per regulation 202a, the current commissioner, Asa Kling ruled on the opposition based on the material of record.

The application is directed to a bead with controlled release of active ingredients, a method of manufacture and a multi-part formulation that includes the active ingredients. Essentially, the bead comprises a multilayer structure that includes a soluble core covered with non-soluble coatings, and the patent has 23 claims, two of which are independent.

Claim 1 is as follows:

 A controlled release bead comprising:
A core unit of a substantially water-soluble or water-swellable inert material;
A first layer on the core unit of a substantially water-insoluble polymer;
A second layer covering the first layer and containing an active ingredient; and
A third layer of polymer on the second layer effective for controlled release of the active ingredient,
Wherein said first layer is adapted to control water penetration into the core.

Claims 2-7 recite the various lawyers and their formulations and thicknesses. Claim 8 is a Markush claim for various active ingredients. Claims 9and 10 claim different forms of the active ingredient. Claim 10 claims use in vitro. Claims 11-14 claim different materials for the first three coatings. Claim 15 provides dimensions for the core and claims 16 and 17 claim multidose structures.

Claim 18 recites a corresponding method as follows:

 A method of producing a controlled release bead, which method comprises the steps of:
providing a core unit of a substantially water-soluble or water swellable material;
applying a first layer of a substantially water-insoluble polymer to said core;
applying onto said first layer, a second layer comprising an active ingredient and optionally a polymer binder; and
applying onto said second layer, a third polymer layer effective for controlled release of the active ingredient;
Wherein the amount of material in said first is selected to provide a layer thickness that permits control of water penetration into the core.

Claims 19, 21 and 23 claim use of the bead for a treatment for various diseases and claims `19 and 21 claim the active ingredient as tolderene or a salt thereof.

Grounds for Opposition
The opposition was based on lack of inventive step (obviousness) under section 5 of the Israel Patent Law 1967. In addition, Teva claimed that some of the claims lack utility contrary to Section 3, that some of the claims lack support from the specification in contravention to Section 13 and the Application is laconic and contravenes Section 12.
Pharmacia argued that claiming that the specification was laconic was an inadmissible widening of the Statement of Case, but the Commissioner, Asa Kling felt that the alleged inadequacy of the specification was inherent in the Statement of Case and that Pharmacia related to the issue so he considered it admissible.
As to inventive step, the Commissioner explained that if at the time of filing, the claimed invention was a simple extrapolation that could be considered as a simple development within the field and allowing a patent for it would prevent progress, it would be incorrect to allow a patent.
The Commissioner noted that both sides accepted that beads allowing controlled release of active ingredients that comprised a miscible or non-miscible core, a sealcoat, layers of active ingredients and additional layers were known at the filing date. The sealcoat serves to protect the active ingredient from reaction with the core and may be water impervious or slightly pervious. In the present invention such water penetration was controlled but in the prior art it was less controlled.

Not that kind of seal coat

Not that kind of seal coat

The present invention differs from the prior art in two ways: (i) the sealcoat is miscible in the prior art but is immiscible in the present invention, and (ii) the seal coat of the present invention is rather thicker than usual, but the thickness is not mentioned in the claim-set.

Teva argued that since the core in this case is impervious the sealcoat is superfluous and non-functional and there is no effective difference from the core of the present invention and that of the prior art.

Teva argued that in the priority document this was stated explicitly:

“Each bead comprises (i) a core unit of a water-soluble, water-swellable or water-insoluble inert material (having a size of about 0.05 to 2 about 2 mm), such as e.g. a sucrose sphere; (ii) a first layer on the core of a substantially water-insoluble (often hydrophilic) polymer (this layer may be omitted in the case of an insoluble core, such as e.g. of silicon dioxide), (iii) a second layer of a water-soluble polymer having an active ingredient dissolved or dispersed therein, and (iv) a third polymer layer effective for controlled release of the active ingredient (e.g. a water-insoluble polymer in combination with a water-soluble polymer)”. (WO0012069 page 6 line 33 to page 7 line 6). This point was also clear from US 6,770,295 to the same applicants.

The Applicant countered that the opposer’s explanation of the phrase “control water penetration into the core” was a misrepresentation and the correct explanation is found on page 2 lines 23-25 of the Application and only rates to beads wherein the water penetration to the core is impeded in a controlled manner and excludes beads where the core is protected by an impervious layer. The Applicant argued that the claim of lack of inventive step was based on this wrong interpretation.  In contradistinction to immiscible cores of the prior art in the present invention the core is miscible and is protected by a partial barrier sealcoat which allows controlled release.
The applicant could not explain the working of the sealcoat and how it inhibited release of the active ingredient but argued that the phenomenon exists and this is sufficient for both enablement and inventive step.
It seems therefore, that the key question is whether an immiscible core or a miscible core protected by an immiscible coating are equivalent or if a miscible core protected by an immiscible coating can be considered inventive over an immiscible core. Citing 345/87 Hughes Aircraft vs. State of Israel, it is accepted that a mere scintilla of invention is sufficient, and the question is whether this exists in the present case.

Utility
Teva argued that the utility was not demonstrated in contravention of Section 3 which allows patents for inventions that are new, useful, industrially applicable and non-obvious.
In oppositions, the onus is on the applicant to show utility. Citing 665/84 Sanofi vs, Unipharm the commissioner stated that the application as field has to provide a basis for utility and, if challenged, the Applicant has to prove utility during opposition proceedings. IN enforcement and cancellation proceedings the burden of proof switches and the challenger has to show a lack of utility. Consequently, the Commissioner ruled that without proof of usefulness a patent should not be granted.

According to the Specification, there are three advantages:

  • The claimed bead prevents the soluble core from serving as a reservoir of the active ingredient and extending the controlled release period
  • It reduces the likelihood of the core material releasing active ingredients and reduces the atmospheric pressure (specific vapour pressure?) and prevents the core from swelling
  • It reduces the initial phase during which there is no release of the active ingredient or only minimal release

According to the applicant these advantages transcend specific active ingredients.

The Opposer argued that these advantages are claimed for the specific active ingredient and for other non-specified active ingredients without any rationale or evidence.

Evidence
The evidence from each side consisted of expert opinions. Teva produced an expert opinion from Professor Golomb, and Pharmacia releid on expert opinions from Professor Wilson and from a Professor Walther who attempted to reproduce the experiments described in the application.
Professor Walther conducted a number of experiments to demonstrate that claimed in the first example for different active biological compounds. These, together with raw data were appended to Professor Walther’s affidavit at the Commissioner’s request.
There were differences between the raw data and the final conclusions with regard to what active species showed the desired effects and whether a heat treatment affected the results. The Commissioner felt that the discrepancies required explanation.
The Applicant claimed that Tolterodine exhibited the desired behavior, as did Reboxetine and cona, theopheylline and Carbamazepine. This was held sufficient to show that the behavior was a general phenomenon.
The tests related to a core with three coatings whereas the specification proposed a fourth optional coating. This, together with other discrepancies were considered to show light on the utility.
The thick initial layer did show slow release of the Tolterodine in a manner that was close to linear.
In the Application, after three hours some 70% of the active ingredient ws released, but in Dr Walther’s corroborative experiments, after this time lapse, only 43% of the active ingredient had been released.
When comparing Professor Walther’s results with the experiments in the specification it appears that the applicant had problems repeating their own experiments. The problem seems to be that Professor Walther simplified the experimental design and still could not achieve meaningful results. He was able to show that a thicker coating impeded release of the active ingredient but not in a qualifiable and repeatable manner.
As far as Tolterodine, the preferred active ingredient was concerned, Professor Walther was unable to show a correlation between thickness and the rate of release and was unable to repeat the examples in the Application. The Commissioner considered the lack of repeatability an reproducibility as undermining the claimed utility and barring the issuance of a patent.
Adequacy of the Specification
Section 12 requires that the specification be adequate to allow persons of the art to implement the invention. The rationale for granting a patent is in exchange for teaching something useful and failure to teach something sufficiently to allow the teaching to be repeated is considered as invalidating the application: “The sufficiency of a specification is a question of fact and necessarily depends upon the nature of the invention and attributes of the skilled person.” ( Hollister [1993] R.P.C. 7 para. 10-14). In this instance, the purpose of the patent as specified in the priority document was to enable the controlled release of the active ingredient at a predetermined rate over the shelf life of the product.
“An important aspect of all controlled release dosage forms relates to the need for consistent drug release between dose units prepared in the same and/or in different production batches, and throughout the shelf-life of the finished product.”

The surelease polymer specified in the specification and used by Professor Walther in his experiments was supposed to provide repeatable and reproducible results:

“In one embodiment, the invention provides a commercial-scale process for manufacture of controlled-release dosage units. The process comprises co-formulating tolterodine or a tolterodine-related compound as an active drug and a pharmaceutically acceptable polymer-based release-controlling component. … more preferably substantially all of the polymer-based release-controlling component used in the process has an age, at time of dosage unit manufacture, which varies by not more than about 180 days, preferably not more than about 120 days, and more preferably not more than about 90 days.”

Professor Walther was unable to show this control. Under cross-examination he stated that:

“So what we know is that Surelease has lot to lot variability. So one batch of Surelease may perform slightly different from another batch of Surelease. That is an effect that the suppliers do know and understand and that is something that, as part of any formulation development, you would establish how robust a product is towards variability and providing sufficient specifications then on it.”

The problem is that this variable is not described in the specification, rendering the claimed invention not enabled.
The Commissioner ruled that the claimed invention does not have demonstrable superiority, lacked sufficient disclosure and enablement and that no inventive step was shown. Consequently the application was refused.

COMMENT
Active ingredients are released from the surface of solids. This is true for components that leach out and for components that are released when a carrier dissolves.
As particles shrink, the surface area to volume ratio increases and the rate of dissolution increases. Having a non-functioning core surrounded with a coating containing active ingredients is to ensure that the effective surface area remains more or less constant and thus the active ingredients are released at a constant rate.
The above explanation is obvious to anyone with a background of materials science and chemistry.
Drugs are more effective if the dosage is released slowly at a constant and predictable rate.
The present invention seems to be based on the premise that over time the core will absorb the active ingredient and that a coated absorbent core is better than a non-absorbent one.
The application is based on Tolterodine as an active material, but other pharmaceutical compounds may be expected to behave in the same way.
Of course, using the same binder and beads of constant diameter won’t give reproducible results if there are other significant variables. The problem here is that the Applicant’s own attempts to demonstrate the efficacy of the claimed invention failed. In such circumstances, the Commissioner couldn’t really have come to a different conclusion than that the application was deeply flawed as the person of the art selected by the applicant was unable to reproduce the results.

The previous Deputy Commissioner resigned four years ago. Obviously this was only one case of many that the current commissioner and his deputy or adjudicator had to rule on. Nevertheless, it seems to me intolerable that the parties should have to wait for four years for this ruling and one wonders why the previous deputy commissioner couldn’t have left less abruptly, and finished these pending cases.

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: