[co-authors: Kieran Williams, Ph.D. | Cotters, Clare Salisbury | Gowling WLG, Wenwen Wang, Ph.D. | Advance China IP Law Office, Glyn Truscott | Elkington +Fife, Shinichi Watanabe, M.Sc. | K. Ito & Associates, Hye-Jin Han | Kim & Chang, Malathi Lakshmikumaran Ph.D. | Lakshmikumaran & Srdharan, and Rommy Morales, M. Sc. | Olivares]*
Intellectual Property counsel often face the dilemma of when to file a patent application: as soon as possible, or wait and gather more support? Filing an application “early” helps to avoid anticipatory prior art but if the application is filed too early, the applicant may risk rejections during examination for lack of supportive evidence.
On the other hand, if the application is filed too late, the applicant may lose the priority date. This is especially problematic for biopharma industry applicants where on one hand, these data are often critical for securing a patent; on the other hand, the research and development cycle is long and generating experimental and clinical trial data require significant resources and time to obtain, and business and financial reasons can also render it difficult to predict when the data will become available. Frequently supporting data and related information are not available until after the application is filed. Filing a series of provisional applications when data are available does not always remedy the problem. The applicant is left with a difficult decision - whether or not to convert the provisional application(s) into a PCT application (or other non-provisional applications). Further complicating this difficult decision is that not all jurisdictions treat post-filing data in the same manner; even in the same patent office, patent examiners do not treat all post-filing data the same way. This can cause confusion and uncertainty for companies seeking to obtain global patent portfolios.
Is it too late to submit data after filing the application? This article compares and analyzes how post-filing data are treated in jurisdictions that many biopharma companies are interested in obtaining patent protection for their products.
Post-filing data and expert declarations have long been used in Australia to overcome inventive step objections, and recent case law has established that post-filing data may also be used to overcome enablement/sufficiency objections.
Australian patent law requires a claimed invention to be described in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art. Therefore, the specification must provide sufficient information to enable the skilled person to perform the invention across the scope of the claims without undue burden or the need for further invention.1 Specifically, the applicant must establish that: (1) it is plausible that the invention can be worked across the full scope of the claims; and (2) the invention can be performed across the full scope of the claims without undue burden.2
In BASF Corp.  APO 34 (U.K.), the Delegate of the Patent Office cited United Kingdom case law to establish that post-filing data can be used to address sufficiency issues. The Delegate referenced a statement by the UK Court:
[t]his does not mean that subsequent data is never admissible in a dispute about sufficiency, but the purpose for which it is admitted is strictly limited. Where the asserted therapeutic effect is plausible in the light of the disclosure in the patent, subsequent data may sometimes be admissible either to confirm that or else to refute a challenger’s contention that it does not actually work . . . it cannot be a substitute for sufficient disclosure in the specification.3
In this case, BASF Corporation was able to overcome a rejection that the application did not provide an enabling disclosure of all species falling within the scope of the claims by submitting evidence and a declaration from the inventor. Said evidence supplemented the evidence contained in the specification and refuted the contentions of the examiner regarding the unpredictability of synergy. This evidence was found admissible as it related to the expectations of the skilled person understanding the specification as filed and the common general knowledge as of the filing date.
In Canada, obviousness is assessed in light of the state of the art as it was on the claim date . However, post-filing data showing evidence of commercial success of the invention may be used as one of several factors considered in establishing non-obviousness.5
Post-filing data cannot be used to establish utility in Canada. Utility of an invention must be established either by demonstration or sound prediction.6 The demonstration must have occurred as of the filing date, but information establishing the demonstrated utility need not have been included in the description and may be provided after the filing date.7 Soundly predicted utility pertains to embodiments of the invention that have not been demonstrated to have utility, but for which an appropriate factual basis exists upon which this utility can be predicted. That is, the scientific rationale underlying the utility must have been established through a sound prediction at the time of filing.8 Where a sound prediction relies on additional information that is not publicly available, such information must be included in the description at the time of filing. In contrast with evidence that demonstrates utility, an applicant cannot provide evidence after the filing date to establish utility by sound prediction, even if the evidence was generated before the filing date.9
In Eli Lilly & Co. v. Teva Canada Ltd.,  FCA 220 (Can.), a patent claim for use of a drug, atomoxetine, to treat ADHD was found to be invalid for lacking utility. The application described how to use atomoxetine to treat ADHD, the criteria for identifying the relevant patient population, the preferred routes of administration, and the preferred daily doses. However, because there was no in vitro or animal model of ADHD, data establishing that atomoxetine would be effective in treating ADHD could only be shown through clinical trials of the drug on human patients having the disease. The Federal Court of Appeal held that, because clinical trials had not been disclosed in the application as filed, the patent did not meet the requirement of disclosing the factual basis from which utility of the claimed invention could be soundly predicted. In another decision, Eli Lilly Canada Inc. v. Apotex Inc., 2009 FCA 97, the Federal Court of Appeal similarly held that failure to disclose data supporting a sound prediction of utility for the use of the drug raloxifene to treat osteoporosis rendered the patent invalid. The Court found that a human trial undertaken by Eli Lilly did adequately establish the utility of the drug, as a matter of sound prediction; however, because data from this trial had not been disclosed in the patent as filed, the patent was invalid.
Accordingly, whether the utility of an invention is established by demonstration or sound prediction, it must do so as of the date of filing the application, rendering post-filing data of limited usefulness in Canada.
In recent years, China has gradually relaxed its traditionally strict stance towards post-filing data, giving new hope to applicants who had not previously been able to have post-filing evidence considered. The Chinese National Intellectual Property Administration (CNIPA) Patent Examination Guide first became effective in 2010, and since then, have been amended six times. The third amendment to the Patent Examination Guide came into effect on April 1, 2017, and for the first time explicitly stating that an examiner should examine post-filing data, provided the technical effect from the post-filing data could have been determined by one skilled in the art based on the disclosure at the time of filing.10
The recent Economic and Trade Agreement between the Government of China and U.S. (published 16 January 2020) (“Agreement”) firmly confirms that “China shall permit pharmaceutical patent applicants to rely on supplemental data to satisfy relevant requirements for patentability, including sufficiency of disclosure and inventive step, during patent examination proceedings, patent review proceedings, and judicial proceedings.”11 Consistent with the Agreement, China amended the Patent Examination Guide a sixth time, and the sixth amendment, which came into effect on January 15, 2021, requires the examiner to consider relevant experimental data for both inventive step and sufficiency of disclosure under Article 22(3)12 and Article 26(3)13 of the Patent Law.”14
The amended patent examination guide provides two examples relating to pharmaceutical inventions. The first example describes a claim directed to a compound. The as-filed application describes the compound as having the effect of lowering blood pressure and methods of measuring the compound’s activity of lowering blood pressure, but the experimental data were not disclosed in the as-filed application. The revised patent examination guide states that the examiner should consider the applicant's post-filing data demonstrating the compound lowered blood pressure.
The second example describes a claim directed to compounds having formula I. The as-filed data show the IC50 of the compound’s antitumor effect is in the range of 10-100 nM. The as-filed specification of the second example also describes the methods for determining the antitumor effect. The applicant submitted comparison data to demonstrate the compound is inventive, and indicating the data demonstrates the compound has an IC50 of 15 nM in treating tumors, while the reference prior art compound has an IC50 of 87 nM. The amended Guide requires that in this scenario, the examiner should consider the post-filing data when determining the inventive step of the claim. Thus, to provide a clear basis for post-filing data it is a good practice in China to describe the technical effect as well as the methods for determination thereof in the as-filed application.
Finally, the Supreme People’s Court published a new provision explicitly requiring courts to examine post-filing data for compliance with Article 22(3) and Article 26(3) of the Patent Law in appeals against the re-examination decision and invalidation decision of CNIPA. The provision became effective as of September 12, 2020.15 This provision shows the impact of post-filing data may extend beyond the patent office.
Post-filing data can be used at the European Patent Office (EPO) to address inventive step rejections and sufficiency rejections, in most circumstances. However, purely speculative applications usually cannot be supported by post-filing data.
The EPO Guidelines for Examination explicitly state “[t]he relevant arguments and evidence to be considered by the examiner for assessing inventive step may either be taken from the originally-filed application or submitted by the applicant during the subsequent proceedings,” but “[c]are must be taken, however, whenever new effects in support of inventive step are referred to. Such new effects can only be taken into account if they are implied by or at least related to the technical problem initially suggested in the originally filed application.”16 Such data can also be used to confirm that the invention does indeed work across the claim scope to address a sufficiency rejection.
Post-filing data are usually used when the specification contains preliminary data and there is a question whether the stated effects are achieved at all and/or across the claim scope. A relatively common example is when the claim is a medical use and the application as filed contains in vitro or animal model data, and then more substantial post-filing data (e.g., human data) are filed during prosecution. Another example is to provide post-filing comparative data to demonstrate an improvement relative to the closest prior art cited by the EPO. A further example is to provide additional exemplification of an effect suggested in the application as filed. For example, the application as filed may suggest an improved drug formulation or sustained release on the basis of initial technical observations, and confirmatory in vivo pharmacokinetic data provided post-filing.
The post-filing data will only be considered if the application as filed makes it plausible or credible that the technical problem is solved by the claimed invention. The data must therefore be related to what is in the application as filed and must confirm what is already predicted or extrapolated from the technical disclosure present in the application as filed. If the post-filing data are completely new and not confirmatory of what was described in the specification as filed, i.e., if the post-filing data provide the first credible evidence that the problem has been solved, then the post-filing data cannot be used.
These principles were established by the EPO Boards of Appeal in cases T939/92 and T1329/04 for inventive step, and T609/02 for sufficiency of disclosure.
Post-filing data are therefore often needed when there is a question regarding the reproducibility of the disclosure across the scope of the claim, or when there is a question of possible non-working embodiments. The Enlarged Board of Appeal, in case G1/03, explained that when a claim contains the technical effect—for example a medical use claim wherein the effect of treating the indication is a functional technical feature of the claim—then the claim is limited to embodiments that work so there is no problem under inventive step. For these functionally-limited claims, the question of reproducibility must therefore be considered under sufficiency of disclosure. The question is whether the invention does indeed work as claimed, and confirmatory post-filing data can be used to answer that question provided that the claimed invention is at least plausible from the specification as filed.
Conversely, for a claim without a functional limitation, for example a product claim defined only by structural features—e.g., a Markush definition of a genus of compounds—then the assessment of potential non-working embodiments must be assessed under inventive step. The question here is whether substantially all embodiments within the claim scope provide the stated improvement and, again, post-filing data can be used to confirm a valid extrapolation from the technical disclosure that is present in the application as filed.
Finally, there is no requirement that post-filing data must be submitted to the EPO in a declaration. However, a technical declaration prepared by an expert in the technical field may be more effective than attorney argument in presenting the post-filing data to the examiners for review.
The Japan Patent Office’s Examination Guidelines state that as a response to the notice of reason for refusal on an inventive step, the applicant may make a rebuttal statement by submitting post-filing data in a certificate of experimental results.17 However, the Guidelines also state that a certificate of experimental results is no substitute for “Detailed Description of the Invention” in the as-filed application.18 The submission of the certificate of experimental results is permitted only for the applicant to clarify or verify that matters stated in the originally-attached description are correct and reasonable.
In a decision of July 15, 2010, Heisei 21 (Gyo KE) No. 10238 (Japan), the Intellectual Property High Court ruled that if there are statements sufficient for a person ordinarily skilled in the art to recognize the “effect of the invention” in the as-filed application or if there are statements on which a person ordinarily skilled in the art can infer the “effect of the invention,” it should be permitted to take into account an experiment result that has been supplemented after the filing of the application unless such result goes beyond the scope of such statements, acknowledging the patentability of the invention in consideration of the contents of the certificate of experimental results.19
In addition, the JPO’s Examination Guidelines also state that the examiner may consider post-filing circumstances such as commercial success as a secondary consideration for supporting the existence of an inventive step.20
Further, the JPO’s Examination Guidelines state that as a response to the notice of reason for refusal on enablement and written description requirements, the applicant may make a rebuttal statement by submitting post-filing data in a certificate of experimental results.
For example, the applicant may make an argument in a written opinion, pointing out the common general knowledge at the time of filing other than one taken into account by the examiner when making the determination, and arguing that, in light of such common general knowledge, the details provided in the description can be expanded or generalized to the scope of the claimed invention, and may submit a certificate of experimental results to support such an argument.21
However, as mentioned above, a certificate of experimental results is not a substitute for “Detailed Description of the Invention” in the description. When details provided in the description can neither be expanded nor generalized to the scope of the claimed invention even in light of the common general knowledge at the time of filing, a certificate of experimental results after filing of the application cannot be used to make up for such deficiency (e.g., case on the action to seek rescission of the JPO decision to revoke the patent, Decision by the Intellectual Property High Court, Grand Panel, November 11, 2005 [Heisei 17 (Gyo KE) No. 10042] (Japan), “Manufacturing Method of Polarizing Film”).22
In general, the Japan Patent Office is reluctant to accept post-filing data when considering the inventive step or sufficiency of the claimed invention as compared to other jurisdictions. However, presenting post-filing data may be an effective way to establish the patentability of the claimed invention in Japan, and should always be considered as an option.
In the Republic of Korea, the Korean Intellectual Property Office (KIPO) accepts post-filing evidence for overcoming a rejection based on lack of inventive step but is less likely to accept post-filing evidence to overcome a rejection based on insufficient description. Under Korean patent practice, an applicant may submit post-filing data such as experimental data to demonstrate or support the inventive step of the claimed invention to enhance the chances of overcoming the rejection. The applicant may submit such data, either voluntarily or upon request of a KIPO examiner, as long as the effect or the acts related to the post-filing data are described in the specification, or they can be understood from the specification by a person of ordinary skill in the art.
On the other hand, if the issue relates to the sufficiency of description such as enablement or support in the specification, post-filing data is less likely to be helpful due to KIPO’s strict requirement that the claimed invention be enabled or supported by the specification as originally filed. In this case, the addition of data to the specification by a later amendment would not be allowed as adding new matter, unless the data (e.g., numerical values) could be clearly understood or otherwise recognized from the specification by a person skilled in the art. Thus, submission of post-filing data in response to a rejection based on a defect in the specification generally would not be accepted in KIPO. For example, for an invention directed to a medical use, Korean courts and KIPO require an originally-filed specification to include pharmacological data demonstrating the medical use, unless a pharmacological mechanism underlying the medical use has already been established. Lack of such data in the originally-filed specification cannot be cured by post-filing data.
There are no principles outlined in India's guidelines or manual of the Indian Patent Office (IPO) for acceptance or rejection of post-filing data in general. Also, there is no consistent line of judicial precedents that have conclusively dealt with the issue of considering post-filing data. Thus, such data's acceptability is at the discretion of the Controller, and there is no uniformity among Controllers at the Indian IPO.
The issue of post-filing data for the purpose of establishing inventive step has specifically come to be considered at the Intellectual Property Appellate Board (IPAB) level on two occasions23, and in both situations the interpretation by the IPAB has been that the Patents Act, 1970 does not allow for such data to be considered to establish inventive step. The IPAB while analyzing the submissions in support of post-filing data held that under the Patents Act, 1970, a patent is revoked if the invention is shown to be obvious and such a conclusion cannot be altered by relying upon any secondary considerations.
Recently, the Hon’ble Delhi High Court in the case of Astrazeneca AB & Anr. v. Intas Pharmaceutical Ltd.24 opined on the issue of admissibility of post-filing data in support of inventive step while considering the issue of grant of an interim injunction pending trial of the suit. Following the precedent of Generics (UK) Ltd. v. Yeda Research & Development Co. Ltd., (2017) EWHC 2629 (Pat) (U.K.), relied upon by the Defendants to challenge the validity of patent-in-suit for lack of inventive step, the Court observed prima facie that post priority date evidence furnished by way of an affidavit by plaintiffs to demonstrate technical advance can only be taken into account to confirm the existence of technical effect disclosed in the specification of the patent that is capable of being understood by a skilled person having common general knowledge. The Court held that this evidence cannot be relied upon to establish its effect for the first time. The Single Judge observed that the plaintiffs were unable to demonstrate, at least at the interim stage, the existence of such technical effect in the specification. The Court noted that the plaintiffs' argument that the examiner should have been conscious of the inventive step objection or that evidence of technical advance could be placed before the Court even at this juncture fails to take into account the plain language of Section 64(1)(f)25 read with Section 2(1)(ja)26 of the Patents Act, 1970 (India). The Court observed that the Defendants are entitled to submit, in support of their challenge, that there is no demonstrable technical advance as on the date of priority of the patent-in-suit. This order is currently under challenge in appeal and pending adjudication before the Division Bench (2 Judges) of the Hon’ble Delhi High Court.
An Indian IPO examiner typically considers whether there is a link between the data disclosed in the as-filed application and the post-filing data when determining whether to accept the post-filing data. The examiner will likely refuse to examine the post-filing data if they are largely divergent from the disclosure made in the specification, or there exists a gap or a lack of a link between the data and the disclosure in the specification. On the other hand, if the data are to demonstrate the accuracy of the disclosure made in the specification, and thereby establish that the results indicated therein were unexpected and not contemplated in the prior art references cited by the patent office, it is possible to persuade the patent office to admit the said data.
Mexican patent law provides that the description of the invention has to disclose the invention in a sufficiently clear and complete way to allow a person with average skill in the art to make it, and the best method known to the applicant of carrying out the invention, as well as the necessary information to support the industrial application of the invention.
On the other hand, Mexican patent law does not require experimental evidence covering every embodiment within the scope of a claim, and therefore, the claims should be considered as commensurate in scope with a reasonable generalization of the disclosed examples.
Nevertheless, in practice, when an application does not include experimental evidence for all the claimed subject matter, examiners sometimes raise sufficiency of disclosure, clarity, support and/or inventive step objections. Particularly, the examiners tend to argue that the disclosure is not sufficiently complete and/or it does not contain the best-known method to perform the invention, and the inventive step cannot be recognized because the experimental evidence provided in the application does not support the alleged technical effect.
When these objections are raised, even though the patent law does not include any provision about post-filing data submission, under the local practice, post-filing data is normally accepted as long as such evidence is filed along with the response to the substantive office action and when the alleged technical effect is expressly disclosed in, or can be inferred or derivable from, the originally filed application; however because there is no precedent case law, such as jurisprudence, regulations or guidelines about this issue in Mexico, the acceptance thereof would depend on the examiner overseeing examination of the application.
In the United States, post-filing data are generally acceptable by the United States Patent and Trademark Office (USPTO). Post-filing data can be used to show inventive step (non-obviousness), for example, unexpected results, commercial success, or long felt but unresolved needs. To be considered for “inventive step,” the applicant must show there is a nexus between evidence of the non-obviousness and the claimed invention.27
In the USPTO, post-filing data can be submitted to show enablement. For example, an application filed with prophetic examples describing experiments to be conducted with results not yet available at filing. The applicant can then submit data after filing to demonstrate that the claims are enabled. In Amgen Inc. v. Hoechst Marion Roussel, the claims were construed more broadly than the prophetic example disclosed in the specification. In finding the claims were enabled, the Amgen Court looked not only to the disclosure providing the prerequisite method of making and using the invention, but also considered post-filing evidence from Amgen, which further demonstrated an enabling disclosure as of the time of filing.28
Notably, post-filing data must be submitted in the form of a declaration signed by an inventor or a person qualified in the relevant technical field.
When it is not possible to include all the relevant data at filing, data generated after filing may still be submitted during prosecution. As discussed above, jurisdictions differ on whether and how post-filing data can be used: some explicitly require the examiner to consider post-filing data; others are silent, leaving it to the discretion of the examiners entirely. These country-to-country variations will affect the prospect of obtaining enforceable claims in these jurisdictions, which can be a crucial consideration when considering which countries to enter when converting a PCT application.
On the other hand, despite the differences among the jurisdictions, the common trend is that the examiners are more willing to accept the post-filing data when considering the inventive step of the claims rather than the sufficiency of disclosure (written description and enablement). Therefore, IP counsel should pay particular attention to any potential sufficiency of disclosure issues and communicate with the inventors to properly address such issues prior to filing. In addition, examiners are more receptive to post-filing data if they can be derived from the as-filed application or if the effect that the data are relied on to prove is disclosed in the as-filed application. Therefore, even if data are not available at filing, IP counsel should describe the technical effects and the methods for the determination thereof in the application to provide a clear basis for post-filing data. It is also advisable to include prophetic examples, including contemplated animal models, clinical trial data, and the like, to increase the chance these data, if and when available, can be admitted for examination.
Balancing the need of filing early to avoid anticipatory prior art, and filing an application with sufficient support to avoid rejections requires careful consideration and planning from a company’s research and development, clinical and legal teams. Knowledge of the treatment of the post-filing data in different jurisdictions is crucial to devising a robust and efficient global patent strategy.
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