Prosecution Insights
Last updated: April 19, 2026
Application No. 17/768,409

Beta-hydroxybutyrate Salt Granule and Methods for Producing the Same

Final Rejection §103
Filed
Apr 12, 2022
Examiner
PURDY, KYLE A
Art Unit
1611
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Nanjing Nutrabuilding Bio-Tech Co. Ltd.
OA Round
4 (Final)
41%
Grant Probability
Moderate
5-6
OA Rounds
4y 0m
To Grant
78%
With Interview

Examiner Intelligence

Grants 41% of resolved cases
41%
Career Allow Rate
395 granted / 968 resolved
-19.2% vs TC avg
Strong +37% interview lift
Without
With
+36.9%
Interview Lift
resolved cases with interview
Typical timeline
4y 0m
Avg Prosecution
79 currently pending
Career history
1047
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
60.6%
+20.6% vs TC avg
§102
14.8%
-25.2% vs TC avg
§112
14.0%
-26.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 968 resolved cases

Office Action

§103
DETAILED ACTION Status of Application The Examiner acknowledges receipt of the amendments filed on 1/6/2026 wherein claim 1 has been amended. Claims 1-7 are presented for examination on the merits. The following rejections are made. Response to Applicants’ Arguments Applicant’s amendments filed 1/6/2026 overcomes the rejection of claims 1 and 4-7 made by the Examiner under 35 USC 103 over Cavaleri (US 2017/0290792) in view of Rourke et al. (US 2011/0111027). This rejection has been withdrawn so as to provide an evidentiary teaching that BHB is hygroscopic. Applicant’s amendments/arguments filed 9/16/2025 overcomes the rejection of claims 2-4 made by the Examiner under 35 USC 103 over Cavaleri (US 2017/0290792) in view of Rourke et al. (US 2011/0111027) further in view of Li et al. (CN 104940181). This rejection has been withdrawn for the reason noted under section 3. New Rejections Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 1 and 4-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cavaleri (US 2017/0290792; of record) in view of Rourke et al. (US 2011/0111027; of record), evidenced by 3-hydroxybutyric acid sodium salt safety data sheet. Cavaleri describes a composition that may be in the form of a dry granule/powder (see [0024, 0028, 0029]) the composition comprising a beta-hydroxybutyrate salt such as magnesium beta-hydroxybutyrate (a BHB metal salt) (see claim 1) (see instant claims 1, 4 and 5) and an excipient such as binders, e.g. hydroxypropyl methylcellulose, and fillers, e.g. starch (see [0027]) (see instant claims 1 and 6). It is noted that both hydroxypropyl methylcellulose and starch are identified by instant claim 6 as a ‘filler’. Thus, a granule comprising a BHB metal salt and a filler would have been readily envisaged thereby anticipating the instant claim. Regarding instant claim 7, the limitation that the composition be ‘for promoting and/or sustaining ketosis in a mammal’ is considered an outcome of the composition being administered (an intended use limitation). However, the promoting and/or sustaining ketosis is not a limitation to the composition itself but rather an outcome of using the already described composition. As the limitation adds nothing to the structure of the composition it is not considered limiting to said structure. See MPEP 2111.02 which states that where a patentee defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention, the preamble is not a claim limitation. Cavaleri fails to teach the BHB granule as having a particle size of 10-100 mesh wherein the granule has a moisture content below 3%. Rourke is directed to granulated gamma-hydroxybutyrate (GHB) compositions wherein the GHB is to be in the form of a salt (i.e. sodium oxybate) (see Example 1). The GHB is sized on various mesh screens such that the resulting particles have a particles size of <45-850 microns (see Example 1 and Table 4C). Although Cavaleri is directed to BHB and Rourke is directed to GHB, the structural difference between the two compounds is the location of the hydroxy group. BHB, 3-hydroxybutyric acid, has the structure PNG media_image1.png 96 191 media_image1.png Greyscale whereas GHB, 4-hydroxybutyric acid, has the structure PNG media_image2.png 84 242 media_image2.png Greyscale . It would have been obvious to modify Cavaleri to shape their BHB granules to a size similar to that of the GHB granules described by Rourke with a reasonable expectation for success. Moreover, the selection of the granule/powder particle size in general would be a matter of obviousness, especially when the general framework of having a particulate composition is already described. Identifying a size would be a matter of routine modification/optimization. See MPEP 2144.04(I)(B). See also MPEP 2144.05(II)(A) which states that where the general conditions of a claim are described by the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. Rourke teaches that GHB is hygroscopic and that because of this property Rourke’s composition should be dried and protected such that it contains no water and does not come into contact with water. The presence of water in the composition negatively impacts the properties of the composition e.g. poor dissolution (see [0005]). Example 1 describes a wet-granulation process where GHB granule comprises between 1-2.5% water and a dry-granulation process wherein the process uses no water and results in a granule with less moisture than the wet granulated granule. Figure 1 demonstrate that dry granulated GHB exhibits substantially improved dissolution kinetics relative to wet granulated GHB. Such dry granulated GHB appears to improve absorption dynamics as well (see [0016]). Just as GHB and BHB are similar in chemical structure, the compounds are also similar in their physical properties. BHB is similarly hygroscopic (see safety data sheet for sodium salt of 3-hydroxybutyric acid salt). Thus, as Cavaleri teaches that dry granule (without further parameters) and as it was known that BHB was hygroscopic, which is considered a negative property for dissolution and absorption kinetics, one of ordinary skill in the art would desire to produce a granule containing as little water as possible. As such, if the result was producing a granule having little to no moisture, such as the granule claimed, then that result would have been the product of ordinary skill and common sense rather than one of innovation. Therefore, the invention as a whole is prima facie obvious to one of ordinary skill in the art at the time the invention was filed, as evidenced by the references, especially in absence of evidence to the contrary. Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Cavaleri (US 2017/0290792; of record) in view of Rourke et al. (US 2011/0111027), evidenced by 3-hydroxybutyric acid sodium salt safety data sheet as applied to claims 1 and 4-7 above, and further in view of Li et al. (CN 104940181; of record). Cavaleri teaches that their compositions may comprise 48.6% of the beta hydroxybutyrate magnesium salt (see Example 2). Cavaleri, however, fails to teach a granule comprising 10-99% by weight of the BHB salt and from 1-90% by weight of the filler. Li is directed to pharmaceutical compositions that may be in the form of a granule (see page 3) wherein the composition comprises a drug, such as beta-hydroxybutyrate and its pharmaceutically acceptable salts (see page 3) wherein the beta-hydroxybutyrate is present in the composition in an amount ranging from 0.1-99% by weight of the composition (see page 3) (see instant claims 2 and 3). The pharmaceutical composition of Li is to comprise excipients such as lactose and/or starch (see page 3). Embodiment 1 provides a powder composition which combines beta-hydroxybutyric acid and starch to produce an end use composition which indicates that Li, like Cavaleri, contemplates composition narrowly comprising the active and the filler material. Regarding the concentration of the filler in the composition, this would have been obvious as it would reasonably calculated from the difference of the included beta-hydroxybutyrate salt. That is, if one desired a composition that comprised 40% of the beta-hydroxybutyrate then the remaining 60% could be attributed to the filler material, e.g. starch, lactose, etc.. The claimed filler concentration is also obvious in view of MPEP 2144.05(II)(A) which states that where the general conditions of a claim are described by the prior art (granule composition comprising beta-hydroxybutyrate salt and a filler), it is not inventive to discover optimum or workable ranges by routine experimentation and that it is the normal desire or artisans to improve upon what is already generally known. Therefore, the invention as a whole is prima facie obvious to one of ordinary skill in the art at the time the invention was filed, as evidenced by the references, especially in absence of evidence to the contrary. Conclusion THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KYLE A PURDY whose telephone number is (571)270-3504. The examiner can normally be reached from 9AM to 5PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Bethany Barham, can be reached on 571-272-6175. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). /KYLE A PURDY/Primary Examiner, Art Unit 1611
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Prosecution Timeline

Apr 12, 2022
Application Filed
Jan 21, 2025
Non-Final Rejection — §103
Apr 17, 2025
Response Filed
Jul 14, 2025
Final Rejection — §103
Sep 12, 2025
Applicant Interview (Telephonic)
Sep 15, 2025
Response after Non-Final Action
Oct 07, 2025
Non-Final Rejection — §103
Jan 06, 2026
Response Filed
Mar 25, 2026
Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
41%
Grant Probability
78%
With Interview (+36.9%)
4y 0m
Median Time to Grant
High
PTA Risk
Based on 968 resolved cases by this examiner. Grant probability derived from career allow rate.

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