DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendments
Applicant's duplicate claim set filed 8/18/2025 has been entered. No claims have been canceled, added or amended. Claims 1-12 remain pending and are being considered on their merits. References not included with this Office action can be found in a prior action. Any rejections of record not particularly addressed below are withdrawn in light of the claim amendments and applicant’s comments.
All of the rejections below are identical to those in the Office Action mailed 5/16/2025.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-5 and 7-11 remain rejected under 35 U.S.C. 103 as being unpatentable over Ray (U.S. PGPUB 2011/0014251) in view of Rocha et al (2014, J. Proteome Res., 13: 1045-1054; plus Supplemental), Wu et al (2013, J. Cell. Physiol. 228: 938–944) and Colombo et al (2014, Annu. Rev. Cell Dev. Biol., 30:255–89).
Regarding claims 1, 5, 7 and 11, Ray teaches that “microvesicles" are also known as "exosomes" (see paragraph [0056]), and that microvesicles are useful for treatment of diseases and for tissue repair via injection to the target tissue in mammals (see paragraphs [0018], [0019], [0221] and [0222]). Regarding claims 1 and 7, Ray teaches that the microvesicles can be collected from specific cell types that are differentiated from stem cells and thereby used to target specific tissues for repair or regeneration (see Table 1). Regarding claims 1 and 7, Ray teaches that examples of tissues that may be treated include cartilage (see paragraphs [0114] and [0125]). Regarding claims 1, 3, 4, 7, 9 and 10, Ray teaches that the stem cells which may be differentiated can be any of several types of stem cells, including both embryonic stem cells, adult stem cells, and specifically mesenchymal stem cells from different tissues (see paragraphs [0016] and [0189]). Regarding claims 4 and 10, Ray teaches that the cells are preferably human cells (see paragraphs [0164], [0192] and [0203]).
Ray does not teach that the exosomes are isolated from adipose-derived stem cells differentiating into chondrocytes having precartilage condensation, comprising the surface markers in claims 2 and 8, and not being fully differentiated.
Regarding claims 1 and 7, Rocha teaches that inducing cells derived from bone marrow mesenchymal stem cells to differentiate toward chondrocytes involves inducing chondrogenic condensation (see pages 1045 and 1052; reads on “precartilage condensation”). Regarding claims 1, 2, 7 and 8, Rocha teaches that material secreted from cells derived from bone marrow mesenchymal stem cells triggered to differentiate toward chondrocytes contains several factors that are needed for cartilage formation, including markers of cartilage development such as versican, along with CD63, CD81, FLOT1 and ANXA5, and have therapeutic potential for the repair of cartilage (see abstract and pages 1050-1051 and Supplemental Table 1).
Regarding claims 1, 4, 7 and 10, Wu teaches that due to the large numbers of cells that can be harvested with relatively little donor morbidity, adipose-derived stem cells are considered to be an attractive alternative to bone marrow derived mesenchymal stem cells (see abstract). Regarding claims 1, 4, 7 and 10, Wu teaches adipose tissue derived mesenchymal stem cells (ASCs) are useful for differentiation into chondrocytes and that there is increased cartilage formation by co-culture of ASCs with chondrocytes (see abstract). Regarding claims 1, 3, 7 and 9, Wu teaches once ASCs are committed to the chondrogenic lineage, they begin expressing many components important for cartilage formation (see page 940).
Regarding claims 1, 2, 7 and 8, Colombo teaches that ALIX and TSG101 are proteins associated with microvesicles (see page 269), and that ICAM1 and EpCAM can be found on microvesicles (see pages 265 and 277).
It would have been obvious to combine Ray with Rocha, Wu and Colombo to use exosomes are derived from ASCs differentiating into chondrocytes, and displaying precartilage condensation, to treat cartilage in Ray’s method. A person of ordinary skill in the art would have had a reasonable expectation of success in using exosomes are derived from ASCs differentiating into chondrocytes, and displaying precartilage condensation, to treat cartilage in Ray’s method because Ray teaches that exosomes from differentiated stem cells are useful for treating tissues including cartilage, and Wu establishes that once ASCs are committed to the chondrogenic lineage, they begin expressing many components important for cartilage formation. Additionally, Rocha establishes that stem cells undergoing chondrogenic differentiation display chondrogenic condensation (reads on “precartilage condensation”) and express CD63, CD81, FLOT1 and ANXA5, while Colombo teaches that ALIX and TSG101 are proteins associated with microvesicles, and that ICAM1 and EpCAM can be found on microvesicles. The skilled artisan would have been motivated to use exosomes are derived from ASCs differentiating into chondrocytes, and displaying precartilage condensation, to treat cartilage in Ray’s method because Rocha teaches that such cellular secretions from differentiating bone marrow derived mesenchymal stem cells contains several factors that are needed for cartilage formation while Colombo teaches important factors identified by Rocha are found in extracellular vesicles, and Wu establishes that ASCs are attractive alternative to bone marrow derived mesenchymal stem cells. Additionally, Rocha establishes that stem cells undergoing chondrogenic differentiation display chondrogenic condensation (reads on “precartilage condensation”).
It would have been obvious to combine Ray with Rocha, Wu and Colombo to use exosomes expressing CD63, CD81, ALIX, FLOT1, ICAM1, EpCam, ANXA5 and TSG101. A person of ordinary skill in the art would have had a reasonable expectation of success in using exosomes with the claimed markers because while the references are silent as to the markers on the exosomes, the exosomes of Ray in view of Rocha and Wu are made by the same method as the exosomes used in the claims, and they are useful for the same purpose as the exosomes in the claims. Additionally, Rocha establishes that stem cells undergoing chondrogenic differentiation express CD63, CD81, FLOT1 and ANXA5, and Colombo teaches that ALIX and TSG101 are proteins associated with microvesicles, and that ICAM1 and EpCAM can be found on microvesicles. The skilled artisan would have been motivated to use exosomes that are derived from ASCs differentiating into chondrocytes in Ray’s method because Rocha teaches that such cellular secretions from differentiating bone marrow derived mesenchymal stem cells contains several factors that are needed for cartilage formation while Colombo teaches important factors identified by Rocha are found in extracellular vesicles, and Wu establishes that ASCs are attractive alternative to bone marrow derived mesenchymal stem cells. Therefore the cited art taken as a whole demonstrates a reasonable probability that the exosomes made by the method Ray with Rocha, Wu and Colombo appear to be either identical or sufficiently similar to the claimed exosomes that whatever differences exist are not patentably significant. Therefore, the burden of establishing novelty or unobviousness by objective evidence is shifted to applicants.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill at the time the invention was made.
Claims 6 and 12 remain rejected under 35 U.S.C. 103 as being unpatentable over Ray (U.S. PGPUB 2011/0014251) in view of Rocha et al (2014, J. Proteome Res., 13: 1045-1054), Wu et al (2013, J. Cell. Physiol. 228: 938–944) and Colombo et al (2014, Annu. Rev. Cell Dev. Biol., 30:255–89) as applied to claims 1-5 and 7-11 above, and further in view of Pietrzkowski (U.S. PGPUB 2011/0275078).
The teachings of Ray in view of Rocha, Wu and Colombo are discussed and relied upon above.
Ray does not teach that the concentration of exosomes in the treatment is 1 to 1000 micrograms per milliliter.
Regarding claims 6 and 12, Pietrzkowski teaches that doses of treatments of exosomes can be 1 to 1000 micrograms per milliliter (see paragraph [0054]).
It would have been obvious to combine Ray in view of Rocha with Pietrzkowski to use a dose of 1 to 1000 micrograms per milliliter of exosomes in Ray’s treatment method. A person of ordinary skill in the art would have had a reasonable expectation of success in using a dose of 1 to 1000 micrograms per milliliter in Ray’s method because Pietrzkowski teaches that these doses are suitable for treatments. The skilled artisan would have been motivated to use a dose of 1 to 1000 micrograms per milliliter in Ray’s method because Pietrzkowski teaches that these doses are suitable for treatments.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill at the time the invention was made.
Response to Arguments
Applicant's arguments filed 8/18/2025 have been fully considered but they are not persuasive.
Applicant again highlights that Ray does not exemplify using stem cells that are differentiating into chondrocytes, noting that Ray exemplifies neuronal differentiation. However, as stated in the rejection, Ray teaches that “microvesicles" are also known as "exosomes", and Ray teaches that the microvesicles can be collected from stem cells differentiated into specific cell types matching the target tissue in order to target specific tissues for repair or regeneration, and that the treated tissue may be cartilage (see Table 1, paragraphs [0056], [0114] and [0125] as cited above). Therefore, since chondrocytes are cartilage cells, Ray does provide teaching and motivation to use stem cells differentiating into chondrocytes as the source of microvesicles/exosomes to treat cartilage tissue. Additionally, it is the other secondary references that provide further specific motivation to use exosomes from stem cells that are differentiating into chondrocytes as both Wu and Rocha establish that once stem cells are committed to the chondrogenic lineage, they begin expressing many components important for cartilage formation, and both Rocha and Colombo establish that these components are associated with secreted microvesicles. Therefore, the combination of referernces render it obvious to use exosomes from stem cells that are differentiating into chondrocytes to treat cartilage tissue and this argument is not persuasive.
Applicant acknowledges that Ray explicitly states that their “microvesicles” are also called “exosomes”, but alleges that Ray’s microvesicles are not exosomes. To support this position, applicant points to publications by Colombo and Stahl, noting that these publications use the terms “microvesicles” and “exosomes” to refer to different membrane bound vesicles, originating from different parts of a cell prior to being secreted. Applicant also notes that Ray cites a publication by Aliotta, noting that Aliotta only uses the term “microvesicles” and not “exosomes”. Applicant concludes that Ray does not teach “exosomes” as claimed. However, the instant specification provides the following definition of “exosomes” in the paragraph spanning pages 5 and 6:
As used herein, the term “exosome” refers to a vesicle surrounded by a membrane, which can be secreted from various types of cells. An exosome can carry out various roles such as transferring materials from first cells and tissues to second cells and tissues by binding to the second cells and tissues. The materials transferred by an exosome may include any of membrane components, proteins, and ribonucleic acid (RNA). (Emphasis added).
Therefore, as the instant specification specifically defines “exosome” as “a vesicle surrounded by a membrane, which can be secreted from various types of cells”, this is the definition applied to the term “exosome” in the instant claims. In other words, the claims are not limited to only exosomes as more narrowly defined by Colombo and Stahl, and therefore Ray’s membrane bound microvesicles secreted from cells do read on the claimed “exosomes”. Additionally, while applicant notes that Ray cites a publication by Aliotta, noting that Aliotta only uses the term “microvesicles” and not “exosomes”, this publication does not provide any reasons to conclude that Ray’s “microvesicles”, which Ray states are also called “exosomes”, do not read on the instantly claimed exosomes as defined in the instant specification.
Applicant continues to allege that Ray’s term “microvesicles” are not “exosomes” because Ray isolation method uses ultracentrifugation at 25,000 rpm for 3 hours, alleging that “[t]hese separation conditions and speeds differ significantly from those commonly used for isolating exosomes, which typically require ultracentrifugation at >100,000xg and yield vesicles ranging from 30 to 100 nm in size”. First, it is noted that applicant does not provide any citation to support their alleged “commonly used for isolating exosomes”, and this statement appears to simply be the opinion of applicant’s representative. Importantly, the instant specification does not provide any guidance as to what centrifugation conditions are needed to isolate exosomes. The only example in the instant specification of exosome isolation uses centrifugation “at 10000×g for 60 minutes to obtain an exosome precipitate, which was then filtered through a 0.22 μm filter” (Example 1), which is very different from what applicant’s representative alleges are “commonly used for isolating exosomes”. Furthermore, while the specification does not define the size of exosomes, the use of a 0.22 μm filter would allow for vesicles with sizes up to 220 nm to be included, which is also larger than what applicant’s representative alleges are vesicle sizes of exosomes. In other words, applicant’s representative’s opinion is not in line with the examples in the instant specification. Finally, the Ray reference specifically defines their microvesicles as typically having a size of “about 30 to about 90 nm in diameter” (see Ray at paragraph [0056]), which overlaps with the diameter of “30 to 100 nm” applicant’s representative alleges is the size of exosomes. Therefore, for any of these reasons, Ray’s isolation method does not support applicant’s position that Ray does not teach exosomes as claimed, and this argument is not persuasive.
Applicant alleges that the Roche reference is interested in the secretome of and not in the contents of exosomes. However, as the rejection of record states, the primary reference Ray is relied upon for the teachings of making and using a treatment composition of exosomes while the secondary Roche reference was relied upon for teaching that material secreted from cells derived from bone marrow mesenchymal stem cells triggered to differentiate toward chondrocytes contains several factors that are needed for cartilage formation and have therapeutic potential for the repair of cartilage. While applicant also appears to allege that Roche’s secretome analysis does not include materials in exosomes, this is not the case. Even the highlighted method of Roche copied into the applicant’s reply states that their method “diminishes the detection of cell lysis-derived proteins” (see applicant’s reply at page 9 and Roche at col. 1 on page 1051). Applicant is reminded that exosomes are secreted from cells, and, as noted by applicant, Roche is specifically interested in what proteins are secreted from cells. Therefore, suggesting that Roche is not interested in proteins secreted in exosomes is contradictory to the purpose of Roche. Furthermore, the rejection also highlights that Colombo teaches at least some of the factors identified by Rocha are found in extracellular vesicles. Therefore this argument is not persuasive.
Applicant alleges that they have demonstrated surprising effects achieved by embodiments of the present application, pointing to Examples 1-3 in Figures 5 and 6 of the instant specification. Figure 5 shows the effects of exosomes derived from ASC and exosomes derived from ASC differentiating into chondrocytes. Applicant concludes that this figure shows that exosomes from ASC differentiating into chondrocytes showed enhanced stimulation of chondrocyte differentiation. However, it is unclear how this figure shows any difference between the two treatment groups as each of the conditions appear to show the same result. Importantly, it is unclear how applicant is alleging that enhanced stimulation of chondrocyte differentiation is “unexpected” as the art specifically teaches that exosomes secreted from differentiating into chondrocytes comprise factors that are known to stimulate chondrocyte differentiation. In other words, this result is expected based on the cited prior art. Applicant also alleges that Figure 6 shows that ASC derived exosomes resulted enhanced chondrocyte differentiation as compared to BM derived exosomes. However, again, it is unclear how these images show any difference between the treatment groups as each of the conditions appear to show the same result. While applicant includes a graph to quantify the images, the graph indicates that both the ASC exosomes and the BM exosomes stimulated chondrocyte differentiation. Applicant does not include error bars or any explanation of the quantification in the graph and therefore it is unclear if the different levels of stimulation are significant, especially as all of the conditions resulted in lower levels of chondrocyte differentiation as compared to the use of a differentiation medium lacking exosomes. Furthermore, the rejection above specifically addresses the obviousness to use exosomes from ACS, and that ACS are preferred to BM. The primary reference Ray specifically teaches using exosomes from stem cells from various tissue sources and the rejection above specifically highlights that it was predicted that exosomes from ASCs would be useful for treating cartilage. Therefore, again, as the art specifically teaches that exosomes secreted from differentiating into chondrocytes comprise factors that are known to stimulate chondrocyte differentiation, the results in the specification are not sufficient to establish unexpected results of stimulation of chondrocyte differentiation, and this argument is not persuasive.
Applicant alleges that the other secondary references to not remedy the alleged deficiencies above. However, as applicant’s alleged deficiencies were not persuasive, this argument is not persuasive.
Conclusion
No claims are free of the art. No claims are allowed.
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 nonprovisional extension fee (37 CFR 1.17(a)) 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.
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/S.A.M/ Examiner, Art Unit 1653 /SHARMILA G LANDAU/Supervisory Patent Examiner, Art Unit 1653
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