Patent Profile: DermTech Receives Patent for Method of Detecting Melanoma in Human Subjects

By Josh Bosman --

The U.S. Patent and Trademark Office recently issued a notice of allowance for U.S. Application No. 14/199,900, which is entitled "Diagnosis of Solar Lentigo by Nucleic Acid Analysis."  The '900 application, which is assigned to the DermTech International, contains claims to a method of detecting melanoma in a human subject.  DermTech is a San Diego-based biotechnology company developing and commercializing gene expression tests to facilitate the diagnosis of dermatologic conditions.

Melanoma is the most serious type of skin cancer, but can be treated successfully if it is detected early.  Most melanoma deaths can be prevented by surgical excision if they are detected in their early stages.  The methods of the '900 application help to enable physicians to determine the nature and extent of suspicious lesions of the skin by providing accurate, objective information to the physicians to improve care while reducing costs.  More specifically, DermTech's technology allows the analysis of skin samples collected non-invasively using an adhesive patch.

The '900 application has two independent claims which recite:

Claim 1.    A method of detecting melanoma in a human subject comprising:
    (a) obtaining a sample of a skin lesion suspected of comprising melanoma from a human subject, wherein the skin lesion sample comprises or is suspected of comprising a nucleic acid molecule expressed from C6orf218;
    (b) detecting the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample, whereby the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample in an amount that is greater than the presence of C6orf218 in a non-melanoma sample is indicative of melanoma in the skin lesion sample, wherein detecting the presence of a nucleic acid molecule expressed from C6orf218 is by application of a detectably labeled probe that hybridizes to a nucleic acid molecule expressed from C6orf218; and
    (c) characterizing the skin lesion as having melanoma or not having.

Claim 15.    A method for diagnosing melanoma in a subject, comprising:
    (a) obtaining a sample of a skin lesion suspected of comprising melanoma from a subject, wherein the skin lesion sample comprises or is suspected of comprising a nucleic acid molecule expressed from C6orf218;
    (b) detecting the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample, wherein detecting the presence of a nucleic acid molecule expressed fromC6orf218 is by application of a detectably labeled probe that hybridizes to a nucleic acid molecule expressed from C6orf218; and
    (c) comparing the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample to the presence of C6orf218 in a non-melanoma sample, whereby the increased presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample as compared to the non-melanoma sample is indicative of melanoma, thereby diagnosing the skin lesion as having melanoma.

A review of the file history of the `900 application (examined under Track I) indicates a rejection under 35 U.S.C. § 101 was issued (along with rejections under §§ 112, 102, and 103) in the first Office Action, mailed December 10, 2014.  The Action stated that the claimed invention was directed to patent ineligible subject matter.  Specifically, the Action asserted that the claims were directed to a natural correlation or a natural principle (i.e., the claims reflect the natural correspondence between gene expression and melanoma).  Furthermore, the Action asserted that the claimed methods failed to incorporate steps that amount to significantly more than the natural principles themselves because the steps merely incorporate conventional, routine techniques while failing to incorporate some other inventive concept.

In response, with respect to the 101 rejection, the Applicant argued that the claims, as amended, are patent eligible because the amended claims do not seek to tie up the use of C6orf218, and others are not excluded from using C6orf218 or C6orf218 expression products in other ways that do not utilize the claimed methods for detecting or diagnosing melanoma.  Furthermore, the Applicant argued that the claims as amended are not directed to a judicial exception because the claims are directed to methods of using "a detectably labeled probe that hybridizes to a nucleic acid molecule expressed from C6orf218" and to determine the presence of C6orf218 for "detecting melanoma in a human subject" or for "diagnosing melanoma in a subject".

Finally, the Applicant argued that the amended claims recite an inventive concept because claims 1 and 15, provide methods for "detecting melanoma in a human subject" or for "diagnosing melanoma in a subject," by "detecting the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample," which, according to the Applicant, is not taught, alone or in combination, by the art cited in the Action.

Claims 1 and 15 as amended recited:

Claim 1.    A method of detecting distinguishing melanoma from dysplastic nevi or normal pigmented skin in a human subject comprising:
    (a) obtaining a sample of a skin lesion suspected of comprising melanoma from a human subject, wherein the skin lesion sample comprises or is suspected of comprising a nucleic acid molecule expressed from C6orf218;
    (b) detecting the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample, whereby the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample in an amount that is greater than the presence of C6orf218 in a non-melanoma sample is indicative of melanoma in the skin lesion sample, wherein detecting the presence of a nucleic acid molecule expressed from C6orf218 is by application of a detectably labeled probe that hybridizes to a nucleic acid molecule expressed from C6orf218analyzing expression of a nucleic acid molecule encoded by C6orf218; and
    (c) characterizing the skin lesion as having being melanoma or not having ,dysplastic nevi, or normal pigmented skin, thereby distinguishing melanoma from dysplastic nevi or normal pigmented skin in a human subject.

Claim 15.    A method for diagnosing melanoma in a subject, comprising:
    (a) obtaining a sample of a skin lesion suspected of comprising melanoma from a subject, wherein the skin lesion sample comprises or is suspected of comprising a nucleic acid molecule expressed from C6orf218;
    (b) detecting the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample, wherein detecting the presence of a nucleic acid molecule expressed fromC6orf218 is by application of a detectably labeled probe that hybridizes to a nucleic acid molecule expressed from C6orf218; and
    (c) comparing the presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample to the presence of C6orf218 in a non-melanoma sample, whereby the increased presence of a nucleic acid molecule expressed from C6orf218 in the skin lesion sample as compared to the non-melanoma sample is indicative of melanoma, thereby diagnosising the skin lesion as having melanoma providing a gene expression profile of a target area suspected of being melanoma on the skin of the subject; and
(b) analyzing the subject's gene expression profile with respect to a reference gene expression profile obtained from a corresponding normal skin sample, wherein the reference gene expression profile comprises an expression value of a target gene that is C6orf218.

The file history indicates that a search was performed by the Examiner following the Applicant's response, but the notice of allowance mailed on March 30, 2015 provides no additional comments concerning the allowability of the claims other than noting that the application is in condition for allowance.

Comments

[Greg DeLassus]

Well, the "obtaining a sample of a skin lesion" step certainly ensures that no one will complain that you can "do it all in your head."

I see that this is pre-AIA patent, so it cannot be challenged in PGR. I guess, therefore, that if its 101 soundness is to be challenged, it will be a while before the occasion can present itself. We will have to wait and see.

[Paul F. Morgan]

Was not there considerable hyperbole in some prior comments on this blog that the Sup. Ct. had rendered all medical diagnostic test methods unpatentable, especially those involving human genetic material?

[GD]

Arguing non-obviousness in a 101 rejection is just beyond bizarre. Still can't get the 'ole brain wrapped around that incoherence. Maybe more coffee will help . . . maybe not.

[Greg Zornetzer]

Greg L: as with pretty much any biological test, there must be some physical action, so "do it all in your head" isn't truly the problem here. However, if one considers the association between an elevated C6orf218 and high likelihood of melanoma to be a law of nature, then collecting a skin sample and running a test for elevated C6orf218 would seem to be a trivial application of that natural law.
I'm guessing that Dermtech has other patent(s) that cover the process of obtaining and processing the skin sample (if they are/were indeed novel), and methods for measuring nucleic acid levels from biological samples are well known in the art.
This would seem to be on shaky ground after Mayo v Prometheus.

[Greg DeLassus]

This would seem to be on shaky ground after Mayo v Prometheus.

I do not disagree. I do not think that this claim should be on shaky ground, but it probably is.

As for the "do it all in one's head," see the In re BRCA-1 Cancer Test opinion for an example of a biological test that was disparaged as a purely mental operation.

[Skeptical]

Any - and every - claim can be made to fail if one allows elements of the claim to be removed as if they did not exist (for any reason).

This applies to:
field of use,
"old" elements,
elements traditional to the field,
elements necessary for other actions,
elements of mental steps, and
elements sounding in "function."

Once you jump on the slippery slope of "what is the claim REALLY to" while parsing out elements of the claim as if they don't exist (no matter how "pretty" the language, i.e., "directed to"), you cannot stop the slide to the bottom.

[Kevin E. Noonan]

Paul: as you well know, getting a patent and enforcing it are two different things. We will need a bit more time and experience before anyone can determine whether what has been written on this blog was hyperbole. Although I hope in fact that it will turn out that way.