Scope & Claims Analysis and U.S. Patent Landscape for RAD1901-2HCl Solid Form (US 10,745,343)

US 10,745,343 is a U.S. method-of-treatment patent that ties breast cancer therapy to a specific crystalline/specific solid form of RAD1901-2HCl characterized by low-moisture X-ray powder diffraction (XRPD) peaks at ~0% relative humidity, plus additional identity/quality attributes (DSC melting/transition features and/or TGA). The enforceable claim core is the combination of (i) treating breast cancer and (ii) administering the specified RAD1901-2HCl solid form defined by XRPD peak positions (±0.2° 2θ at ~0% RH), with broadening dependent claim sets that lock in increasing numbers of XRPD peaks and then narrow further to exact peak sets, specific figure-supported XRPD, DSC/TGA profiles, ER+ disease, resistant ER-driven progression post-endocrine therapy, and selected combination regimens and specific ESRD/SERD and endocrine targets plus particular ER LBD mutations.

What does US 10,745,343 claim for RAD1901-2HCl breast cancer treatment?

Answer (claim scope in one line): A method of treating breast cancer using a solid form of RAD1901-2HCl defined by an XRPD fingerprint at ~0% RH with a required 7.1° (2θ ±0.2°) peak, with dependent claims progressively requiring additional peaks and other analytical signatures.

Claim 1: the enforceability anchor

Claim 1 requires:

Treatment: “a method of treating breast cancer”
Administration: to a subject in need thereof
Drug material: “a solid form of RAD1901-2HCl”
Identity by XRPD: the solid form has an XRPD pattern comprising a peak at
- 7.1° 2θ ± 0.2°
- “at about relative humidity 0%”

This makes XRPD at near-dry conditions an explicit claim limitation. For infringement, the accused product’s RAD1901-2HCl solid form must produce an XRPD peak meeting the positional window when tested under substantially similar conditions.

Dependent claims 2–12: XRPD peak-count expansion and exact signature lock-in

These claims progressively add XRPD peak requirements at ~0% RH using ±0.2° windows:

Claim 2: requires XRPD peaks at
- 7.1° ±0.2° and 14.3° ±0.2° at ~0% RH
Claims 3–10: require at least N peaks (N = 1 + extra) by selecting from a recited set of candidate peak positions:
- Candidate peaks (as listed across claims): 11.0, 12.0, 13.8, 14.3, 16.2, 18.3, 18.9, 25.1, 27.2 (all ±0.2° 2θ), plus 7.1° ±0.2° as the baseline peak in claim 1
- Claim 3: at least one additional peak from {14.3, 18.3}
- Claim 4: at least two additional peaks from {14.3, 18.3, 13.8, 12.0}
- Claim 5: at least three additional peaks from {14.3, 18.3, 13.8, 12.0, 25.1, 18.9}
- Claim 6: at least four additional peaks from {14.3, 18.3, 13.8, 12.0, 25.1, 18.9, 27.2, 11.0}
- Claim 7: similar but explicitly includes 16.2° among the selectable set
- Claim 8: at least six peaks from {14.3, 18.3, 13.8, 12.0, 25.1, 18.9, 27.2, 11.0, 16.2}
- Claim 9: at least seven peaks from the same pool
- Claim 10: at least eight peaks from the same pool
Claim 11: locks in the full set of peaks (10 peaks) listed in claim 1/11, all at ~0% RH:
- 7.1, 14.3, 18.3, 13.8, 12.0, 25.1, 18.9, 27.2, 11.0, 16.2 (each ±0.2°)
Claim 12: adds a reference anchor: the XRPD pattern is “as shown in FIG. 4G at about relative humidity 0%”

Practical scope effect: the dependent chain gives the patentee multiple “entry points” for proving identity. Even if an accused solid form is argued to have some peak intensities or minor shifts, the “at least N peaks” scaffolding reduces the chance that the defendant can avoid the claim entirely by making small analytical differences, as long as the required positional windows are met.

Claim 13–15: orthogonal analytical limits (DSC/TGA)

Claim 13: requires a DSC thermogram with:
- melting onset at 218.2°C
- endothermic peak at 232.1°C
Claim 14: requires the DSC thermogram “as shown in the bottom figure of FIG. 8”
Claim 15: requires TGA “as shown in the top graph of FIG. 8”

Scope effect: the claim set can support non-XRPD evidentiary reinforcement and narrows the identity further where DSC/TGA are also required. From an enforcement perspective, multiple tests allow triangulation; from a generic development perspective, it raises product-identity risk if there are polymorph/solvate/hydrate variations.

Claim 16–21: clinical sub-scope (ER+, resistance context, and specific combinations/ER mutations)

Claim 16: breast cancer is ER+
Claim 17: resistant ER-driven cancer that progressed after endocrinological treatment, where endocrinological treatment includes one or more drugs selected from a long list including SERDs, aromatase inhibitors, SERMs, HER2 inhibitors, chemotherapy agents, CDK4/6 inhibitors, mTOR inhibitors, and rituximab.
Claim 18: further defines the SERD and other class selectors by naming multiple agents (examples include fulvestrant; TAS-108BU/SR16234; ZK191703; RU58668; brilanestrant/GDC-0810/ARN-810; etacstil/GW5638/-DPC974; SRN-927; AZD9496). It also enumerates aromatase inhibitors (anastrozole, exemestane, letrozole), SERMs (tamoxifen, raloxifene, lasofoxifene, toremifene), HER2 inhibitors (trastuzumab, lapatinib, ado-trastuzumab emtansine, pertuzumab), and chemotherapy examples (nab-paclitaxel/abraxane; adriamycin; carboplatin; etc.). It lists bevacizumab as an angiogenesis inhibitor in the same dependent claim structure.
Claim 19–20: subject is further administered CDK4/6 inhibitor and/or mTOR inhibitor; list includes palbociclib, ribociclib, abemaciclib, everolimus, or combinations.
Claim 21: breast cancer includes one or more mutant ER binding domains with specified mutations (examples include Y537X1 where X1 = S/N/C; D538G; L536X2 where X2 = R/Q; P535H; V534E; S463P; V392I; E380Q).

Scope effect: claims 16–21 keep the therapy definition tethered to endocrine-resistant biology and specific drug classes/mutations, but the XRPD-defined solid form in claim 1 remains a necessary prerequisite for infringement of the broader methods that incorporate the solid form. These dependent limitations matter for claim selection in litigation and for aligning the clinical label/indication strategy.

How is the XRPD limitation constructed, and why does it matter for infringement?

Answer: The XRPD limitation is a positional diffraction peak constraint measured at ~0% relative humidity with a ±0.2° 2θ tolerance, creating a testable identity boundary for the RAD1901-2HCl solid form.

XRPD peak windows

Primary required peak: 7.1° ±0.2° (2θ)
Additional peaks (as recited): 11.0, 12.0, 13.8, 14.3, 16.2, 18.3, 18.9, 25.1, 27.2 (all ±0.2°)

Peak-count “either/or” structures

The dependent claims use:

“comprising peaks … at least [one/two/three…] peaks” from defined sets
“comprising the peaks” in claim 11, which is stricter because it enumerates the full set.

Litigation implication: “comprising” is favorable to the patentee because it allows additional peaks beyond the recited set. The defendant’s strongest practical route is usually to miss the required positional window(s), not merely to alter crystallinity.

Why “about relative humidity 0%” expands complexity

The requirement is not merely XRPD “at some condition”; it calls out the environmental state. In practice, this becomes:

whether the testing method conditions match the claimed “about 0% RH”
whether the solid form absorbs moisture or interconverts under humidity, potentially shifting peak positions or intensities.

What is the likely crystal/solid-form scope within US 10,745,343?

Answer: The patent covers at least one specific RAD1901-2HCl solid form characterized by a discrete low-humidity XRPD profile, with optional reinforcement by DSC and TGA.

The claim structure strongly suggests:

RAD1901-2HCl has multiple possible solid forms (e.g., polymorphs, solvates, amorphous/partially crystalline forms, or humidity-dependent forms)
the claimed invention is a particular form that yields the stated diffraction peaks at ~0% RH.

The claim language does not explicitly use terms like “polymorph,” “hydrate,” or “solvate,” but the specificity of XRPD at a defined RH and DSC/TGA signatures functions as the practical surrogate definition.

What formulation scope is covered: drug product, dosage form, or only the solid form?

Answer: The independent claim is a method of treatment defined by the solid form of the active (RAD1901-2HCl). It does not require a specific dosage form (tablet, capsule, powder blend) in the claim text you provided.

What is explicitly required

Solid form identity: XRPD peak positions at ~0% RH
Therapy: breast cancer treatment
No explicit excipient/dosage form requirement appears in the provided claims.

What is not explicitly limited in the claims provided

Particle size
Specific manufacturing method for producing the solid form
Solubility or dissolution rate
Drug product composition

Enforcement implication: challengers can still argue non-infringement if their RAD1901-2HCl solid form does not meet the XRPD signature. But they cannot avoid infringement by changing excipients alone if the same solid form is administered.

What ER+ and endocrine-resistance claims add to the patent’s value?

Answer: Claims 16–21 add clinical targeting and regimen constraints, which can be used to support narrower infringement theories aligned with specific patient populations or combination therapy protocols.

ER+ and resistant ER-driven cancer

Claim 16: ER+ status is required
Claim 17: resistance context after endocrinological treatment

Regimen flexibility in claim 17–18

Claim 17 uses a broad enumerated list that includes multiple classes: SERDs, aromatase inhibitors, SERMs, HER2 inhibitors, chemo, CDK4/6, mTOR, rituximab.

Claim 18 then provides explicit example selections, particularly SERDs (including named agents) and endocrine classes.

Strategic implication: even if a competitor’s intended use is anchored on a specific endocrine-resistant protocol, the patent’s broad “selected drug class” enumeration increases the chance of alignment with the actual clinical practice.

Mutation-based limitation in claim 21

Claim 21 requires ER binding domain mutations from the enumerated set:

Y537X1 (X1 = S/N/C)
D538G
L536X2 (X2 = R/Q)
P535H
V534E
S463P
V392I
E380Q

Strategic implication: this narrows the clinical scope but provides strong defensibility in precision-medicine settings, where genotyping drives patient selection.

How strong is the patent estate for a “solid form identity” strategy under U.S. practice?

Answer: The estate strength is usually higher when the patent ties infringement to objective analytical tests (XRPD/DSC/TGA) that can be measured by an accused product. Here, the claims include multiple independent identity constraints (XRPD plus DSC/TGA dependent options).

Strength drivers in this claim set

Objective, numerical XRPD windows (2θ positions, ±0.2°)
Additional orthogonal analytical signatures (DSC onset and endotherm, plus TGA figure references)
Broad “comprising” peak language
Tight environmental testing condition (about 0% RH) that reduces ambiguity about which solid form variant is claimed

Litigation friction points

The accused solid form must be tested under conditions that support a match to the claimed “about relative humidity 0%”
If the competitor markets a different solid form (different polymorph/solvate/amorphous), non-infringement may be argued even if the drug substance is chemically the same salt.

What generic or biosimilar entry risks exist for RAD1901-2HCl methods?

Answer: The primary generic risk is not chemical equivalence; it is solid form equivalence. Entry risk is high if a generic developer replicates the same RAD1901-2HCl solid form that meets the XRPD/DSC/TGA constraints.

Paragraph IV and ANDA-type scenarios (structural)

If a follow-on applicant files an application referencing the marketed product and uses a solid form that satisfies the claimed XRPD signature, the method claims can still be asserted based on administration of the claimed solid form to ER+ or resistant ER-driven breast cancer patients under the claimed regimens.

Key knock-out defense

A defendant can reduce risk by proving their RAD1901-2HCl solid form does not match required XRPD peaks under ~0% RH.

How does the claim structure support multiple infringement theories?

Answer: The patent offers layered claim theories:

Broad: claim 1 only needs the 7.1° XRPD peak at ~0% RH plus breast cancer treatment
Intermediate: add multiple XRPD peaks (claims 2–12)
Narrow: require DSC and/or TGA profiles (claims 13–15)
Clinical: require ER+ and then resistant/combination regimens (claims 16–21)

Practical effect: in litigation, the patentee can pursue the broadest claims that survive validity and then narrow to dependent claims that match the evidentiary profile of the accused material and the intended/actual patient population.

Key data matrix: claim elements tied to measurable solid-form properties vs clinical treatment properties

Claim element	What it requires	Where it appears	How it is tested/proved
Solid form identity	XRPD peak at 7.1° ±0.2° at ~0% RH	Claim 1	XRPD measurement at specified humidity
Extended XRPD signature	Additional peaks at specified 2θ windows (±0.2°)	Claims 2–12	XRPD pattern matching, peak presence/count
Full peak set lock-in	Enumerated full set of peaks	Claim 11	XRPD comparison across all recited peaks
Figure-based XRPD	“as shown in FIG. 4G” at ~0% RH	Claim 12	Figure-to-data mapping
DSC identity	melting onset 218.2°C; endotherm at 232.1°C	Claim 13	DSC thermogram analysis
DSC figure-based	“as shown in bottom figure of FIG. 8”	Claim 14	Figure-to-data mapping
TGA identity	“as shown in top graph of FIG. 8”	Claim 15	TGA curves matching
Disease	breast cancer; ER+	Claims 1, 16	Clinical indication/usage; patient selection
Resistance context	progressed after endocrinological treatment	Claim 17	Treatment history and regimen
Combination regimens	CDK4/6 and/or mTOR; list of specific agents	Claims 19–20	Labeling/clinical protocol; administration
ER mutation profile	enumerated ER LBD mutations	Claim 21	Genotyping evidence

What patent landscape details can be concluded from the claims provided?

Answer: From the claim text alone, the landscape conclusion is limited to the scope of US 10,745,343 itself: it is an identity-and-method patent that targets a specific RAD1901-2HCl solid form characterized by XRPD at ~0% RH, then layers clinical patient and regimen limitations.

A broader landscape summary (priority dates, assignee, prosecution history, related U.S. family members, continuations/divisionals, and co-pending litigation/settlements) cannot be produced accurately from the claims alone.

Key Takeaways

US 10,745,343’s infringement hinges on a specific RAD1901-2HCl solid form defined by XRPD peak position at ~0% relative humidity, starting with a required 7.1° (2θ ±0.2°) peak.
Dependent claims add a structured ramp from peak-count requirements to a full enumerated XRPD signature plus DSC/TGA identity constraints.
Clinical dependent claims narrow to ER+, endocrine-resistant ER-driven disease post-treatment, and further specify combination regimens and enumerated ER mutations.
For generics or solid-form entrants, the key risk is solid-form non-equivalence. Changing excipients or dosing form alone may not avoid liability if the same XRPD/DSC/TGA-defined solid form is administered.

FAQs

What XRPD peak is required by US 10,745,343 to meet claim 1?
7.1° 2θ ±0.2° at about relative humidity 0%.
Does US 10,745,343 require a specific dosage form (tablet vs capsule)?
The provided claim text defines method and solid-form identity; it does not specify a dosage form.
Which dependent claims add DSC and TGA limitations to the RAD1901-2HCl solid form?
DSC melting/endotherm is in claim 13 (with figure-based claim 14). TGA figure-based limitation is in claim 15.
What ER mutation types are included in claim 21?
Enumerated ER binding domain mutations including Y537X1 (S/N/C), D538G, L536X2 (R/Q), P535H, V534E, S463P, V392I, and E380Q.
How do claims 2–10 differ from claim 11?
Claims 2–10 set minimum counts of peaks from defined sets, while claim 11 requires the full recited peak set at ~0% RH.

References (APA)

US Patent 10,745,343. Claims as provided in prompt.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Stemline Therap	ORSERDU	elacestrant hydrochloride	TABLET;ORAL	217639-001	Jan 27, 2023		RX	Yes	No	⤷ Start Trial	⤷ Start Trial				TREATMENT OF AN ER-POSITIVE BREAST CANCER	⤷ Start Trial
Stemline Therap	ORSERDU	elacestrant hydrochloride	TABLET;ORAL	217639-002	Jan 27, 2023		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial				TREATMENT OF AN ER-POSITIVE BREAST CANCER	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2018205285	⤷ Start Trial
Australia	2023202085	⤷ Start Trial
Australia	2025205244	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,745,343

Which drugs does patent 10,745,343 protect, and when does it expire?

Summary for Patent: 10,745,343