United States Patent 6,960,577: Scope, Claims, and US Patent Landscape for Olanzapine + Fluoxetine in Treatment-Resistant Major Depression

What does US 6,960,577 protect?

US 6,960,577 protects method-of-treatment claims for treating treatment-resistant major depression by administering a combination of:

First component: olanzapine (or pharmaceutically acceptable salts)
Second component: fluoxetine (or pharmaceutically acceptable salts)

The patent’s practical scope is therefore constrained to combination therapy (not monotherapy), olanzapine plus fluoxetine, and a specific indication (treatment-resistant major depression).

Claim set (as provided)

Claim 1: Treating a patient with or susceptible to treatment-resistant major depression by administering:
- an effective amount of olanzapine (or salt) in combination with
- an effective amount of fluoxetine (or salt)
Claim 2: Method of claim 1 where administration is oral
Claim 3: Treating treatment-resistant major depression by administering:
- olanzapine in combination with
- fluoxetine
Claim 4: Treating treatment-resistant major depression by administering:
- olanzapine in combination with
- fluoxetine hydrochloride

Structural implication: Claims 1 and 2 are framed broadly around component identity + indication, while claims 3 and 4 narrow the salt/chemical specificity (claim 4 explicitly to fluoxetine hydrochloride) and remove the explicit “salt” language for the second component in claim 3.

What is the claim scope in operational terms?

1) Indication scope: “treatment-resistant major depression”

The claims require that the patient is:

suffering from, or
susceptible to, treatment-resistant major depression.

That phrasing typically covers both established treatment resistance and patients expected to develop resistance based on clinical criteria. The claims do not recite a threshold definition (for example, number of prior failures or specific prior drug classes), which makes the claim scope dependent on how “treatment-resistant” is interpreted during enforcement and litigation.

2) Drug scope: olanzapine + fluoxetine (combination only)

The claims require both components:

olanzapine (or acceptable salts)
fluoxetine (or acceptable salts)

This excludes:

olanzapine without fluoxetine,
fluoxetine without olanzapine,
other antidepressants substituted for fluoxetine,
other antipsychotics substituted for olanzapine.

3) Salt and formulation scope

Claim 1 and claim 3: fluoxetine can be a salt (claim 1) or specifically “fluoxetine” (claim 3).
Claim 4: fluoxetine is specified as fluoxetine hydrochloride.

In enforcement, a key distinction is that claim 4 provides a fallback to a specific salt form. If a competitor used fluoxetine in another salt or salt-free form, claim 4 may not apply as cleanly, but claim 1 likely still captures “pharmaceutically acceptable salt(s).”

4) Route scope: oral administration

Claim 2 adds that administration is oral. That creates a narrower subset within claim 1. In practice, if a product is oral, it can fall under claim 2. If a competitor attempted non-oral delivery (if such a regimen exists for that combination), claim 2 would not be directly met while claim 1 could still be argued (depending on how “comprising administering” is interpreted vis-à-vis oral limitation and the presence/absence of route limitations elsewhere in the claim set).

5) Dose and schedule scope

The claims specify “an effective amount” for each component but do not specify:

dose levels,
titration schedules,
timing (simultaneous vs sequential),
duration.

This typically yields broad protection across dosing regimens that achieve therapeutic effect.

How broad is the claim coverage vs typical US practice?

Compared with patents that claim:

a particular dosing regimen,
a specific fixed-dose ratio,
a particular titration schedule, US 6,960,577 is indication- and component-driven. The result is broader coverage against any oral (per claim 2) or otherwise administered regimen that uses the same two drugs for treatment-resistant major depression.

What is the relevant competitor threat profile?

Direct design-around barriers

To avoid the core combination claims (1, 3, 4), a competitor would need to avoid at least one of:

olanzapine (replace it with a different antipsychotic), or
fluoxetine (replace it with a different SSRI or other antidepressant), or
the indication framing (avoid treatment-resistant major depression as the claimed target population).

Partial relief paths (not full avoidance)

Using a different fluoxetine salt form: claim 1 still reads on “fluoxetine (or pharmaceutically acceptable salt thereof).”
Using non-oral route: claim 2 would not apply, but claim 1 may still apply if no other route constraint exists in the asserted claim.

How does this patent fit into the US olanzapine plus fluoxetine landscape?

Even without relying on additional text from the specification, the claim structure aligns with the known market reality that olanzapine + fluoxetine is the backbone of a branded combination for depressive disorders and has attracted follow-on protection strategies.

Practical landscape dimensions to evaluate for US enforcement and freedom-to-operate

Compound patent coverage: patents protecting olanzapine, fluoxetine, or their combinations historically.
Method-of-use coverage: patents like US 6,960,577 that lock down a specific clinical population and dosing combination concept.
Formulation patents: fixed-dose combinations, specific tablets/capsules, or polymorph/processing patents (these can matter for product design even when method claims exist).
Regulatory exclusivities and Orange Book entries: determines whether ANDA applicants are required to certify around specific patents.
Other method patents on related depressive phenotypes: treatment-resistant vs other refractory or partial-response labels can create overlapping or competing protection.

Business implication: A competitor can often reach the market with a generic product that is chemically the same but still face exposure if they market/use it for a protected indication.

What is the likely claim construction center of gravity in litigation?

Given the claims as written, the most litigated elements tend to be:

whether the accused regimen uses olanzapine + fluoxetine as required,
how “treatment-resistant major depression” is proven in the real world (documentation, prescriber intent, labeling, patient selection),
whether the method involves oral administration (for claim 2 only),
whether the accused fluoxetine form qualifies under “fluoxetine” or “pharmaceutically acceptable salt(s)” (for claims 1 and 4).

How to map US 6,960,577 to freedom-to-operate decisions

For a generic or biosimilar-like combination entrant

If the entrant’s product is olanzapine + fluoxetine, the chemical barrier is low for novelty but the indication can create method claim risk.
If the marketing and clinical use includes treatment-resistant major depression, the risk aligns closely with claims 1, 3, and potentially claim 4 depending on salt form.

For a branded entrant expanding indications

If a company expands into other depressive disorders (non-treatment-resistant), it can preserve differentiation from this method claim set.
But any protocol that targets treatment-resistant major depression could trigger exposure if the regimen is within the olanzapine + fluoxetine combination.

What other US patents typically cluster with this kind of claim?

In this combination space, closely related filings often include:

other method-of-use patents for depressive disorder subgroups (for example, treatment-resistant vs relapse prevention),
combination dosing patents (specific dosing ratios or titration schedules),
fixed-dose combination product patents (tablet/capsule composition, processing).

However, producing a complete and accurate “US patent landscape” map for 6,960,577 requires the actual publication/bibliographic records, assignee, filing date, prosecution history, and citation set, which are not provided here. The claim scope analysis above therefore anchors the landscape only to what can be derived from the claim language supplied.

Key scope table

Claim	Patient population requirement	First component	Second component	Route limitation	Breadth notes
1	Treatment-resistant major depression (suffering or susceptible)	Olanzapine or pharmaceutically acceptable salt	Fluoxetine or pharmaceutically acceptable salt	None stated	Broadest because it covers salts for both components
2	Same as claim 1	Olanzapine or salt	Fluoxetine or salt	Oral	Subset of claim 1 limited to oral administration
3	Same as claim 1	Olanzapine (no explicit “salt” language in provided text)	Fluoxetine	None stated	Narrows salt language for olanzapine vs claim 1 as presented
4	Same as claim 1	Olanzapine	Fluoxetine hydrochloride	None stated	Provides a salt-specific fallback for second component

Key Takeaways

US 6,960,577 is a method-of-treatment patent that requires combination therapy of olanzapine + fluoxetine for treatment-resistant major depression.
The strongest coverage is claim 1: it captures both fluoxetine and salt forms and does not restrict route.
Claim 2 is the route-narrowed subset limited to oral administration.
Claim 4 adds fluoxetine hydrochloride specificity as a narrower fallback.
Design-around efforts must break at least one hard element: replace olanzapine, replace fluoxetine, or avoid the treatment-resistant major depression use case.

FAQs

Does US 6,960,577 cover olanzapine plus fluoxetine for non–treatment-resistant depression?
No. The claims require “treatment-resistant major depression” (suffering or susceptible).
Can a competitor escape claim 4 by using a different fluoxetine salt form?
Claim 4 is specific to fluoxetine hydrochloride, but claim 1 still covers fluoxetine (or pharmaceutically acceptable salt thereof).
Is oral dosing required for the broadest claim?
No. Claim 1 has no oral limitation as presented. Claim 2 adds “oral.”
Do the claims require a fixed dose ratio or specific milligram amounts?
No. Each component is “an effective amount,” with no dose ratio or schedule specified in the claim text provided.
If a product contains both drugs, does that automatically infringe?
Method claims require use to treat treatment-resistant major depression. The combination’s presence alone does not complete every claim element without the required patient population context.

References

[1] United States Patent US 6,960,577, “Method for treating treatment resistant major depression using olanzapine and fluoxetine,” claims as provided by user.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	4008699	⤷ Start Trial
Australia	761510	⤷ Start Trial
Brazil	9911049	⤷ Start Trial
Canada	2332814	⤷ Start Trial
China	1154496	⤷ Start Trial
China	1311681	⤷ Start Trial
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Details for Patent: 6,960,577

Summary for Patent: 6,960,577