CurrentCentenePolicy CP PMN.84

Timothy Grass Pollen Allergen Extract (Grastek)

Defines medical necessity criteria, approval durations, continuation criteria, exclusions, dosing, contraindications, and product availability for Grastek (Timothy grass pollen sublingual tablet) across Commercial, HIM, and Medicaid lines of business.

Policy Summary

PayerCentene

PolicyTimothy Grass Pollen Allergen Extract (Grastek)

Policy CodePolicy CP PMN.84

Change TypeStep therapy bypass added for IL HIM; prior duration revision; routine annual reviews

Effective Date11.16.16

Next Review Date

Key ActionProvider must submit documentation (office chart notes, lab results or other clinical information) supporting that member has met all approval criteria.

POLICY UPDATE CHANGES

Added step therapy bypass for IL HIM per IL HB 5395 (effective 2026-01-01 referenced in body; logged 3Q 2025 annual review).

Revised approval duration for Commercial line of business to 12 months or duration of request, whichever is less (noted in 2021 revisions).

Multiple annual reviews from 2021-2024 noted 'no significant changes' and references updated.

1Required prior failures (classes)

1Max tablets per day

5-65Age range (years)

12 months

Coverage Summary

Grastek is an FDA‑approved sublingual immunotherapy (Timothy grass pollen allergen extract) indicated for treatment of grass pollen‑induced allergic rhinitis with or without conjunctivitis in persons approximately 5 through 65 years of age. The product is a 2,800 BAU tablet administered once daily per the prescribing information and policy description.

Treatment with Grastek may be continued for up to three consecutive years for sustained effectiveness. This clinical policy (Reference Number: CP PMN.84, status CURRENT) adopts a coverage stance of covered with criteria and defines medical necessity criteria, dosing limits, age eligibility, required testing, prescriber/consultation expectations, step therapy requirements, approval durations, and documentation requirements for Commercial, HIM, and Medicaid lines of business.

Key thresholds

Age eligibility>= 5 years and <= 65 years (policy text also contains '5 through 65' and '5 and <65')

Maximum daily dose1 tablet/day

Typical approval duration (Medicaid/HIM)12 months

Typical approval duration (Commercial)12 months or duration of request, whichever is less

Product strength and dosingTablet contains 2,800 BAU and is dosed once daily; may be used up to three consecutive years for sustained effectiveness

Initial Therapy Criteria

Step Therapy

Step therapy required (with IL HIM exception)

Generally requires failure of one intranasal corticosteroid and one oral antihistamine before approval unless clinically significant adverse effects are experienced or all are contraindicated. For Illinois HIM requests, the step therapy requirements do not apply as of 2026-01-01 per IL HB 5395.

IL HIM: step therapy bypass per IL HB 5395 (effective 2026-01-01)

Prior Authorization

Prior authorization required

Prior authorization is required; requests must meet the policy's initial or continued therapy criteria and applicable approval durations.

Initial Approval Duration

Denial Risk

Dose limit enforcement

Requests for doses exceeding 1 tablet per day will not meet the policy dose criteria and may be denied.

Continuation Therapy Criteria

Documentation Required

Supporting documentation required

Provider must submit supporting documentation such as office chart notes, lab results, or other clinical information showing the member has met all approval criteria.

Unproven / Exclusions

Diagnoses/Indications Not Covered

Non-FDA approved indications not addressed in this policy are not authorized unless there is sufficient documentation of efficacy and safety according to the off-label use policies (e.g., CP.CPA.09 for commercial, HIM.PA.154 for health insurance marketplace, CP.PMN.53 for Medicaid) or evidence of coverage documents.

Requests for non‑FDA (off‑label) indications are not authorized by this policy unless sufficient documentation of efficacy and safety is provided in accordance with the referenced off‑label use policies (CP.CPA.09 for Commercial, HIM.PA.154 for Health Insurance Marketplace, and CP.PMN.53 for Medicaid). This policy is also explicit that Grastek is not indicated for immediate symptom relief and should not be used for that purpose.

Applicable Codes

N/A - No procedure or HCPCS/CPT codes specifiedmixed

No codes listed

Provider Actions & Billing Impacts

Prior Authorization

Prior authorization and criteria

Requests must meet the policy's initial or continued therapy criteria and the listed approval durations; prior authorization is implied by the requirement to submit documentation and apply the policy criteria.

Documentation Required

Continuity of care

Continuity of care and state/product continuity provisions apply where relevant; refer to state-specific addendums for applicable continuity rules.

Clinical Evidence & References

Key evidence sources include the Grastek Prescribing Information (Merck; December 2019; accessed April 18, 2025) and multiple guideline/practice parameter references such as Wallace et al., Seidman et al., ARIA, and focused updates on sublingual immunotherapy.

Clinical evidence and guideline context support that sublingual immunotherapy with grass pollen extracts (including Grastek) can be effective for grass pollen‑induced allergic rhinitis and that treatment courses of up to three years are recommended to achieve sustained effectiveness.

Background & Definitions

Grastek is not intended for immediate symptom relief and should be initiated and used according to dosing guidance: one 2,800 BAU tablet taken once daily, with consideration of starting at least 12 weeks before expected pollen season; age eligibility is generally stated as 5 through 65 years in the FDA label and the policy uses age criteria consistent with this range.

Definitions

BAUbioequivalent allergy unit

Revision History

04.21.25materialLatest

3Q 2025 annual review: added step therapy bypass for IL HIM per IL HB 5395 (effective 2026-01-01); P&T Approval Date = 08.25.

09.28.21revised

Revised approval duration for Commercial line of business to 12 months or duration of request, whichever is less; logged Date = 09.28.21; P&T Approval Date = 02.22.

03.22.21annual_review

3Q 2021 annual review: no significant changes; references updated (HIMPHAR.21 revised to HIMPA.154); Date = 03.22.21; P&T Approval Date = 08.21.