EMA Hybrid Applications Under Article 10(3): Data Requirements and Bridging Study Precedent

EMA hybrid applications under Article 10(3): data requirements and when bridging studies are needed

Hybrid marketing authorisation applications (MAAs) under Article 10(3) of Directive 2001/83/EC sit between a pure generic and a full stand-alone dossier. The applicant relies on the reference medicinal product's pre-clinical and clinical results, and adds new data to bridge whatever separates its product from that reference. This article sets out what the legislation requires and how CHMP has applied it in practice, drawing on European Public Assessment Reports (EPARs) for authorised, refused and withdrawn hybrids.

The legal basis

When Article 10(3) applies

Article 10(3) states: "In cases where the medicinal product does not fall within the definition of a generic medicinal product as provided in paragraph 2(b) or where the bioequivalence cannot be demonstrated through bioavailability studies or in case of changes in the active substance(s), therapeutic indications, strength, pharmaceutical form or route of administration, vis-à-vis the reference medicinal product, the results of the appropriate pre-clinical tests or clinical trials shall be provided." ⁷⁶

Any one of these grounds is sufficient to trigger the hybrid route. The obligation is to supply the results of the appropriate pre-clinical tests or clinical trials; Article 10(3) is not an automatic exemption from new data ⁷⁶.

The comparison point is the generic definition in Article 10(2)(b): the same qualitative and quantitative composition in active substances and the same pharmaceutical form as the reference product, with bioequivalence demonstrated by appropriate bioavailability studies ⁷⁵. A hybrid is, in effect, a product that departs from one or more elements of that definition.

Data protection periods

Because hybrids rely on the reference dossier, the Article 10(1) periods apply; centrally authorised hybrids are subject to the same 8+2+1 periods under Article 14(11) of Regulation (EC) No 726/2004. The reference product must have been authorised for at least eight years before the application can rely on it, and the product cannot be marketed until ten years after the reference product's initial authorisation. That period extends to a maximum of eleven years if the reference product's holder obtained, within the first eight years, a new indication offering significant clinical benefit over existing therapies ⁷³⁷⁴.

Annex I, Part II

Annex I Part II ("Specific applications") gives the technical content. Generic applications contain Modules 1, 2 and 3 of Part I together with bioavailability and bioequivalence data against the original product ³⁶, and the non-clinical and clinical overviews must evaluate the bioequivalence studies or justify why studies were not performed ³⁸. Under "Additional data required in specific situations", Annex I states that where a product "is intended for a different therapeutic use or presented in a different pharmaceutical form or to be administered by different routes or in different doses or with a different posology, the results of appropriate toxicological and pharmacological tests and/or of clinical trials shall be provided" ³⁵. For a different salt, ester, ether, isomer, mixture of isomers, complex or derivative of the same therapeutic moiety, the applicant must show no change in pharmacokinetics, pharmacodynamics or toxicity that could alter safety or efficacy; otherwise the substance is treated as a new active substance ³⁴.

In practice, the hybrid dossier therefore consists of a full quality module plus a non-clinical and clinical package that relies on the reference product and adds the bridging evidence needed for the specific difference.

What EMA guidance adds

The bioequivalence guideline applies to hybrids. The Guideline on the investigation of bioequivalence (Rev. 1) states under its legal basis that it may also apply to Article 10(3) hybrid applications ¹²⁸. The test product in a generic or hybrid application is normally compared with the corresponding dosage form of the reference product, where one is marketed ⁶¹⁶². The draft revision describes hybrid applications as relying on the reference product's pre-clinical and clinical results while including new data, which may be bioequivalence or comparative bioavailability data ⁶³.

Pharmacodynamic or clinical endpoints are exceptional, not default. Where bioequivalence cannot be shown using drug concentrations, pharmacodynamic or clinical endpoints "may be needed in exceptional circumstances," with therapeutic-area guidelines governing the details ¹²⁷. For locally applied, locally acting products, the bioequivalence guideline points to product-specific guidance and requires that any systemic exposure posing a safety risk be measured and shown not to exceed the reference ¹²⁴.

Locally acting products follow a stepwise approach. For orally inhaled products, equivalence may be shown in vitro if all in vitro criteria are met; otherwise PK studies demonstrating equivalent systemic exposure (safety surrogate) and equivalent lung deposition (efficacy surrogate) are the preferred next step ⁹⁸. For cutaneous products, the sequence runs from pharmaceutical equivalence (Q1/Q2/Q3 and in vitro release) to permeation kinetics, then to PD or clinical endpoints if earlier steps fail; narrow-therapeutic-index products in principle require clinical endpoint studies ^99101102103. For locally acting gastrointestinal products, clinical endpoint trials are necessary in principle, although justified alternatives such as quality data plus in vitro models or PK may be used ¹⁰⁰.

Modified-release reformulations of IR products need more than BE. The modified-release guideline treats a new MR formulation of a drug authorised in a different release form (its Section 5) separately from an abridged MR application referencing a marketed MR product (Section 6), and notes that Section 6 can include Article 10(3) applications ²³. For the IR-to-MR scenario, clinical efficacy and safety studies are not merely an exception; a waiver is possible if one of three conditions is met ²⁴. Where therapeutic studies are needed, MR and IR can be compared at equal exposure using equivalence or non-inferiority designs, and a different claimed indication requires a clinical development plan ³²⁵.

When CHMP has required bridging studies: patterns from EPARs

The EPARs show that the bridging package scales with the size of the gap between the hybrid and its reference. The table summarises representative cases; the sections that follow draw out the decision logic.

Pharmaceutical form changes with the same route: BE is the default bridge

For oral reformulations (solutions, suspensions, orodispersible tablets, new tablet strengths), CHMP has generally expected an in vivo BE study against the EU reference. Thalidomide Lipomed (100 mg coated tablet versus 50 mg capsule) was supported by a bioequivalence study and published data ²³¹²³³. Bopediat (5 mg furosemide orodispersible tablet versus 20 mg tablets) was supported by an in vivo BE study, while the proposed biowaiver for a 1 mg strength was not accepted and that strength was withdrawn ^310311312.

Strict bioequivalence is not always a precondition for approval of a hybrid. In Jayempi, CHMP considered the BE design appropriate but the study failed its Cmax limit; because strict BE is not required for a different-formulation hybrid, CHMP accepted literature showing the higher peak exposure had no clinically relevant consequence ⁴⁸⁸⁴⁵⁴. Alkindi was accepted as therapeutically equivalent on the strength of AUC bioequivalence and supportive clinical data despite uncertainty on Cmax ³⁰⁶³⁰⁵.

Where the reference product's form makes direct comparison impossible, applicants have bridged through another presentation within the reference product's global marketing authorisation. For Jylamvo (methotrexate 2 mg/mL oral solution), direct BE against the injectable reference was not feasible, so BE studies against originator tablets bridged to the originator's clinical data ³³¹³³².

Dose strength and PK linearity drive study selection. CHMP requested a highest-strength study for Nimvastid because rivastigmine has nonlinear pharmacokinetics ³⁶⁸. For Paxneury, non-proportional formulations across the low and high strength ranges required separate single-dose fasted/fed and multiple-dose assessments, and without the 7 mg study the hybrid strengths lacked robust clinical data ³⁰⁰.

Release-rate and route changes: exposure matching, sometimes efficacy data

When the hybrid changes release rate or route, CHMP has moved away from strict BE toward exposure-based or clinical bridges. For Okedi, an intramuscular risperidone depot referencing oral Risperdal tablets, CHMP considered an in vivo PK bridge against the EU reference pivotal to relying on the reference product's non-clinical, interaction, efficacy and safety data; similar total active-moiety exposure was required, but strict bioequivalence was not ³⁸¹.

For Tuzulby, an extended-release chewable methylphenidate referencing Ritalin IR tablets, the plasma concentration-time profiles differ ³⁴⁶. CHMP did not consider plasma levels and indirect efficacy arguments sufficient to waive comparative efficacy and safety evidence, but accepted the total package, which included a placebo-controlled efficacy and safety study ³⁴⁷³⁴⁸.

Midazolam products illustrate the route-change pattern. Buccolam (oromucosal solution, new route and seizure indication versus injectable Hypnovel) relied on a paediatric population-PK study, simulations and published efficacy literature ²⁸¹²⁷⁴. For Tuzodi and Omforro (intranasal midazolam versus intravenous Hypnovel), the different forms precluded a comparative BE study, and the applicants relied on comparative PK/PD study MDZ-NS-22 plus modelling; assessors raised concerns about exposure differences and paediatric PK extrapolation, and both applications were withdrawn ^276272395.

New indications: the applicant's own clinical data carry the benefit

Where the hybrid adds or changes an indication, the reference product's efficacy data are of limited relevance and CHMP has expected the applicant's own clinical evidence. Examples include:

• Hyftor (topical sirolimus for facial angiofibroma): Rapamune efficacy data were not relevant to the new indication, and with much lower systemic exposure and a comprehensive own clinical programme, the comparative bioavailability study was not pivotal ³⁵⁰.
• Zalviso (sublingual sufentanil for postoperative pain versus intravenous/epidural Sufenta): CHMP agreed that comparative bioavailability and reference-product studies were unnecessary because reliance on Sufenta was limited, notably to non-clinical data, while new clinical data supported the different route and indication ²⁸⁰.
• Kinpeygo (budesonide for IgA nephropathy, referencing Entocort): the applicant's own clinical data supported the new indication ²²⁹, with the pivotal phase 3 study Nef-301 Part B required to verify clinical benefit ²⁸³.
• Ryjunea (low-dose atropine eye drops for myopia): CHMP accepted the absence of a comparative clinical or bioavailability study because the application referred to reference data only in limited areas ⁴⁹⁷.
• Colchicine AGEPHA Pharma (new cardiovascular indication): dissolution similarity and BE studies against Colgout bridged the proposed tablet to the formulations used in published LoDoCo/LoDoCo2 trials ⁴⁰⁹⁴¹⁰.

Literature can substitute for new studies where the evidence base is strong. Methylthioninium chloride Proveblue, with a changed strength and extended indication, used bibliographic data in place of all non-clinical tests and clinical studies ²¹⁹²²⁰.

Locally acting inhaled products: PK, PD and safety bridges in place of phase 3

The budesonide/formoterol Spiromax hybrids referencing Symbicort Turbuhaler were developed on PK equivalence at each strength, plus one PD study and one safety study, with no comparative phase 3 efficacy or safety studies, following the CHMP orally inhaled products guideline ^160170175. For Aerivio Spiromax (salmeterol/fluticasone versus Seretide Accuhaler), CHMP accepted the absence of new PD and clinical studies because PK equivalence had been demonstrated ¹⁸⁶.

Vantobra (tobramycin nebuliser solution versus TOBI) did not meet strict protocol-defined bioequivalence. CHMP nevertheless considered the comparative PK data, in both cystic fibrosis patients and healthy volunteers, an adequate bridge because the in vivo differences were small and unlikely to affect efficacy or safety ¹⁹²¹⁹³.

Parenteral solutions: in vitro comparability can replace BE, within limits

For intravenous products, CHMP has accepted BE waivers where formulation comparability is convincingly shown. Topotecan Teva (ready-to-use concentrate versus Hycamtin powder) required no further data because the infused concentration and regimens were the same ³⁴². Docefrez received a waiver after physicochemical and micelle comparisons confirmed pharmaceutical comparability with Taxotere ²⁸². Phelinun's waiver was accepted in principle because the melphalan concentration, administration method and excipients were comparable ³⁸⁸. For Hydrocortisone Aguettant, CHMP considered PK bridging unnecessary given intravenous administration and in vitro comparability ⁴⁰³⁴⁰⁴.

The waiver fails when excipients could change disposition. For Docetaxel Mylan, which replaced polysorbate with polyethylene glycol stearate, CHMP identified the absence of comparative PK/PD evidence on the final formulation as a major deficiency, and required toxicity evidence because the new surfactant could affect toxicity and PK ³³⁹. The application was withdrawn ³³⁶.

Complex products: analytical and PD bridges

For Liraglutide STADA (synthetic versus biologically derived liraglutide referencing Victoza), CHMP noted that bioequivalence alone might not suffice given molecular complexity. Analytical comparability of properties relevant to PK, PD and immunogenicity justified waiving clinical PD, efficacy and immunogenicity studies ^446447448. For Camcevi, CHMP accepted a PD bridge based on testosterone suppression, with in vitro release only supportive because of the complex depot formulations ³⁹⁰³⁹⁴.

Common reasons hybrid applications fail

Several EPARs show recurring deficiencies:

• Non-EU comparator. For Asimtufii (aripiprazole prolonged-release injection), CHMP considered the clinical overview sufficient for PD, efficacy and safety but rejected the pivotal multiple-dose bioavailability study because it used a non-EU/EEA comparator; an Article 10(3) bridge must use the EU/EEA reference ¹⁹⁶²²⁴. CHMP also questioned whether the Omforro comparator was the Union-authorised reference ³⁹⁵.
• Wrong reference product or active substance. Cabazitaxel Teva cited Taxotere (docetaxel) as reference while relying on Jevtana data. CHMP considered the IV biowaiver adequately substantiated but rejected reliance on Taxotere because cabazitaxel and docetaxel had not been shown to be the same active substance for this purpose, and the application was refused ⁴⁵²³²⁴.
• Formulation not performing as claimed. For Sildenafil FGK (oral lyophilisate), the PK study did not substantiate the claimed sublingual formulation because the product did not consistently dissolve under the tongue ²⁵⁰²⁵¹.
• Unsupported excipient changes. As with Docetaxel Mylan, a BE waiver requires demonstrated quality and non-clinical comparability ³³⁹.

Practical takeaways

1. Identify every element of departure from Article 10(2)(b) (composition, form, strength, route, indication, release rate) because each one determines what "appropriate" data means under Article 10(3) ⁷⁶³⁵.
2. Use an EU/EEA-sourced reference product for pivotal bridging studies ¹⁹⁶²²⁴.
3. Same-route oral reformulations are typically bridged by BE studies under the bioequivalence guideline, which expressly may apply to hybrids ¹²⁸. Strict BE failure is not automatically fatal if the clinical consequence of an exposure difference is justified ⁴⁸⁸³⁰⁶.
4. Release-rate and route changes usually require exposure matching and may require clinical efficacy data when PK profiles differ in shape ³⁸¹³⁴⁸.
5. New indications require the applicant's own clinical evidence; reliance on the reference product narrows to non-clinical and general safety data ^350280497.
6. Locally acting products follow the product-specific stepwise guidance, with PK, PD and safety studies often replacing phase 3 for inhaled products ⁹⁸¹⁶⁰.
7. For IV products, in vitro and physicochemical comparability can support a BE waiver, but any excipient change that could affect disposition or toxicity needs non-clinical or clinical support ²⁸²³³⁹.

The appropriate bridging package for a specific hybrid depends on the reference product, the therapeutic area guideline and the nature of the change. Product-specific questions, such as how CHMP handled a particular form or route change in a given class, are best explored by examining the relevant EPARs in detail.