GnRH agonists and antagonists in prostate cancer

Author byline as per print journal: Robert Janknegt, PharmD, PhD, Niels Boone, PharmD, Frans Erdkamp, MD, PhD, Victor Zambon, MD

Abstract:
This manuscript describes the System of Objectified Judgement Analysis (SOJA) method applied to gonadotropin-releasing hormone (GnRH) agonists and antagonists in prostate cancer. The following selection criteria were used: efficacy, safety, tolerability, dosage frequency, user-friendly formulation, drug interactions, precaution and documentation. The GnRH agonists goserelin and leuprorelin show the highest scores, mainly based on more extensive documentation compared with the agonists buserelin and triptorelin. The antagonists abarelix and degarelix show low scores, based on a higher incidence of adverse events, a higher dosage frequency, more drug interactions and a more limited documentation compared with the agonists. The availability of a generic formulation of leuprorelin may lead to a reduction in cost.

Submitted: 10 April 2014; Revised: 29 July 2014; Accepted: 11 August 2014; Published online first: 25 August 2014

Introduction

Prostate cancer
Prostate carcinoma is, after lung carcinoma, the most frequent form of cancer in men [1]. About 8,000 new patients are diagnosed with prostate cancer in The Netherlands each year [2]. The diagnosis of localized prostate cancer has increased considerably, probably because of the measurement of prostate specific antigen (PSA), which is useful in the detection of early stage prostate cancer [1]. A detailed description of the treatment of all stages of prostate cancer falls outside the scope of this manuscript. The reader is referred to the Dutch national guideline for a full overview of the treatment of prostate cancer [1].

Androgens stimulate the growth of both normal and cancerous prostate cells. Androgen deprivation therapy (ADT) is the primary treatment for patients with advanced prostate cancer [2]. Gonadotropin-releasing hormone (GnRH), also known as luteinising hormone release hormone (LHRH) is secreted by the hypothalamus and stimulates the hypophysis to secrete LH, follicle stimulating hormone (FSH) and adrenocorticotropic hormone (ACTH). LH activates the testes to produce testosterone. Chronic administration of GnRH agonists (analogues) blocks the secretion of LH, FSH and ACTH by the hypophysis. This results in a reduction of circulating testosterone levels. GnRH agonists increase survival as effectively as bilateral orchiectomy or treatment with oestrogens [2].

Androgen deprivation therapy (ADT) is a palliative and not a curative treatment of advanced or metastatic prostate cancer. It can normalize serum levels of PSA and can produce objective tumour responses. This antitumour activity can improve quality of life in patients with metastatic prostate cancer by reducing bone pain as well as the rates of complications, such as pathologic fracture, spinal cord compression, and ureteral obstruction. The duration of response to ADT for patients with metastatic disease is highly variable, and most prostate cancer patients eventually experience disease progression despite treatment. Patients who have progressed while on ADT are said to have castration-resistant disease [2].

Applications of GnRH agonists and GnRH antagonists

Patients with high-risk or locally advanced prostate cancer should be treated with external beam radiotherapy plus hormone treatment for at least two years.

Neoadjuvant GnRH agonists are recommended for four to six months in patients receiving radical radiotherapy for high-risk disease and should be considered in patients with intermediate-risk disease. Adjuvant hormonal therapy for two to three years is recommended for men receiving neo-adjuvant hormonal therapy and radical radiotherapy who are at high risk of prostate cancer mortality [1]. The drugs are indicated in the treatment of advanced or metastatic prostate cancer. GnRH agonists are the drugs of choice in metastatic prostate cancer, although a recent guideline from the European Society of Medical Oncology (ESMO) stated that antagonists could be an alternative [1]. Combined androgen depletion (GnRH agonists + ochiectomy) does not offer advantages over chemical or surgical castration only [1].

Guidelines for the treatment of prostate cancer do not specify a medicine of choice within the drug classes. There are no published tools available that could aid therapy choice. In this article the SOJA method was applied to both GnRH agonists and antagonists in order to make a transparent and rational selection of the most suitable medicines.

Methods

The SOJA method is a model for rational drug selection for formulary purposes [3]. See [2] for a detailed description of the methodology. The outcome of this study should be seen as the basis for discussions within formulary committees and not as the absolute truth. The present score is specific for the European situation.

The selection criteria and the relative weights that are assigned by the authors are shown in Table 1. For drugs included in this analysis, see Table 2.

Results

Efficacy
Improved overall survival should be the aim or all cancer treatment but this requires very large scale and long-term studies to establish. Also, both relapse-free survival and disease-free survival are used alternative endpoints in the judgement of clinical efficacy. Relapse-free survival is probably a more relevant endpoint than disease-free survival, because death unrelated to prostate cancer or its complications is included in the latter endpoint.

Outcomes that have been used in trials to establish the role of hormonal therapy in men with advanced prostate cancer include overall survival, measurable tumour response, changes in serum PSA, skeletal-related events, and quality of life (QoL). Complicating the interpretation of results, many studies were conducted prior to the routine use of serum PSA testing in screening and monitoring of disease and therefore these studies do not reflect typical contemporary patient populations or current practice patterns [4].

The prolonged natural history of advanced prostate cancer, its occurrence in older men who often have substantial comorbidity, and the heterogeneity of disease between patients complicate the use of overall survival as an endpoint in assessing response to treatment. The standard classifications of complete response, partial response, stable disease, and progressive disease are inadequate to evaluate response in most men with metastatic prostate cancer. Measurable disease is present in a small fraction of patients. Bone metastases are the most common site of disease, and bone involvement is difficult to measure objectively. Bone scan interpretation is variable, and there is a long healing time when lesions do respond to treatment [4].

PSA levels as a measure of efficacy
The appropriate use of serum PSA as a response endpoint for hormone therapy has not been well studied. The rate of PSA decline following initial hormone therapy relative to the rate of rise prior to initiation of hormone therapy is highly predictive of the time to prostate cancer-specific death [4]. The median survival of those with low PSA levels (< 0.2 ng/mL) was much longer than those with PSA levels of above 4 ng/mL [4].

Inclusion and exclusion criteria
In most cases, we have only used double-blind randomized studies to judge clinical efficacy of drugs included in SOJA analyses. The SOJA model is an instrument that enables users of the programme to determine, on the basis of agreed criteria, an order of merit for the various medicines available in a specific category [3]. This was not done in this SOJA score, because very few double-blind studies have been performed. For this reason, open, randomized phase III studies were included in the analysis. Non-randomized studies and studies comparing GnRH agonists with the addition of a drug such as flutamide or placebo were not included in the analysis, as these studies investigated the effects of the drug added to the GnRH agonist. Studies including a minimum of 25 patients per treatment arm were included in the analysis. Studies with short acting GnRH agonist formulations or nasal formulations were excluded. Similarly, studies in which hormonal treatment was not distinguished from orchiectomy in the same treatment arm were excluded, as well as studies that did not specify the GnRH agonist by name [5].

Direct comparative studies
Few direct comparative studies between GnRH (ant)agonists were identified. One retrospective study was excluded [6] as well as two other studies with a very small number of patients [7, 8] and one non-comparative study [9].

Abarelix versus leuprorelin
One study compared abarelix to leuprorelin. As could be expected testosterone surge was not seen in the abarelix group and did occur in the leuprorelin group [10].

Degarelix versus goserelin
Two studies compared degarelix and goserelin. Testosterone levels decreased more rapidly in the degarelix arm than in the goserelin arm, at eight weeks the levels were similar [11]. The effects of prostate volume and PSA levels were similar at 12 weeks [12]. At the same time point, more patients reported a > 3 point decrease in the International Prostate Symptom Score on degarelix than on goserelin: 36% vs 27% [12].

Degarelix versus leuprorelin
One study compared leuprorelin with degarelix 240 mg (n = 201). The testosterone response rates were comparable at one year. PSA levels declined more quickly in the degarelix group. The final reductions at 364 days were similar in the treatment groups [1315].

Goserelin versus leuprorelin
A double-blind study compared goserelin 3.6 mg every 28 days (n = 540) and leuprorlin (n = 273) in patients with stage D2 (metastatic) prostate cancer. Both drugs were given in combination with either bicalutamide or (50 mg once daily) or flutamide 250 mg tid. The median follow-up was 160 weeks. The effects on time to progression and survival were similar [16].

Leuprorelin versus triptorelin
Two studies compared leuprorelin and triptorelin in patients with advanced prostate cancer. The effects on testosterone were identical. LH and PSA levels fell to a similar extent in both medicines [17, 18].

Studies with individual drugs
Buserelin
In one study buserelin depot was compared to polyestradiol phosphate (PEP). A more favourable effect of buserelin on disease progression was observed after three years of treatment [19]. This study is difficult to interpret because the comparator is not approved in The Netherlands.

Goserelin
Localized prostate cancer

Many studies were performed with goserelin. The medicine was studied as add-on to radiotherapy [2044], showing lower PSA failure [28, 32, 34], increased five years disease-free survival [21, 31, 33, 36, 40] and 10 years [32] and lower degrees of local progression [23, 26, 33], better progression-free survival [26] and lower disease specific mortality at 10 years [23, 28, 33]. There was no effect on overall survival in the majority of the studies. Only one study showed an effect on overall survival at five and 10 years [37, 38].

Advanced prostate cancer

Six studies compared the monthly 3.6 mg and the 10.8 mg dose given every three months of goserelin in patients with advanced prostate cancer. The effects on testosterone levels were similar in the studies [4550].

Other studies compared goserelin (3.6 mg monthly) to various medicines, such as polyestradiol phosphate (PEP) [51], diethylstilbestrol [5254], bicalutamide [5557] and orchiectomy [5861]. Another study compared intermittent and continuous ADT [62].

Goserelin resulted in a longer time to progression [51], objective response rate [52, 53, 58] or no differences in clinically relevant endpoints [5457, 5962].

Metastatic prostate cancer
Several studies compared ADT with goserelin with or without flutamide with surgical orchiecomy in patients with metastatic prostate cancer [6369], resulting in similar effects on objective response rates, time to disease progression and overall survival.

The EORTC 30853 study compared orchiectomy [n = 161] with a combination of goserelin (3.6 mg monthly) plus flutamide (250 mg tid orally, n = 163) in patients with metastatic prostate cancer. Significantly more favourable effects on objective progression and death from cancer were seen in the ADT group [7074]. The time from objective progression to death was however longer in the orchiectomy group [72]. At longer follow-up (7.2 years) the advantages of ADT were maintained [75].

Other studies compared combinations of goserelin, flutamide and finasteride [76], goserelin versus extramustine [77], goserelin versus cyproterone acetate [78]. No differences were found in the first two studies, a longer time to progression was found for goserelin compared to cyproterone acetate [78].

Leuprorelin
Localized prostate cancer

Several studies were performed with leuprorelin: three versus eight months of neoadjuvant therapy with leuprorelin [79], as add-on to surgery [80]. The medicine was also studied as add-on to radiotherapy [20, 81, 82].

PSA was reduced compared to surgery alone. Positive surgical margins and lymph node involvement were seen more often in the group with surgery alone [80]. A higher overall survival was seen compared to radiotherapy alone [81]. Another study showed no positive effects on quality of life [82].

Advanced prostate cancer

One study investigated the effects of leuprorelin or oral bicalutamide on bone mineral density (BMD). The results were more favourable for bicalutamide [83].

Studies comparing one and three months formulations showed no relevant differences concerning effects on testosterone levels and PSA [8487]. This was also the case for a comparison of three and six months formulations in a mixed population [88].

Leuprorelin prior to radical prostatectomy was compared to no pretreatment by a US study group. This study showed no differences in clinical relapse-free or PSA relapse-free survival rates between the groups [89, 90].

Triptorelin
Localized prostate cancer

One study compared preoperative triptorelin with no hormonal treatment in patients with localized prostate cancer. Triptorelin did not show favourable effects on postoperative PSA or skeletal events [91].

Advanced prostate cancer

One study compared triptorelin (+flutamide) with PEP. The primary endpoint was overall survival. No differences in mortality were observed at shorter or longer follow-up [9294]. The 28 days and 3 months formulations showed similar effects on testosterone, LH and PSA levels [95]. Use of triptorelin prior to prostatectomy resulted in a lower rate than the control group, but there was no effect on progression-free survival [9697].

Metastatic prostate cancer

Triptorelin was as effective as orchiectomy regarding effects on metastases and pain scores [98].

Although the levels of evidence were quite variable, no clinically meaningful differences were identified in clinical efficacy among buserelin, goserelin, leuprorelin and triptorelin in localized, advanced or metastatic prostate cancer. The clinical efficacy of goserelin and leuprorelin are much better documented than the other drugs.

It is not yet clear whether or not intermediate therapy with GnRH agonists is as safe and effective as continuous therapy [5].

All medicines are awarded 80%.

Safety
The incidence of severe adverse reactions was low for all compounds. Very few direct comparative studies between GnRH agonists and antagonists were identified. Agonists in general may induce depression, which can be severe. The incidence of severe adverse events was low to moderately high in most studies. The duration and size of most studies was insufficient to make firm statements concerning relative safety in the long term. There are no indications for major differences between the drugs concerning safety, with the exception of abarelix, which shows anaphylactic reactions at a higher rate than is the case with the other drugs.

Abarelix is awarded 60%, whereas the other medicines are awarded 70%.

Tolerability
Gonadotropin-releasing hormone (GnRH) agonists were associated with frequent, but harmless side effects. The side effects in direct comparative studies that are most relevant are summarized in Table 3.

The most common side effects result from the mechanism of action of the drugs, leading to impotence, decreased sexual drive and hot flushes. When GnRH agonists are given as monotherapy, testosterone surge may occur in the early phases of treatment.

Dosage frequency
A low dosage frequency is convenient to the patient and may increase compliance with therapy. The highest score (100%) was awarded to the lowest dose frequency (every six months), the lowest score (20%) was awarded to the highest dose frequency (every week). Scores for different dosage frequecies are given in Table 4. Leuprorelin was awarded 90%, because the generic formulation was included in the analysis. Six months formulations of goserelin and leuprorelin are not available in The Netherlands, but these are approved in other European countries. The dosage frequency of the agonists is more favourable than the antagonists.

User-friendly dosage forms
A user-friendly dosage form which is easy to store and handle is convenient to the patient and the caregiver. User-friendly scores ranged from 30% for drugs stored at room temperature to 15% for drugs stored in a refrigerator, and 0% for drugs stored below 0°C. Drugs that required no reconstitution had a score of 30%, drugs that needed complicated reconstitution had a score of 10%. Ease of administration ranged from 40% for easy, to 10% for complex. Score for different drugs are shown in Table 5.

The hybrid generic implant formulation of leuprorelin was used for calculation of the score. Eligard is not ready for use and needs to be reconstituted and kept in the refrigirator.

All agonists are given subcutaneously in a depot formulation. No independent studies comparing the ease of use of the implants are available. The ease of administration is better for the antagonists, as no implant has to be injected.

Drug interactions
No specific studies were performed. There are almost no known interactions with any of the GnRH agonists. Buserelin and goserelin may lower glucose tolerance, which could lead to decreased efficacy of antidiabetic medication.

Special precautions
Data were collected from the summaries of product characteristics (SPCs) for each drug. The warnings and precautions of the GnRH agonists are summarized in Table 6.

More special precautions are applicable to abarelix and degarelix. These drugs are awarded 60%. Although there are differences in the SPCs of the GnRH agonists, it is unclear whether this reflects real differences between the drugs. These medicines are given a score of 70%.

Documentation
The score for this criterion is divided into four sub-criteria: (1) number of randomized comparative studies; (2) number of patients in these studies; (3) number of years marketed; and (4) number of patient days worldwide.

The first two of these sub-criteria are indicative of the overall clinical documentation of the drugs in randomized controlled clinical studies. A large number of clinical studies and a large number of patients included in these studies leave no doubt about the clinical efficacy and safety of this drug in the studied population. The latter two criteria are indicative of the overall clinical experience with the drug. These sub-criteria may introduce a bias to the advantage of older drugs, but this is done intentionally. The safety of a newly introduced drug cannot be guaranteed from the results of clinical studies, in which only a relatively small number of patients were included and most patients at risk for the development of adverse reactions (e.g. patients with diminished renal function) were excluded. Both the number of patients that have been treated on a worldwide basis and the period that a certain drug has been available are of importance, as it may take time until adverse reactions occur. For a summary of these data, see Table 7.

The overall SOJA score is presented in Table 8.

Discussion

There is currently no major need to make formulary choices within the GnRH agonists and antagonists in most countries. The drugs are usually not included in the hospital formulary because they are primarily used outside the hospital. In The Netherlands, many expensive drugs will be transferred to the hospital budget in January 2015. This will lead to discussions concerning formulary selection, because the cost of these drugs will be the responsibility of the hospital. Therefore, there is a need for tools to aid formulary choices. We have not included the criterion acquisition cost, to allow for a pre-selection only on quality aspects. Only the drugs with the highest scores will be considered as options for the treatment of patients with prostate cancer. After completion of the study, it turned out that the medicines in the present analysis would not be transferred to the hospital budget in 2015.

The weighting of the selection criteria reflects the opinion of the authors. Of course, such opinions are always open for debate. Therefore, all existing SOJA productions are available on the Internet (www.tablet.sojaonline.nl), allowing each user of the method to assign his/her own relative weight to each criterion, thereby calculating a personal score [101]. None of the SOJA productions is financially supported by pharmaceutical companies.

Goserelin and leuprorelin show the highest scores. The main advantage compared with buserelin and triptorelin is the better documentation for the treatment of prostate cancer. Because the differences in score between goserelin and leuprorelin (and possibly triptorelin) are limited, these drugs are acceptable as first-line therapy. Clearly the judgement of the authors concerning the properties of the medicines has an impact on the final outcomes. There are however few indications that there are clinically relevant differences between the agonists regarding clinical efficacy, safety and tolerability.

It should be noted that the studies with leuprorelin were performed with various formulations, whereas this was not the case for the other medicines. A specification of the applied formulation was only provided in a few studies: Lupron [17, 83], Enantone [18] and Sandoz generic formulation [87]. The 16 other studies did not specify the formulation, although the vast majority of studies used a dose of 7.5 mg per 28 days or 22.5 mg per three months [10, 13, 16, 20, 79, 81, 86, 99, 102]. The 3.75 mg or 11.25 strengths were used in two studies [80, 89].

Acquisition cost plays a key role in the final selection of the drug of choice. The recent introduction of a generic leuprorelin implant formulation, which does not need reconstitution and can be stored outside of a refrigerator [87], and which is at least as effective as previously used leuprorelin formulations and was well tolerated in a relatively large group of patients (n = 818) [103] may be a good starting point for a renewed discussion on drug selection for the treatment of prostate cancer. Major cost savings might be applicable, because the acquisition cost of the various drugs has always been quite high. It seems likely that the need for a careful economic evaluation of drugs in oncology will increase throughout Europe.

Table 9 provides an overview of prices of the various agents in countries throughout Europe. The generic formulation is less expensive than the other medicines in most countries, with the interesting exception of The Netherlands. Prices are also quite different between countries, prices in Belgium are considerably lower than in other counties. Prices may be lower after negotiations between hospitals and companies.

The GnRH antagonists, degarelix and abarelix, show considerably lower scores than the GnRH agonists. Based on current data, these drugs should not be considered as first-line therapy for the treatment of prostate cancer. Their acquisition cost is also higher than those of (the already expensive) GnRH agonists. The 2013 guideline for the treatment of prostate carcinoma of the European Association of Urology assigned a limited place to GnRH antagonists: ‘Overall, this new family of agents seems appealing, but their advantages over GnRH agonists are far from proven. The use of GnRH antagonists is limited by a monthly formulation. Suppression of the initial flare-up with monotherapy is only clinically relevant in a few, symptomatic, metastatic patients’ [104].

Competing interests: Dr Rob Janknegt is the Deputy Editor-in-Chief and member of the Executive Editorial Board of the Generics and Biosimilars Initiative Journal (GaBI Journal). Niels Boone has nothing to declare. Dr Frans Erdkamp has participated in clinical trials funded by AstraZeneca. Dr Victor Zambon has nothing to declare.

Provenance and peer review: Not commissioned; externally peer reviewed.

Authors

Robert Janknegt, PharmaD, PhD, Hospital Pharmacist
Niels Boone, PharmD, Hospital Pharmacist
Frans Erdkamp, MD, PhD, Oncologist
Victor Zambon, MD, Urologist

Orbis Medisch Centrum, 1 Dr H van der Hoffplein, NL-6162 BG Sittard-Geleen, The Netherlands

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Author for correspondence: Rob Janknegt, PhamD, PhD, Hospital Pharmcist, Clinical Pharmacologist, Orbis Medisch Centrum, 1 Dr H van der Hoff plein, NL-6162 BG Sittard-Geleen, The Netherlands

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How to realize the potential of off-patent biologicals and biosimilars in Europe? Guidance to policymakers

Author byline as per print journal: Steven Simoens, PhD; Claude Le Pen, PhD; Niels Boone, PharmD; Ferdinand Breedveld, MD, PhD; Antonella Celano; Antonio Llombart-Cussac, MD, PhD; Frank Jorgensen, MPharm, MM; Andras Süle, PhD; Ad A van Bodegraven, MD, PhD; Rene Westhovens, MD, PhD; Jo De Cock

Introduction/Objectives: This manuscript aims to provide guidance to policymakers with a view to fostering a fair, competitive and sustainable market for off-patent biologicals and biosimilars in Europe.
Methods: Individuals and stakeholder representatives from patient groups, clinicians, healthcare professional organizations, government bodies, and industry participated in a series of roundtable discussions.
Results: Policymakers need to involve physicians and other stakeholders in designing smart procurement and reimbursement mechanisms that incite competition in the market for off-patent biologicals and biosimilars, and that guarantee the availability of choice between products. With respect to the demand-side, the clinical profession, academia and patients need to be involved in developing a prescribing and switching framework for off-patent biologicals and biosimilars. The physician prescribes an off-patent biological or biosimilar, or switches between products based on clinical judgement and high quality evidence. In this respect, hospital pharmacists provide a ‘hub of information’ about the uptake, real-world use and evidence based on off-patent biologicals and biosimilars. Other demand-side incentives, such as physician quotas, should not be introduced without examining the impact together with relevant stakeholders including medical professionals, patients and regulators in order to meet different policy goals. Pharmacist substitution should only be considered in well-defined circumstances, motivated by specific needs and informed by high quality evidence.
Conclusions: Policymakers need to introduce a long-term, multi-stakeholder, specific policy framework for off-patent biologicals and biosimilars.

Submitted: 6 June 2018; Revised: 13 July 2018; Accepted: 13 July 2018; Published online first: 20 July 2018

Introduction

Reference biologicals are originator medicinal products made by or derived from living organisms using biotechnology. When the patent and exclusivity rights on a reference biological expire, biosimilar medicines can enter the market. A biosimilar is a biological product that contains a version of the active substance of an already authorized reference biological medicinal product [1]. On the one hand, the European Medicines Agency (EMA) and regulatory authorities guarantee the quality, safety and efficacy of registered biosimilars. After a decade of experience with biosimilar products, no unexpected concerns have emerged [2, 3]. Also, health economists of international organizations refer to the important savings potential of a competitive off-patent biologicals and biosimilars market and to the opportunity to improve patient access. On the other hand, the market access, uptake and price evolution of off-patent biologicals and biosimilars stay heterogeneous between countries and between therapeutic classes, e.g. erythropoiesis-stimulating agents, granulocyte colony-stimulating factors, human growth hormones, antitumour necrosis factors, follitropin alfa and insulins [4].

This implies that European countries are not realizing the full potential of the off-patent biologicals and biosimilars market. In this respect, the European Commission and the Organisation for Economic Co-operation and Development (OECD) have argued that competition in the off-patent biologicals and biosimilars market could yield substantial savings to healthcare systems [5, 6]. To capture these savings, the European Commission (Directorate-General for Internal Market, Industry, Entrepreneurship and small and medium-sized enterprises [SMEs]) has supported a multi-stakeholder approach and has hosted multiple workshops with a view to facilitating access to and uptake of biosimilars [7, 8]. The European Commission also issued a consensus information paper in 2013, an information document for patients in 2016, and an information guide for healthcare professionals in 2017 [8].

However, the development of a competitive market for off-patent biologicals and biosimilars is not certain because of numerous factors including the risk of non-recognition of the difference between biosimilars and generics, physician and patient lack of confidence, and unbalanced payer pricing and procurement policies. In particular, after a decade of experience with these products, it seems clear that a simple logic whereby price reductions multiplied by prescribed volumes of reference biologicals will lead to potential savings is misleading and inappropriate. Price reductions alone do not appear to be the key factor guaranteeing greater market penetration of biosimilars [4]. On the contrary, price reductions can lead to a race to the bottom, preventing manufacturers to enter the market.

It is also important that policymakers keep in mind that biosimilars (where the reference product is a biological medicine) are inherently different from generics (where the reference product is a chemically synthesized medicine), due to their more elaborate size and structure of the molecule, higher risks and costs of research and development, more complex manufacturing processes, extended development times, and the need to institute post-marketing pharmacovigilance programmes [9]. Therefore, policy must be adapted to the specific needs of the off-patent biologicals and biosimilars market.

Developing a competitive market for off-patent biologicals and biosimilars in Europe is a necessary condition for stakeholders to reap the benefits that such competition may create. These benefits include more control of drug expenditure for healthcare payers, expanded access to health care for patients, increased treatment choices for physicians, and headroom for innovation for industry. The development of such a market requires the implementation of a long-term, sustainable and specific policy framework based on a multi-stakeholder approach. Thus, the aim of this manuscript is to provide guidance to policymakers with a view to fostering a fair, competitive and sustainable market for off-patent biologicals and biosimilars in Europe, taking into account the role of all stakeholders.

Methods

This manuscript has been commissioned by the Belgian National Institute for Health and Disability Insurance. Individuals and stakeholder representatives from patient groups, clinicians, healthcare professional organizations, government bodies, and industry have participated in a series of roundtable discussions in 2016–2017 which have contributed to the development of the manuscript. These discussions were held under Chatham House Rules. This manuscript represents the authors’ views on the topic which have been informed by their participation in the roundtable discussions and do not represent the position of their respective organization/institution.

When developing guidance to policymakers, the focus of this manuscript is specifically on those product classes for which patent expiry and loss of exclusivity has recently occurred or is imminent, such as monoclonal antibodies for the treatment of inflammatory diseases (rheumatoid arthritis, inflammatory bowel diseases, psoriasis) and cancers.

Results

Guidance to policymakers

Supply-side incentives
A building block of a fair, competitive and sustainable market for off-patent biologicals and biosimilars in Europe, see Box 1, relates to the need to put in place appropriate supply-side incentives. In particular, policymakers need to design smart procurement and reimbursement mechanisms with a view to allowing physicians to prescribe off-patent biologicals and biosimilars based on scientific evidence and clinical experience. The design of such mechanisms needs to be anchored in good clinical practice, which will evolve with knowledge, and needs to respect the European legislative framework on public procurement [10, 11]. Physician involvement in procurement and reimbursement mechanisms is vital to ensure that physicians maintain the freedom to prescribe. Also, there is a need to build up technical and practical expertise, and exchange experiences between countries with respect to designing smart procurement and reimbursement mechanisms.

Box 1: Recommendations for developing policy on off-patent biologicals and biosimilars in Europe

Supply-side incentives

  • Policymakers need to involve physicians and other stakeholders in the design of smart procurement and reimbursement mechanisms to ensure that such mechanisms are sufficiently flexible to permit the prescribing physician to act in the best interests of the patient, including the availability of choice between products.
  • There is a need to build up the technical and practical expertise, and exchange experiences between countries with respect to designing smart procurement and reimbursement mechanisms.
  • Although procurement and reimbursement mechanisms may generate price competition and produce short-term savings, policymakers also need to consider the possible impact of these mechanisms on the sustainability and the level of competition in the market for off-patent biologicals and biosimilars in the long run.
  • Tendering mechanisms can be applied to off-patent biologicals and biosimilars, but should avoid a ‘winner takes all’ approach as shortages may occur if that supply fails.
  • Policymakers need to appreciate that the application of a reference pricing system could imply that off-patent biologicals and biosimilars included in the same reference group could be used interchangeably. In such cases, the relevant policymaker should clarify the status of the medicine.

Demand-side incentives

  • The clinical profession, academia and patients need to be involved in developing a prescribing and switching framework for off-patent biologicals and biosimilars.
  • The physician prescribes an off-patent biological or biosimilar, or switches between products based on clinical judgement and high quality evidence, and based on shared decision-making with the patient. The physician’s freedom to prescribe also considers his/her therapeutic and budgetary accountability based on scientific evidence, clinical experience and expert judgement.
  • In order to make an informed and documented decision, physicians need to be supported by developing the evidence base around switching, including real-world data, pharmacovigilance data, switching data and outcome data.
  • Position statements issued by scientific and medical societies are a critical factor in supporting the appropriate use of off-patent biologicals and biosimilars.
  • Additionally, hospital pharmacists play an essential role by providing a ‘hub of information’ in respect of the uptake, good use and evidence base on off-patent biologicals and biosimilars (monitoring of outcomes, real-world use and reporting of adverse events).
  • Physician quota can be instrumental in developing a competitive and sustainable market for off-patent biologicals and biosimilars as far as the medical profession and other relevant stakeholders are formally involved in this process.
  • Pharmacist substitution should only be considered in well-defined circumstances, motivated by specific needs and informed by high quality evidence. If considering pharmacist substitution, any such policy needs to be designed in such a way that the prescribing physician is aware of and approves which specific product is dispensed, that pharmacists are trained to provide unbiased information about off-patent biologicals and biosimilars, and that patients are fully informed and agree with substitution.

Gainsharing

Experience needs to be gathered with the design and impact of gainsharing arrangements, which share the savings generated from off-patent biological and biosimilar competition between stakeholders, e.g. healthcare payers, hospitals, physicians and patients.

Box 1: Recommendations for developing policy on off-patent biologicals and biosimilars in Europe
In the hospital setting, tendering mechanisms, i.e. public procurement mechanisms for medicines based on competition between pharmaceutical suppliers [12], can be applied to off-patent biologicals and biosimilars nationally or locally, although future studies need to provide guidance to policymakers on how to optimize the features of these mechanisms, such as the frequency of tenders, the criteria to grant the tender, the reward for the winner(s), and the number of winners. For example, tendering may lead to a market where only one medicine is available, i.e. the ‘winner takes all’ principle, and shortages may occur if that supply fails. Thus, tendering mechanisms need to be monitored to ensure that several pharmaceutical suppliers participate and that the market does not fail [13].

In the ambulatory care setting, off-patent biologicals and biosimilars can be included in a reference pricing system, which sets a common reimbursement level for a group of medicines. Policymakers need to appreciate that the application of a reference pricing system could imply that off-patent biologicals and biosimilars included in the same reference group could be used interchangeably (which indicates that a patient can be alternated between products whilst expecting the same clinical outcomes in respect to efficacy and safety as if no alternation were to occur) [14]. In such cases, the relevant policymaker should clarify the status of the medicine.

If implemented, smart tendering mechanisms and/or reference pricing systems need to be sufficiently flexible to permit the prescribing physician to act in the best interests of the patient, including the availability of choice between products. In our opinion, this also implies that physicians are in charge of any switching protocols and that no forced switching occurs. Although procurement and reimbursement mechanisms may generate price competition and produce short-term savings, policymakers also need to consider the possible impact of these mechanisms on the sustainability and the level of competition in the market for off-patent biologicals and biosimilars in the long run.

Demand-side incentives
In our opinion, a key challenge relates to how physicians should use off-patent biologicals and biosimilars in real-life, clinical practice. It is clear that biosimilars can be administered to treatment-naïve patients in all approved indications. However, there is debate and concern about whether it is appropriate to introduce incentives that encourage patients to be switched from a reference biological product to a biosimilar; from one biosimilar to another biosimilar; and about switching on multiple occasions. Although such incentives purport to encourage price competition between manufacturers, there remains residual uncertainty and resistance from different stakeholders to these various forms of switching.

Therefore, we believe that the clinical profession, academia and patients need to be involved in the policy framework for off-patent biologicals and biosimilars, see Box 1. Due to the complex nature of off-patent biologicals and biosimilars, it is clear that the appropriate use of these products needs to be a clinical decision made by a treating physician for an individual patient on the basis of shared decision-making with that patient [15]. The decision needs to balance the physician’s freedom to prescribe with his/her therapeutic and budgetary accountability based on scientific evidence, clinical experience and expert judgement. In order to make an informed and documented decision, physicians need to be supported by developing the evidence base around switching, including real-world data, pharmacovigilance data, switching data and outcome data [16]. Scientific and medical societies have a particular responsibility to provide detailed guidance on appropriate use through position statements [17]. Furthermore, the role of hospital pharmacists is important as they provide a ‘hub of information’ in respect of the uptake, good use and evidence base (monitoring of outcomes, real-world use and reporting of adverse events).

A number of European countries have implemented other physician incentives, such as quota [18]. From those experiences applied in countries with social health insurance systems clearly results that sufficient success will only be realized as far as a formal involvement of the medical profession and other relevant stakeholders is put in place.

In Europe, pharmacist substitution, i.e. the practice of a pharmacist dispensing a different, but similar biological medicine other than that which was prescribed, is a Member State responsibility. Today, the majority of European countries do not favour pharmacist substitution of a biosimilar for a reference biological medicine, although several countries are experimenting with various pharmacist substitution policies [18]. Pharmacist substitution should only be considered in well-defined circumstances, motivated by specific needs and informed by high quality evidence. If a country would consider pharmacist substitution, policymakers need to ensure that any substitution policies guarantee that the prescribing physician is aware of and approves which specific product is dispensed, that pharmacists are trained to provide unbiased information about off-patent biologicals and biosimilars, and that patients are fully informed and agree with substitution.

Gainsharing
A third building block that can align different supply- and demand-side stakeholders in promoting a competitive and sustainable market for off-patent biologicals and biosimilars relates to the recent trend of ‘gainsharing’, see Box 1. Several European countries are experimenting with gainsharing arrangements, which share the savings generated from off-patent biological and biosimilar competition between stakeholders, e.g. healthcare payers, hospitals, physicians and patients [19]. For instance, savings can be invested in supporting physicians and nurses when switching patients or in providing additional services to patients. Today, the experience with gainsharing arrangements is limited and future studies need to investigate the optimal design and impact of such arrangements.

Conclusions

In our opinion, policymakers need to introduce a long-term, sustainable and specific policy framework based on a multi-stakeholder approach with a view to fostering a fair, competitive and sustainable market for off-patent biologicals and biosimilars in Europe. Although there exists residual uncertainty regarding the appropriate terms for switching off-patent biologicals and biosimilars, we believe that such issues will be clarified and resolved over the coming years with the development of new studies, data and experience with these products. Additionally, we advocate that a policy framework for the off-patent biological and biosimilar market needs to be founded on multiple building blocks including the implementation of supply- and demand-side incentives, and the prospective evaluation of gainsharing arrangements.

For patients summary

Competition among off-patent biologicals and biosimilars in Europe benefits patients as it may help to control drug expenditure, expand access to health care, increase treatment choices, and encourage pharmaceutical innovation. However, there remains uncertainty about switching patients from a reference biological product to a biosimilar; from one biosimilar to another biosimilar; and about switching on multiple occasions. Therefore, we believe that the clinical profession, academia and patients need to be involved in developing a policy framework for off-patent biologicals and biosimilars. Due to the complex nature of off-patent biologicals and biosimilars, it is clear that the appropriate use of these products needs to be a clinical decision made by a treating physician for an individual patient on the basis of shared decision-making with that patient.

Acknowledgements

The authors would like to thank John Bowis, Laura Batchelor and Johan Van Calster from FIPRA for facilitating and chairing the roundtable discussions.

Funding sources

This work was enabled by Amgen, MSD and Pfizer.

Competing interests: SS is one of the founders of the KU Leuven Fund on Market Analysis of Biologics and Biosimilars following Loss of Exclusivity. SS has previously conducted biosimilar research sponsored by Hospira (now Pfizer Inc); and has participated in an advisory board meeting on biosimilars for Pfizer Inc. NB and AvB declare no competing interests. RW is currently principal investigator for Galapagos/Gilead and Celltrion; and has received unrestricted research grants to the KU Leuven from BMS, Janssen and Roche.

Provenance and peer review: Not commissioned; externally peer reviewed.

Authors

Professor Steven Simoens, PhD
KU Leuven, Faculteit Farmaceutische Wetenschappen
Department of Pharmaceutical and Pharmacological Sciences
Onderwijs en Navorsing 2, bus 521 49 Herestraat
BE-3000 Leuven, Belgium

Professor Claude Le Pen, PhD
Paris Dauphine University LEGOS Laboratory of Economics and Management of Health Organizations
Place du Maréchal de Lattre de Tassigny FR-75775 Paris Cedex 16, France

Niels Boone, PharmD
Orbis Medical Center
Department of Clinical Pharmacy and Toxicology
PO Box 5500
NL-6130 MB Sittard-Geleen, The Netherlands

Professor Ferdinand Breedveld, MD, PhD
Professor of Rheumatology
European League Against Rheumatism Leiden University Medical Center EULAR/EMA Liaison
83a Rapenburg
NL-2311 GK Leiden, The Netherlands

Antonella Celano, President
Italian National Association of People with Rheumatological and Rare Diseases 16 Via Molise
IT-73100 Lecce (LE), Italy

Antonio Llombart-Cussac, MD, PhD
Medica Scientia Innovation Research (MedSIR ARO)
Barcelona, Spain

Hospital Arnau de Vilanova de Valencia Valencia, Spain

Frank Jorgensen, MPharm, MM
The Hospital Pharmacy Bergen
NO-5085 Bergen, Norway

Andras Süle, PhD
Chief Pharmacist
Péterfy Hospital and Trauma Center 8-20 Peterfy Sandor u
HU-1076 Budapest, Hungary

Ad A van Bodegraven, MD, PhD Gastroenterologist
Department of Gastroenterology, Geriatrics, Internal and Intensive Care Medicine (COMIK)
Zuyderland Medical Centre
PO Box 5500
NL-6130 MB Sittard-Geleen, The Netherlands

Department Gastroenterology
Amsterdam University Medical Centres (AUMC), location Vrije Universiteit
1117 De Boelelaan
NL-1081 HV Amsterdam, The Netherlands

Professor Rene Westhovens, MD, PhD
Professor of Rheumatology
University Hospital Leuven – Rheumatology
49 Herestraat
BE-3000 Leuven, Belgium

Rijksinstituut voor ziekte- en invaliditeitsverzekering
Jo De Cock, Administrator-General 211 Tervurenlaan
BE-1150 Brussels, Belgium

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Author for correspondence: Professor Steven Simoens, PhD, KU Leuven, Faculteit Farmaceutische Wetenschappen, Department of Pharmaceutical and Pharmacological Sciences, Onderwijs en Navorsing 2, bus 521, 49 Herestraat, BE-3000 Leuven, Belgium

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