WHITE PAPER Individualized Controlled Ovarian Stimulation: Biomarker-Guided Treatment Personalization Author: Antonio La Marca, MD, PhD, Clinica Eugin and University of Modena and Reggio Emilia, Modena, Italy Antonio La Marca is a Professor of Obstetrics and Gynecology at the University of Modena and Reggio Emilia, as well as a coordinator of clinical activity at Clinica Eugin in Modena, Italy. Prof La Marca s clinical activity broadly covers the field of Reproductive Medicine and Surgery. His current scientific interests revolve around ovarian reserve and the pharmacological manipulation of ovarian activity. He has authored or co-authored more than 160 articles published in peer-reviewed journals, as well as several chapters of national and international textbooks. Prof La Marca has been an invited speaker at more than 100 international congresses. He has also been a Principal Investigator for a number of Phase 3 and 4 trials, as well as a recipient of several research grants. He is an active member of many national and international professional and scientific societies, and a consultant on infertility-related issues for the Italian Ministry of Health. Acknowledgements The scientific content and opinions presented in this paper are solely the views of Prof Antonio La Marca. The author thanks Ileana Stoica, PhD and Antonio Alvau, PhD from Green Park Content for their assistance in writing the manuscript. Financial support to Green Park Content was provided by Merck KGaA, Darmstadt, Germany. DISCLOSURE Honoraria for lectures and unrestricted research grants from Merck, MSD, Ferring, TEVA, IBSA, Beckman-Coulter, and Roche. A combination of biomarkers might increase clinicians predictive ability [...] and their ability to identify those patients at risk of poor or hyper ovarian response. Biomarkers: key tool of modern medicine Biomarkers have been defined as a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention [1]. Due to their predictive power, biomarkers are used in modern medicine to support disease diagnosis and prognosis; guide the choice of targeted therapy [2]; define treatment response; assess the potential for drug-drug interactions; and adjust drug doses to optimize the benefit/risk profile [3]. The availability of biomarker testing has helped to reduce patients exposure to ineffective experimental treatments and identify surrogate outcomes for clinical trials [1]. 1 Biomarkers for Individualizing ART
Biomarkers and Assisted Reproductive Technologies (ART) In assisted reproduction, the diversity of the patient population and the expanding number of treatment options have created both a need and an opportunity for personalizing treatment [4]. Similar to other fields, reproductive medicine benefits from the use of biomarkers to evaluate the inter-variability between different sub-fertile populations and match the correct treatment plan to the individual patient profile [4]. IVF after a single cycle [7]. While the physical and psychological burden of treatment was the main cause of drop-out, 6% of those who discontinued did so due to inadequate response to treatment [7]. In my daily clinical activity, I always try to personalize the treatment for each patient [...] by choosing between different GnRH analogues [...] different types of gonadotropin and, most importantly, selecting the FSH starting dose. Biomarker-guided strategies for optimizing ovarian stimulation Need for treatment personalization One of the main roles of biomarkers in ART is to support an individualized approach to ovarian stimulation, which can offer women the optimal treatment regimen according to their characteristics while minimizing iatrogenic risks such as Ovarian Hyperstimulation Syndrome (OHSS) [5]. Biomarkers are being utilized to define the right drugs and doses for the right patient, thus maximizing the safety and efficacy of ART, including in the context of individualized Controlled Ovarian Stimulation (icos) [6]. The starting dose of gonadotropins is a key factor determining the outcome of Controlled Ovarian Stimulation (COS) and of overall IVF success [5]. Using a one size fits all strategy, with a standard gonadotropin dose, has been associated with a high degree of inter-individual variability in ovarian response rates, including abnormal (hypo or hyper) responsiveness [5]. This contributes to the high rate of treatment discontinuation observed in fertility patients: a Dutch study found that 9% of couples abandon Markers of ovarian reserve Ovarian reserve is defined as the number and quality of follicles left in the ovaries at any given time [8]. While the age of a woman is typically a good predictor of her ovarian reserve, and thus of COS response, the extent to which ovarian reserve declines with age varies considerably. The use of predictive biomarkers in addition to age can help identify patients with diminished or adequate reserve and tailor the treatment dose to maximize oocyte retrieval and thus the ART yield in each of these groups [8, 9]. Historically, a number of markers of ovarian response have been associated with ovarian reserve, including age, body weight, and hormonal biomarkers such as circulating Follicle Stimulating Hormone (FSH) and inhibin-b. However, since these are indirect markers of ovarian reserve, their predictive power is limited and varies substantially among patients or within the menstrual cycle of a single patient [9]. A tale of two markers Clinical evidence accumulated over the past decade or so has made a compelling argument for the use of antral follicle count (AFC) and anti-müllerian hormone (AMH) as preferred markers of ovarian reserve [9]. 2 Biomarkers for Individualizing ART
AFC is a functional biomarker measuring the number of antral follicles, as detected by transvaginal ultrasound [4]. The AFC analysis is relatively easy to perform, non-invasive, widely accessible in clinical practice, and provides immediate results [9]. However, the number of follicles identified is sonographer- and operator-dependent, which may impact standardization of results in multi-center trials [9-11]. Granulosa cells secrete AMH during the early stages of follicular maturation; therefore, circulating levels of this hormone are associated with the number of recruitable pre-antral and early antral follicles [10, 11]. Despite some variability within and between cycles, which is consistent with its physiological role in follicle development, the AMH assay has good consistency and reproducibility, and can be performed at any time during the menstrual cycle [9]. However, unlike AFC, it does not provide results in real time. Furthermore, the lack of an international standard means the measurements from different commercially available assays might be inconsistent, limiting the reliability of AMH as a biomarker [9, 11]. Clinical context A prospective study on 42 healthy women undergoing oophorectomy for benign indications established that the ovarian AFC and serum levels of AMH were significantly correlated with the ovarian primordial follicle number [12]. The same study found a weak albeit significant relationship between FSH and follicle numbers, which may explain the superiority of AFC/AMH over the older biomarkers [12]. From a clinical viewpoint, the superior predictive ability of AFC/AMH vs. traditional markers was confirmed in systematic reviews of clinical studies in infertile patients [5, 8, 13]. For example, an analysis of 41 and 25 studies investigating the predictive power of AMH and AFC, respectively, demonstrated that both markers were superior to FSH, allowed for the prediction of the entire spectrum of ovarian response, and could be used interchangeably in clinical practice [5]. In the past, we mainly used fixed doses of gonadotropins in our IVF patients, or sometimes we just looked at female age [...] but this is not completely correct because ovarian response is largely dependent on ovarian reserve. [...]. That is why you must personalize the treatment. In order to personalize the treatment dose, ovarian reserve must be measured for each patient [...] using the best markers available, AMH and AFC. Biomarker-guided dose tailoring in clinical practice Both AFC and AMH are relevant in clinical practice and are used individually as well as in combination [5]. Furthermore, clinical evidence to date suggests an important role for both biomarkers in the fine-tuning of gonadotropin doses and the development of personalized COS protocols [5, 14]. A number of post-hoc analyses of randomized controlled trials (RCTs) indicated that using a single marker, rather than both in combination, may be sufficient in clinical practice [15, 16]. At the same time, it must be recognized that women with extremes of ovarian reserve are typically not enrolled in RCTs, leading to gaps in our current understanding of treatment response patterns in real-world IVF patients. Real-world studies to date have confirmed the superiority of AFC/AMH to traditional markers, while also suggesting that combining the two may improve the overall predictive ability compared with using either biomarker alone [17]. Based on the cumulative evidence for the utility of AFC and AMH, two nomograms for calculating the FSH starting dose have been developed, based on either AMH or AFC plus age and Day 3 serum FSH (d3fsh) levels. In both models, AMH and AFC were found as the leading predictor. However, the introduction of d3fsh and age in the calculation improved prediction accuracy nonetheless [14, 18]. 3 Biomarkers for Individualizing ART
Emerging results and outstanding questions A recent multi-center, non-inferiority RCT compared clinical outcomes in 1,326 women randomized 1:1 to receive individualized, AMH-based follitropin delta or fixed-dose (150 IU) ovarian stimulation with follitropin alfa [19]. The trial showed similar efficacies for the two interventions, as measured by the primary endpoint of ongoing pregnancy rate. However, analysis of secondary outcome measures revealed that fewer women receiving an individualized FSH dose had extreme ovarian responses than those in the fixed-dose group. No difference in all-grade OHSS between treatment arms was observed, although women treated with individualized follitropin delta had a reduced need for OHSS preventive measures [19]. These results strengthen the argument for individualizing the FSH starting dose using biomarkers, as a way to reduce the rates of low and high responders and the need for OHSS-preventive strategies. In addition, these findings appear to be related to the treatment strategy dose personalization and not the type of FSH used. The selection of the FSH starting dose is a key factor affecting the outcome of COS. 1 FSH dosage nomograms make use of three variables: age, Day 3 serum FSH dose, and a marker of ovarian reserve either AFC or AMH to individualize the FSH starting dose to the patient characteristics. 2,3 63% VS. 42% of women in the nomogram group of women in the control group* 4 Frequency 20 18 Optimal response 16 14 12 10 8 6 4 2 0 1 8 14 Number of oocytes Frequency of retrieved oocytes in the nomogram group and control group. A recent RCT with follitropin alfa showed that using a nomogram to select the FSH starting dose resulted in a significant increase in the proportion of patients with the target number of retrieved oocytes.** 4 * P=0.0037 ** Defined as 8-14 oocytes AFC=antral follicle count; AMH=anti-Müllerian hormone; COS=controlled ovarian stimulation; FSH=follicle stimulating hormone. 1. La Marca A and Sunkara SK. Hum Reprod Update 2014;20:124 140; 2. La Marca A, et al. J Ovarian Res 2013;6:11; 3. La Marca A, et al. BJOG 2012;119:1171 1179; 4. Allegra A, et al. Reprod Biomed Online 2017. doi: 10.1016/j.rbmo.2017.01.012. 4 Biomarkers for Individualizing ART
Indeed, a recent RCT confirmed that individualizing the FSH starting dose in IVF/ICSI cycles, compared to fixed-dose stimulation based on age and using the same compound, had a measurable impact on treatment outcomes [20]. In this two- arm, prospective trial of 194 couples attending their first IVF/ICSI in the clinic, patients were randomized to receive either a fixed starting dose of follitropin alfa or an individualized dose of follitropin alfa using an AMH-based nomogram. The proportion of patients with target ovarian response, defined as 8 14 retrieved oocytes, was 63% in the nomogram group and 42% in the control group, a difference that was statistically significant (P=0.0037) [20]. Furthermore, clinical pregnancy rates per embryo transfer were 48% in patients with target ovarian response vs. 27% in those not achieving the target ovarian response [21]. While further research is needed to assess the effects of a biomarker-guided, personalized approach on live birth outcomes, these results suggest that tailoring the FSH starting dose with the help of biomarkers can be a valuable strategy for optimizing COS outcomes. Toward an integrated perspective on fertility biomarkers A wealth of evidence accumulated over the past decade supports the use of fertility biomarkers to optimize ART outcomes. Both AFC and AMH have a role in predicting ovarian response and guiding treatment decisions [5, 9]. Nomograms based on AFC/AMH have been developed to tailor the starting dose of gonadotropin, a strategy that has been shown to improve COS outcomes while decreasing risk for patients [5]. Due to recent advances in the underlying technologies, the standardization issues that have limited the use of AMH and AFC in the past may soon be overcome, leading to a synergistic approach that utilizes both biomarkers in the fertility treatment algorithm [9, 10]. Future treatment algorithms may employ a truly integrated strategy that combines a range of markers to design COS protocols that meet individual patient characteristics and treatment needs [4]. AMH and AFC are widely used in clinical practice [...] and recently an Italian survey showed that 89% of Italian clinicians measure both AMH and AFC to personalize treatment, prevent OHSS, improve clinical performance [...] and reduce drop-out. 5 Biomarkers for Individualizing ART
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