320 Zdrav Vestn | maj – junij 2020 | Letnik 89 NeVrobioL ogija 1 Division of Paediatrics, University Medical Centre Ljubljana, Ljubljana, Slovenia 2 Department of Child, adolescent and Developmental Neurology, Division of Paediatrics, University Medical Centre Ljubljana, Ljubljana, Slovenia Korespondenca/ Correspondence: Tanja Loboda, e: tanja. loboda@kclj.si Ključne besede: spinalna mišična atrofija; otrok; naravni potek bolezni; zdravljenje ki spreminja potek bolezni Key words: spinal muscular atrophy; child; natural course of the disease; disease modifying therapy Prispelo: 16. 11. 2018 Sprejeto: 27. 3. 2020 @publisher.id: 2902 @primary-language: sl, en @discipline-en: Microbiology and immunology, Stomatology, Neurobiology, oncology, Human reproduction, Cardiovascular system, Metabolic and hormonal disorders, Public health (occupational medicine), Psychiatry @discipline-sl: Mikrobiologija in imunologija, Stomatologija, Nevrobiologija, Onkologija, Reprodukcija človeka, Srce in ožilje, Metabolne in hormonske motnje, javno zdravstvo (varstvo pri delu), Psihiatrija @article-type-en: editorial, original scientific article, r eview article, Short scientific article, Professional article @article-type-sl: Uvodnik, Izvirni znanstveni članek, Pregledni znanstveni članek, Klinični primer, Strokovni članek @running-header: Treatment with Nusinersen in a girl with Spinal Muscular a trophy Type 1 @reference-sl: Zdrav Vestn | maj – junij 2020 | Letnik 89 @reference-en: Zdrav Vestn | May – june 2020 | Volume 89 Treatment with nusinersen in a girl with spinal muscular atrophy type 1: Case report Zdravljenje z nusinersenom pri deklici s spinalno mišično atrofijo tip 1: Prikaz primera Tanja Loboda, 1 Tita Butenko, 2 Tanja Golli, 2 Damjan Osredkar 2 Abstract We report the case of a girl with spinal muscular atrophy (SMA) type 1, who is the first patient with SMA in Slovenia treated with nusinersen, the first disease modifying therapy available for these patients. SMA is an autosomal recessive neuromuscular disorder characterized by muscle weakness, atrophy and paralysis due to the degeneration of the anterior horn cells, leading to premature death, most commonly due to respiratory infections. Nusinersen, an antisense oligo - nucleotide, was clinically approved based on clinical trials showing dramatic improvement in the natural course of infantile-onset SMA. After the genetic confirmation of SMA, our girl was the first child in Slovenia to receive nusinersen, which was provided through an expanded access programme. She received intrathecal applications of nusinersen according to the protocol. No serious adverse events were observed. Assessment of her motor skills was performed using The Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP – INTEND) be- fore the beginning of treatment and after completing the first 7 applications of nusinersen. She scored 21/64 points before the introduction of treatment and 32/64 after the completion of tre - atment. In conclusion, nusinersen improved the CHOP – INTEND motor function score and has been effective in delaying the expected natural course of SMA in our patient. Izvleček Predstavljamo primer deklice s spinalno mišično atrofijo (SMA) tipa 1, prve bolnice v Sloveniji, ki se zdravi z zdravilom nusinersen, ki spreminja naravni potek bolezni. SMA je avtosomno rece - sivna živčno-mišična bolezen, za katero je značilno propadanje motoričnih nevronov sprednjih rogov hrbtenjače, kar vodi v mišično šibkost, atrofijo, paralizo in prezgodnjo smrt; slednja je v večini primerov posledica okužbe dihal. Protismiselni oligonukleotid nusinersen je bil odobren za zdravljenje na osnovi kliničnih študij, ki so pokazale izboljšanje v naravnem poteku infantilne oblike SMA. Po genetski potrditvi klinične diagnoze SMA je naša deklica prvi otrok v Sloveniji, pri kateri smo uvedli zdravljenje z nusinersenom. Zdravilo smo, še pred registracijo v Sloveniji, dobili s pomočjo programa sočutne rabe. Deklica v skladu s protokolom prejema redno intrate - kalno nusinersen. Neželenih učinkov ob zdravljenju nismo beležili. Objektivno oceno dekličinih motoričnih sposobnosti smo opravili s pomočjo lestvice CHOP – INTEND pred začetkom in po sedmih vnosih zdravila nusinersen. Deklica je pred uvedbo zdravljenja dosegla 21/64 točk, po sedmih vnosih zdravila pa 32/64 točk. Ugotavljamo, da je nusinersen, glede na lestvico CHOP – INTEND, izboljšal motorične sposobnosti pri naši deklici in se je pri upočasnjevanju naravnega poteka bolezni izkazal kot učinkovit. Citirajte kot/Cite as: Loboda T , butenko T , golli T, osredkar D. Treatment with Nusinersen in a girl with Spinal Muscular Atrophy Type 1 – Case report. Zdrav Vestn. 2020;89(5–6):320–26. DOI: 10.6016/ZdravVestn.2902 Treatment with Nusinersen in a girl with Spinal Muscular a trophy Type 1 321 KlInIčnI PRIMeR 1 Introduction Spinal muscular atrophy (SMA) is an autosomal recessive disease chara- cterized by the degeneration of anterior horn cells, resulting in muscle atrophy and weakness (1). It is classified into five types based on clinical features, age of onset and the motor functions affected. In all five types of SMA involvement of virtually all skeletal muscles is present, with the exception of the muscles inner- vated by the first 11 cranial nerves (the XII cranial nerve being an exception among them) (2,3). The disease is most commonly caused by a mutation in the survival motor neu- ron (SMN) gene, located on chromosome 5 (5q11.2–13.3). This results in the loss of alpha motor neurons in the ventral horn of the spinal cord, resulting in progressi- ve paralysis and eventually premature death (4). The aforementioned mutation accounts for up to 95 % of cases and has a frequency of 1/11.000 births (5,6). In hu - mans, two forms of the SMN gene exist on each allele: a telomeric form (SMN1) and a centromeric form (SMN2). Transcription of the SMN1 gene produ- ces full-length mRNA transcripts that en- code the SMN protein. The SMN2 gene is identical to the SMN1 gene with the exception of a C to T substitution in an exonic splicing enhancer, which results in the exclusion of exon 7 during tran- scription. The resultant truncated prote- in is not functional and is rapidly degra- ded. Importantly, exon 7 is not excluded from all SMN2 mRNAs and so a small fraction of the total mRNA transcripts (~10–15 %) arising from the SMN2 gene does contain exon 7, thus encoding a normal SMN protein (7). Nusinersen is the first drug approved to treat SMA. It is a 2’-O-methoxyethyl phosphorothioate-modified antisense drug specifically designed to alter spli- cing of SMN2 pre-mRNA and thus in- crease the amount of functional SMN protein, which is deficient in patients with SMA (8). There are many studies evaluating the successfulness of the nusinersen treatment for different types of SMA. NURTURE, an open-label study that began in 2015 and is still ongoing, is assessing the efficacy, safety, tolerabi- lity and pharmacokinetics of multiple intrathecal doses of nusinersen admini- stered to presymptomatic SMA infants aged less than 6 weeks. The interim re- sults of the study show that the effects of nusinersen are encouraging with impro- vement in motor milestones and growth parameters, no fatalities and no ventila- tion required after 323 days (9). Mercuri et al. conducted a multicen- ter, double-blind, sham-controlled, pha- se 3 trial of nusinersen in 126 children with SMA who had symptom onset after 6 months of age. They concluded that among children with later-onset SMA, those who received nusinersen had sig- nificant and clinically meaningful imp- rovement in motor function, compared to those in the control group (10). Short term results that show the successfulness of nusinersen in late onset SMA were also obtained by other study groups (10,11), but for long term effects additional stu- dies and clinical trials are needed. Known adverse effects of treatment with nusinersen are side effects due to lumbar puncture (headache, back ache, vomiting), and rarely thrombocytope- nia, coagulation disturbances, renal toxi- city, and communicating hydrocepha- lus (12). SMA type 1 is the most common (50–60 %) type. By definition, the onset of symptoms in SMA type 1 is before 6 months of age and the main cause of 322 Zdrav Vestn | maj – junij 2020 | Letnik 89 NeVrobioL ogija mortality in these children is a result of respiratory involvement. From the point in time of diagnosis, infants with SMA type 1 rarely achieve improvement in motor function or acquire new motor developmental milestones (13). 2 Case report A 9–month-old girl presented to our hospital (University Children’s Hospital in Ljubljana, Slovenia) with gross motor delay, hypotonia and diminished sponta- neous movement in the lower limbs. She was born to healthy, non-con- sanguineous parents, with an unremar- kable family and antenatal history. She was born at 39 weeks of gestation, with a birth weight of 2610 g (7 th percentile), a birth length of 46 cm (5 th percentile), a head circumference of 33 cm (23 rd per- centile) and APGAR scores of 9/10/10. During her first 2 months of life poor weight gain was observed. She was bre- astfed for the first 7 weeks of life, there- after she was fed with a hypoallergenic formula due to skin rashes, gastroesop- hageal reflux and abdominal cramps, but weight gain was suboptimal. Until the 4 th month of life the parents reported normal development, she was able to prop herself up on her arms and lift her chin when in prone position. After that, the parents began to notice that the child had signs of muscle weak- ness and fewer spontaneous movements in her legs. At presentation to our insti- tution (at 9 months of age) they reported that she was able to sit unsupported, but was not able to sit up independently. The parents said that her upper limbs and cognitive functions were unaffected; she was able to grasp toys and move them from one hand to the other, she had babbling conversation from 7 months of age and good social contact. They repor- ted no problems with feeding or lower respiratory tract infections. On first examination, social conta- ct was good, she was smiling. Tongue fasciculations were present with no si- gns of other cranial nerve involvement. Hearing tests were not performed, but there were no clinical signs of impaired hearing; her newborn hearing screening test had been normal. When presented with a small toy, she reached toward it, grasped it with the forearm in internal rotation and a pincer grasp. She moved the object spontaneously from one hand to the other, without dropping it. There were almost no spontaneous movements of the lower limbs. Severe generalized hypotonia was present and lower limb muscle strength was severely dimini- shed. She had no obvious signs of mu- scle atrophy, but proximal muscle weak- ness was present in the upper and lower limbs, the latter were more affected. All deep tendon reflexes were absent. She was not able to roll from prone to supi- ne and back. When lying supine, frog-leg position was seen. When pulled to sitting position, she had no obvious head lag and was able to sit unsupported with thora- columbar kyphosis. In ventral suspensi- on, her lower limbs hung loosely and she was unable to support her weight when placed in standing position. Otherwise her clinical status was normal and her weight and length were normal for her age (10 kg – 94th percentile and 70 cm – 48th percentile). 2.1 Laboratory findings, diagnostic procedures and genetic study findings Diagnostic workup included comp- lete blood count and biochemistry, liver and muscle enzymes were done and they were all normal for age. Treatment with Nusinersen in a girl with Spinal Muscular a trophy Type 1 323 KlInIčnI PRIMeR Her pulmonary function tests and echocardiogram at presentation were normal. Night polygraphy was also per- formed, the recording lasting 5 hours and 51 minutes, with an average satura- tion of 94.6 %. It also showed periods of diminished blood oxygen saturation in sleep, lasting up to 2 minutes. Saturation below 90 % was present in 0.1 % of the recording. Because of technical difficul- ties, it was impossible to say whether the desaturations were of central or obstru- ctive origin. But it was postulated, that these results might be the result of hypo- ventilation or paradoxical breathing and further close follow-up was planned. Genetic studies revealed a homozygo- us mutation in SMN1 gene – the deleti- on of exon 7 and 8 - and four copies of SMN2 gene, which confirmed the dia- gnosis of SMA. 2.2 Treatment and follow-up The girl was the first child in Slovenia to receive nusinersen, which was provi- ded through an expanded access pro- gramme. For the purpose of regular fol- low-up and collection of all the relevant data she was included in the Registry of Slovenian Children with Neuromuscular Diseases, after written consent from her parents had been obtained. She had mul- tidisciplinary clinical assessments prior to starting treatment. She was given the 1st intrathecal application of nusinersen in the dosage of 11.3 mg under general anaesthesia on 7 March 2017 at the age of 14 months. Intrathecal injections with nusinersen were continued according to the proto- col – on treatment days 15, 30, 60 and 180 and thereafter every four months; only the first application was given under ge- neral anaesthesia. After each application, she received one dose of analgesic. So far, she has received 8 applications, the dosage being adjusted to 12 mg after the age of two. The first (and only) adverse effect was observed a few hours after the 6th appli- cation, when the girl reported symptoms of headache which subsided after the second dose of paracetamol. Assessment of her motor skills was performed using The Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP - INTEND) (14) before the beginning of treatment and after completing the first 7 applications of nusinersen. CHOP – INTEND is a reference test used in chil- dren with SMA, which evaluates sponta- neous as well as active movements of the upper and lower limbs and also head and neck control. She scored 21/64 points be- fore the introduction of treatment and 32/64 after the completion of treatment. The child was clinically and neurologi- cally evaluated by the neurologist before every application of nusinersen; her mo- tor skills as well as her general well-be- ing were recorded. The parents reported improved mobi- lity performance after the 3rd application of nusinersen. They noticed increased muscle strength and more spontaneo- us movements of lower limbs as well as the capability of lifting her upper limbs above her shoulders. Additionally, they also noticed improvement in head con- trol and reported the child was able to sit independently for 30 minutes. One hundred and eighty days after the intro- duction of treatment they reported inde- pendent rolling to the side, she was able to move her legs, support her weight and bounce when placed in the standing po- sition. At the age of two and a half years, the child was tested at our institution, where we documented 20 minutes of unassis- 324 Zdrav Vestn | maj – junij 2020 | Letnik 89 NeVrobioL ogija ted sitting without kyphosis. (Figure 1 ). She was able to dorsiflect and extend the foot, could activate extensors and abductors of the hips and when motiva- ted, could roll from prone to supine and from supine to the side. She did not show any decrease in her motor functions and there was no regression in the sponta- neous movements of the upper limbs. Deep tendon reflexes in lower limbs were still absent, but in the upper limbs, the biceps tendon reflex was present. She had had no serious respiratory infecti- ons (which we defined as any respiratory infection of the lower respiratory tract), her respiratory function as well as night polygraphy were normal, with no signs of hypoventilation or paradoxical breat- hing. She had had no feeding problems and had gained weight normally. 3 Discussion We report the first child with SMA type 1 in Slovenia, who was treated with nusinersen. Most infants with SMA type 1 are unable to achieve or maintain most motor milestones. In the natural cour- se of infantile onset SMA, regression of motor functions in all children is obser- ved with age and most of the children die within the first two years of life (15). In our patient, we observed no regressi- on of the achieved motor functions during treatment and after completi- on of first 7 applications of nusinersen, furthermore, she achieved new develo- pmental milestones. The girl was able to sit unsupported, without kyphosis, de- veloped the ability to roll spontaneously from prone to supine position, and was Figure 1: Girl with spinal muscular atrophy type 1 at the age of 33 months. She is the first patient with SMA in Slovenia treated with nusinersen, starting at the age of 14 months. She can sit by herself, can feed herself and can lift objects against gravity, which far exceeds the expectations based on the natural history of the disease. Treatment with Nusinersen in a girl with Spinal Muscular a trophy Type 1 325 KlInIčnI PRIMeR able to support her weight when placed in the standing position. She could ra- ise her arms above shoulder level and showed a wider range of movement in her upper limbs in general, was capable of grasping objects, including achieving the pincer grasp. A wider range of mo- vement of the lower limbs was also ob- served, including dorsiflexion, extension of the foot and activation of extensors and abductors of the hip. She could feed herself independently. Improvement of her motor skills was also observed on CHOP – INTEND, she improved by 11 points since the start of treatment. No serious respiratory infections were recorded. Her pulmonary function valu- es remained normal, she had no signs of hypoventilation, no need for ventilatory support and no feeding difficulties. On the follow-up, her night polygraphy was normal. The girl has 4 copies of SMN2 gene, which is more than normally seen in SMA type 1 patients, however it had been documented before (16). Despite having more copies of SMN2 gene, she presented with regression of her motor functions before the age of 6 months. We know that the number of copies of the SMN2 gene does not define the SMA type and does not necessarily cor- relate with the severity of clinical phe- notype. Nevertheless, having 4 copies might be a contributing factor to the fact that she is doing very well on the therapy with nusinersen, as nusinersen acts on SMN2 gene. Having more copi - es of this gene might contribute to the production of more functional SMN protein and therefore maintaining more alpha motor neurons in the spi- nal cord. She has tolerated nusinersen very well, as no serious adverse events have been observed. After the completion of 7 applications, the girls’ cardiopulmonary function is still normal. From our ob- servation, and taking into consideration the expected natural course of untreated SMA type 1, we consider that the tre- atment with nusinersen has been effecti- ve in delaying the natural course of SMA in our patient. The girls’ response to treatment, as well as data from international studi- es (11,13), have contributed to obtaining support from the Slovenian health care system to fully cover the financial bur- den of treatment with nusinersen for all paediatric (0–18 years of age) patients with SMA regardless of the type. We have agreed to closely follow the deve- lopment of all SMA patients treated and stop the treatment in those who fail to respond favourably to treatment. It still remains unclear how nusinersen will change the course of the disease in the long-term. Will the treatment give dura- ble results or will we still see a progressi- on of the disease, but at a slower rate? Are there other factors which contribute to the range of effect in treatment with nusinersen (like the number of SMN2 copies or other genetic factors)? These are the questions that call for further research and long-term follow-up of all treated patients. For now, all patients with a stable motor-developmental sta- tus or those who show further impro- vement, like our patient, will continue with the nusinersen treatment and clo- se follow-ups. Hopefully, by collabora- ting with other centres treating patients with SMA and sharing our experiences and data, we will be able to offer opti- mal treatment and achieve favourable outcomes in patients with SMA in the long run. Consent was obtained from the girl’s parents for the publication of this case report. 326 Zdrav Vestn | maj – junij 2020 | Letnik 89 NeVrobioL ogija References 1. Sugarman ea, Nagan N, Zhu H, akmaev Vr, Zhou Z, r ohlfs eM, et al. Pan-ethnic carrier screening and pre- natal diagnosis for spinal muscular atrophy: clinical laboratory analysis of >72,400 specimens. eur J Hum Genet. 2012;20(1):27-32. 2. Koul r, al-Futaisi a, al-Thihli K, bruwer Z, Scott P. Segmental Spinal Muscular a trophy Localised to the l ower limbs: first case from Oman. Sultan Qaboos Univ Med J. 2017;17(3):e355-7. 3. l unn MR, Wang CH. Spinal muscular atrophy. lancet. 2008;371(9630):2120-33. 4. Zanetta C, riboldi g, Nizzardo M, Simone C, Faravelli i, bresolin N, et al. 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