Switching OnabotulinumtoxinA to Monoclonal Anti-CGRP Antibodies in Drug-Resistant Chronic Migraine

BACKGROUND

OnabotulinumtoxinA (BTX-A) and anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (anti-CGRP mAbs) are approved drugs for chronic migraine (CM), a difficult-to-treat condition. Optimization of CM patient management by choosing the best options and determining appropriate time for switching or adding concomitant treatments are highly needed.

OBJECTIVE

Evaluate clinical response to anti-CGRP mAbs in patients who switched from BTX-A due to ineffectiveness defined by different cut-offs and assess the retention rate, effectiveness, and safety of both drugs within the first 9 months of treatment.

METHODS

A monocentric, cohort study, enrolling patients with CM, resistant to several preventive treatments, first treated with BTX-A and then with anti-CGRP mAbs with two observational phases of 9 months preceded by respective baseline. First, the retention rate and effectiveness of both treatments were measured in all patients. A second analysis assessed effectiveness in patients stratified according to <50 or <30% response rate to BTX-A. The absolute change from baseline in monthly headache days (MHDs), response rate, analgesic use, and persistence in medication overuse (MO) at 3, 6, and 9 months of treatment were recorded. Last observation carried forward (LOCF) analyses, including all patients and assuming no further changes after discontinuation, were performed for all outcomes.

RESULTS

Of the 78 enrolled patients (80.8% female, and 89.7% with MO at baseline), 32 (41.0%) received erenumab, 32 (41.0%) galcanezumab, and 14 (18.0%) fremanezumab. Retention rate was 62.2 and 91.0% for BTX-A and 76.9 and 96.2%, for anti-CGRP mAbs at 3 and 9 months of treatment, respectively. At 9 months of treatment, 22.4% of BTX-A patients and 65.0% of anti-CGRP mAbs patients achieved a ≥50% response rate. Anti-CGRP mAbs reduced MHDs, AMN, and AMDs, and decreased the number of MO patients at 9 months. In patients stratified according to <50 or <30% response rate to BTX-A, response rate (≥50% response at 9 months) to anti-CGRP was 62.9 and 57.9%, respectively. LOCF analyses confirmed these findings. No serious adverse events (AEs) were recorded and only two patients discontinued treatment due to AEs.

CONCLUSIONS

Difficult-to-treat CM patients who discontinued BTX-A and received anti-CGRP mAbs showed a substantial clinical improvement in migraine-related outcomes. Switching to an anti-CGRP mAb appears to be a viable option in patients with insufficient response after the first 2 cycles with BTX-A. The appropriate variables, cut-offs, and timing to define ineffectiveness and the best time to switch or combine therapies for difficult-to-treat CM need to be investigated further.

Effectiveness of anti-CGRP monoclonal antibodies on central symptoms of migraine

BACKGROUND

Clinical trials and observational studies with anti-calcitonin gene-related peptide antibodies poorly investigated their impact on migraine prodromal and accompanying symptoms. This information might help deciphering the biologics' pharmacodynamic and provide hints on migraine pathogenesis. Herein, we report the effects of erenumab, fremanezumab and galcanezumab on attack prodromal and accompanying symptoms and on neurological and psychiatric traits. .

METHODS

An explorative, prospective, questionnaire-based study was completed by a cohort (n = 80) of patients with chronic migraine patients presenting a sustained reduction of ≥50% of Migraine Disability Assessment Score and ≥30% of monthly migraine days three months after anti-calcitonin gene-related peptide antibodies treatment.

RESULTS

The majority of patients experienced a complete prevention of migraine symptoms without evidence of initial onset followed by attack abortion. Few patients reported the recurrence of prodromal (from 10% to 12.5%) or accompanying (from 1.3% to 8.8%) symptoms without headache. All patients with migraine with aura reported a decrease of aura incidence. Sleep changes (51.2%), increase in appetite (20.0%) and weight (18.8%) as well as a reduction in stress (45.0%), anxiety (26.3%), and panic attacks (15%) were also reported.

CONCLUSION

Anti-calcitonin gene-related peptide antibodies seems to significantly impact brain functions of migraineurs, preventing not only migraine headache but also its anticipatory and accompanying symptoms.

Predictors of Sustained Response and Effects of Anti-CGRP Antibodies Discontinuation and Reinitiation in Resistant Chronic Migraine

BACKGROUND

Guidelines for migraine prophylaxis suggest stopping medication after 6-12 months to reevaluate treatment appropriateness. The Italian Medicines Agency (AIFA) set a mandatory regulation to stop anti-CGRP (calcitonin gene related protein) pathway monoclonal antibody (anti-CGRP mAbs) treatments for 3 months after 12-months of treatment. Herein, we assess the effects of discontinuation and retreatment of anti-CGRP mAbs in resistant chronic migraine patients, evaluating predictive factors of sustained response.

METHODS

A monocentric prospective cohort study, enrolling 44 severe (resistant to ≥3 preventive treatments) chronic migraine patients (all with medication-overuse), treated with erenumab (54.5%) or galcanezumab (45.5%) for 12-months, who discontinued treatment for three months and then restarted for one month.

RESULTS

Overall, patients reported an increasing deteriorating trend during the three months of discontinuation. Monthly migraine days (MMDs), number of analgesics, days with at least one analgesic used, a ≥50% response rate (reduction in MMDs), and MIDAS and HIT-6 total scores, remained lower than baseline values, but increased if compared to month-12 of treatment. All outcome measures decreased again during the month of retreatment. Patients who did not meet criteria for restarting treatment had lower MIDAS (p=0.03) and HIT-6 (p=0.01) scores at baseline and better outcome measures during discontinuation compared to patients who restarted treatment.

CONCLUSIONS

In most patients, the 3-month discontinuation of anti-CGRP mAbs resulted in progressive migraine deterioration that was rapidly reverted by retreatment. However, one-fourth of patients, who reported better quality of life indices before treatment, showed a sustained benefit during discontinuation and did not need retreatment.

Long-Term Effectiveness of Three Anti-CGRP Monoclonal Antibodies in Resistant Chronic Migraine Patients Based on the MIDAS score

BACKGROUND

Criteria, including clinical features and effective outcomes, for access and persistence of novel but costly treatments may vary between countries, thus affecting the health of patients. Monoclonal antibodies against the calcitonin gene-related peptide pathway (anti-CGRP mAbs) for migraine treatment are currently prescribed following strict criteria.

OBJECTIVE

The aim was to assess the effectiveness and safety of three anti-CGRP mAbs (erenumab, galcanezumab, and fremanezumab) in consecutive resistant chronic migraine patients presenting at our Headache Center and the impact of criteria set by the Italian Medicines Agency to start and continue (achieving a ≥ 50% reduction in Migraine Disability Assessment [MIDAS] score) with treatment under the reimbursement program.

METHODS

A monocentric, prospective, cohort study was conducted, enrolling 203 severe (resistant to three or more preventive treatments) chronic migraine patients (84.7% with medication overuse) treated with erenumab (47.2%), galcanezumab (36.5%), or fremanezumab (16.3%), with up to 12 months follow-up. Patients completed a headache diary that included monthly migraine days (MMDs), number of analgesics and days with analgesic use, and patient-reported outcome questionnaires (MIDAS, Headache Impact Test 6 [HIT-6] questionnaires, and the Patient Global Impression of Change [PGIC] scale). Moreover, percentages of patients showing ≥ 50%, ≥ 75% and 100% reduction in MMDs (responder rates) were calculated at different follow-ups. A subgroup analysis was performed for patients with 12-month follow-up. Potential predictors of response were assessed at different follow-ups.

RESULTS

In the overall population, all three anti-CGRP mAbs were similarly effective and dropouts were 17.2%. The percentage of patients with ≥ 50% reduction in MMDs (min-max 36.4-56.8%) and in monthly analgesic consumption (51.1-75.7%) was inferior to the percentage of patients who reported a ≥ 50% reduction in MIDAS score (89.5-100%). HIT-6 score was also consistently reduced at all follow-ups. In patients with a 12-month follow-up, MIDAS and HIT-6 scores were also reduced at all follow-ups compared with baseline, with 84.4-100% of patients achieving a ≥ 50% reduction in MIDAS score, and patients with a ≥ 50% response rate ranging from 36.4 to 66.6%. No severe adverse events were recorded. Fewer migraine days at baseline were associated with ≥ 50% response rate at 1 month and fewer MMDs, years of chronic migraine, and monthly analgesic use at 6 months.

CONCLUSION

In resistant chronic migraine patients, anti-CGRP mAbs are effective and safe. A ≥ 50% reduction in MIDAS score seems to be the most advantageous outcome measure in this setting, which allows most severe migraine patients to persist with treatment.

Galcanezumab effectiveness on comorbid cluster headache and chronic migraine: a prospective case series

BACKGROUND

Cluster headache (CH) and migraine are recurrent painful primary cephalalgies, typically with different clinical appearance and some shared features, such as unilateral pain, common triggers and response to triptans and/or monoclonal antibodies against the calcitonin gene-related peptide (CGRP) pathway. Common pathophysiological mechanisms are proposed in CH and migraine, including the role of the trigeminal-vascular system with its most representative neuropeptide, CGRP. Very few case series have been conducted so far investigating anti-CGRP treatments in patients with comorbid CH and migraine, and no cases have been reported which assess both CH and chronic migraine outcomes.

CASE SERIES

We describe 4 patients with both chronic migraine and cluster headache, with or without failure to preventive medications. Galcanezumab (240 mg loading dose, followed by 120 mg monthly) was used for at least a 3-month treatment, demonstrating improvement in both migraine and CH outcomes (i.e. migraine days, CH attacks, Headache Impact Test -6 item score, acute medications use), achieving sustained clinical benefit. No adverse events were reported.

DISCUSSION AND CONCLUSION

Taking into account the role of CGRP in migraine and CH pathophysiology, a usually well-tolerated treatment with CGRP blockade could be a rationale-based option to treat patients with coexisting chronic migraine and cluster headache. Additional studies are needed to assess the role of anti-CGRP drugs in episodic and chronic CH treatment, as well as to establish correct timing and patient prerequisites to begin therapy.

Novel Mixed NOP/Opioid Receptor Peptide Agonists

The nociceptin/orphanin FQ (N/OFQ)/N/OFQ receptor (NOP) system controls different biological functions including pain and cough reflex. Mixed NOP/opioid receptor agonists elicit similar effects to strong opioids but with reduced side effects. In this work, 31 peptides with the general sequence [Tyr/Dmt¹,Xaa⁵]N/OFQ(1-13)-NH₂ were synthesized and pharmacologically characterized for their action at human recombinant NOP/opioid receptors. The best results in terms of NOP versus mu opioid receptor potency were obtained by substituting both Tyr¹ and Thr⁵ at the N-terminal portion of N/OFQ(1-13)-NH₂ with the noncanonical amino acid Dmt. [Dmt^1,5]N/OFQ(1-13)-NH₂ has been identified as the most potent dual NOP/mu receptor peptide agonist so far described. Experimental data have been complemented by in silico studies to shed light on the molecular mechanisms by which the peptide binds the active form of the mu receptor. Finally, the compound exerted antitussive effects in an in vivo model of cough.

[The Paduan doctor Alessandro Pellati, his library and the first edition of De medicorum astrologia]

The article prints the text of a document in the Archivio di Stato, Venice, comprising a list of books intended for auction, with an estimate of their value. THey constitute the private library of Alessandro Pellati (d. 1487), a Paduan doctor about whom nothing is known, except his name appears in the colophon of the first edition of a short treatise attributed to Hippocrates, the De medicorum astrologia seu de esse aegrorum, translated into Latin and published in Padua in 1483. The considerable number of astrological works in his library show that Pellati was keenly interested in the subject which, under the title of "natural magic", had assumed a significant place in medical studies at that time, particularly in Padua.

A new method for chemoselective conjugation of unprotected peptides to dauno- and doxorubicin

A new approach for chemoselective ligation of peptides to dauno- and doxorubicin through an oxime bond is presented. The method does not require protecting groups on the peptide moiety.

Role of charged residues in the catalytic mechanism of hepatitis C virus NS3 protease: electrostatic precollision guidance and transition-state stabilization

Maturational cleavage of the hepatitis C virus polyprotein involves the viral chymotrypsin-like serine protease NS3. The substrate binding site of this enzyme is unusually flat and featureless. We here show that NS3 has a highly asymmetric charge distribution that is characterized by strong positive potentials in the vicinity of its active site and in the S5/S6 region. Using electrostatic potential calculations, we identified determinants of this positive potential, and the role of six different residues was explored by site-directed mutagenesis. Mutation of residues in the vicinity of the active site led to changes in k(cat) values of a peptide substrate indicating that basic amino acids play a role in the stabilization of the transition state. Charge neutralization in the S5/S6 region increased the K(m) values of peptide substrates in a manner that depended on the presence of negatively charged residues in the P5 and P6 positions. K(i) values of hexapeptide acids spanning P6-P1 (product inhibitors) were affected by charge neutralization in both the active site region and the S5/S6 region. Pre-steady-state kinetic data showed that the electrostatic surface potential is used by this enzyme to enhance collision rates between peptidic ligands and the active site. Calculations of the interaction energies of protease-substrate or protease-inhibitor complexes showed that electrostatic interaction energies oppose the formation of a tightly bound complex due to an unfavorable change in the desolvation energy. We propose that desolvation costs are minimized by avoiding the formation of individual ion pair interactions through the use of clusters of positively charged residues in the generation of local electrostatic potentials.

Probing the active site of the hepatitis C virus serine protease by fluorescence resonance energy transfer

A serine protease domain contained within the viral NS3 protein is a key player in the maturational processing of the hepatitis C virus polyprotein and a prime target for the development of antiviral drugs. In the present work, we describe a dansylated hexapeptide inhibitor of this enzyme. Active site occupancy by this compound could be monitored following fluorescence resonance energy transfer between the dansyl fluorophore and protein tryptophan residues and could be used to 1) unambiguously assess active site binding of NS3 protease inhibitors, 2) directly determine equilibrium and pre-steady-state parameters of enzyme-inhibitor complex formation, and 3) dissect, using site-directed mutagenesis, the contribution of single residues of NS3 to inhibitor binding in direct binding assays. The assay was also used to characterize the inhibition of the NS3 protease by its cleavage products. We show that enzyme-product inhibitor complex formation depends on the presence of an NS4A cofactor peptide. Equilibrium and pre-steady-state data support an ordered mechanism of ternary (enzyme-inhibitor-cofactor) complex formation, requiring cofactor complexation prior to inhibitor binding.

Alpha-ketoacids are potent slow binding inhibitors of the hepatitis C virus NS3 protease

The replication of the hepatitis C virus (HCV), an important human pathogen, crucially depends on the proteolytic maturation of a large viral polyprotein precursor. The viral nonstructural protein 3 (NS3) harbors a serine protease domain that plays a pivotal role in this process, being responsible for four out of the five cleavage events that occur in the nonstructural region of the HCV polyprotein. We here show that hexapeptide, tetrapeptide, and tripeptide alpha-ketoacids are potent, slow binding inhibitors of this enzyme. Their mechanism of inhibition involves the rapid formation of a noncovalent collision complex in a diffusion-limited, electrostatically driven association reaction followed by a slow isomerization step resulting in a very tight complex. pH dependence experiments point to the protonated catalytic His 57 as an important determinant for formation of the collision complex. K(i) values of the collision complexes vary between 3 nM and 18.5 microM and largely depend on contacts made by the peptide moiety of the inhibitors. Site-directed mutagenesis indicates that Lys 136 selectively participates in stabilization of the tight complex but not of the collision complex. A significant solvent isotope effect on the isomerization rate constant is suggestive of a chemical step being rate limiting for tight complex formation. The potency of these compounds is dominated by their slow dissociation rate constants, leading to complex half-lives of 11-48 h and overall K(i) values between 10 pM and 67 nM. The rate constants describing the formation and the dissociation of the tight complex are relatively independent of the peptide moiety and appear to predominantly reflect the intrinsic chemical reactivity of the ketoacid function.

Angiotensin converting enzyme inhibitor-induced angioedema: a report of two cases

Angioedema is a rare but potentially fatal side effect of angiotensin converting enzyme (ACE) inhibitors. We report for the first time, two children with systemic lupus erythematosus who developed acute angioedema after the long-term use of enalapril. Prompt recognition and appropriate management of ACE-induced angioedema prevented life-threatening complications. This report highlights the potential risks of angioedema associated with the use of ACE inhibitors in children. Patients should be advised to seek medical treatment immediately if they experience swelling of the face, neck, or tongue, and especially if they have trouble breathing, speaking, or swallowing.