Effect of antibody switch in non-responders to a CGRP receptor antibody treatment in migraine: A multi-center retrospective cohort study

BACKGROUND

Switching between antibody classes might be a treatment option in migraine patients who have not responded to one class of a CGRP-(receptor) monoclonal antibody (mAb), but there are no efficacy data so far. In this real-world analysis, we assessed the treatment response to a CGRP-mAb in patients that have previously failed the CGRP-receptor-mAb erenumab.

METHODS

We analyzed retrospective headache diary data of 78 patients with migraine who switched between CGRP-mAbs classes at four German headache centers either due to lack of efficacy or intolerable side effects. Among these, we identified 25 patients who did not respond to erenumab after three treatment cycles (defined as <30% reduction of monthly headache days) and had complete headache documentation at least one month before and during both treatments. We assessed the ≥30% responder rate at month three after switching from erenumab to a CGRP-mAb (galcanezumab or fremanezumab) (primary endpoint). Secondary endpoints included ≥50% responder rate, monthly headache days, and monthly days with acute medication use. In an exploratory subgroup analysis patients were stratified for daily and non-daily headache.

RESULTS

The switch from erenumab to a CGRP-mAb led to a ≥30% response in one-third (32%) of the patients after three treatment cycles. A ≥50% response was achieved in 12% of the patients. Monthly headache days were reduced in month three compared to baseline (20.8 ± 7.1 to 17.8 ± 9.1; p = 0.009). Stratified analysis revealed that no patient with daily headache (n = 9) responded to the treatment switch, while a 30% response was achieved by 50% of patients with non-daily headache (n = 16).

CONCLUSION

Our findings demonstrate that a relevant proportion of erenumab non-responders might benefit from a treatment switch to a CGRP-mAb. Switching seems to be a promising treatment option especially in migraine patients with non-daily headache.

Knockout of purinergic receptor Y13 (P2Y13) results in an improved outcome of metabolic syndrome in mice

 

Metabolic syndrome (MetS) clusters the main risk factors for cardiovascular diseases (CVDs) and endocrine dysfunction. The pathomechanism of MetS is described as local death of hypertrophic adipocytes releasing danger-associated molecular patterns (DAMPs) such as nucleotides (e.g. ADP). This promotes a long term inflammation of adipose tissue via activation of purinergic receptors with a gradual shift towards a pro-inflammatory environment. The ADP receptor P2Y13 is both described in metabolic and immunological processes. These combined characteristics make the P2Y13 an interesting candidate to investigate its role in MetS. Nevertheless, the role of P2Y13R in the pathogenesis of MetS is currently unknown and shall be analyzed in this study.

BMDM isolation and differentiation to Mϕ using M-CSF and subsequent stimulation with medium, LPS and IFNγ or IL4; Expression was quantified using Taqman. Male C57Bl6/J wild-type (WT) and P2Y13-deficient (KO) mice were fed a HFD for 20 weeks; body weight and food consumption were recorded weekly. GTT, ITT and metabolic cages were performed after 15 weeks with euthanization after 20 weeks. In order to distinguish the effect of hematopoetic or somatic cells, mice were lethally irradiated with 9.4Gy and reconstituted with donor bone-marrow (BM) via tail vein injection.

We observed a unique expression of P2Y13R on pro-inflammatory M1 Mϕ. After HFD feeding KO mice showed higher O2 consumption compared to WT mice (AUC of O2 consumption on 2nd day= KO:61620±2261mL/kg vs WT: 53830±916mL/kg, p&lt;0.05). Although KO mice consumed more food compared to WT littermates (KO:5.7±0.5g/d vs WT:3.1±0.1g/d, p&lt;0.0001), they showed significantly decelerated weight gain (e.g.week 15→KO:147,292±5,26% vs WT:180.8±15.9%, p&lt;0.05). Obese KO animals outperformed obese WT littermates in a peritoneal glucose tolerance test (GTT) (2h post-injection (post-i.) →KO:273.7±46.3mg/dL vs WT: 555.0±40.8mg/dL, p&lt;0.05). KO mice on HFD were protected from developing a fatty liver. HFD KO mice receiving WT BM show accelerated weight gain compared to KO mice receiving KO BM (e.g.week 10 WT in KO: 111.2±2.2% vs KO in KO: 102.2±1.2%, p&lt;0.05). In the GTT irradiated KO mice either receiving KO or WT BM are protected from HFD induced impaired glucose homeostasis (45min post-i.; KO→KO:222.1±21.2mg/dL vs WT→KO:232.8±15.9mg/dL vs WT on chow diet:240.4±18.6mg/dL). Contrary, WT mice receiving KO or WT BM developed a glucose resistance comparable to non-irradiated WT mice (45min post-i.; WT→WT:423.8±61.7mg/dL vs KO→WT:434.3±51.1 vs WT on HFD:574.4±7.9).

P2Y13 KO improves the outcome of MetS in mice with improved glucose homeostasis, decelerated weight gain, no fatty liver development and better metabolic turnover. BM transplantation experiments suggest a somatic component as possible explanation of these observations. Given these beneficial metabolic effects, we hypothesize that antagonization of P2Y13R could be a promising therapeutic tool in the field of MetS.

Funding Acknowledgement

Type of funding source: None

Deficiency of the purinergic receptor P2X4 limits atherosclerosis in mice

Introduction

Extracellular nucleotides like ATP promote inflammation as danger signals in various chronic diseases via purinergic receptors. In our previous work we identified P2X4 expression in murine atherosclerotic lesions. Therefore, we hypothesized a contribution of the ATP-P2X4 axis to vascular inflammation in atherosclerosis.

Methods

To investigate the functional role of P2X4 in atherogenesis, wild-type LDL-receptor deficient mice (LDLR−/−) and P2X4-deficient LDLR−/− mice (P2X4−/−LDLR−/−) were fed a high cholesterol diet for 16 weeks. Plaque progression in aortic arches was monitored by echography at intervals of 4 weeks, and leukocyte subsets in blood samples were analysed by flow cytometry. Atherosclerotic lesions were then assessed histologically in aortic root, arch, and abdominal aorta. In order to assess leukocyte recruitment, intravital microscopy was performed after injection of ATP in P2X4−/− or wildtype mice (WT). Regarding transferability to human disease, atherosclerotic plaque from carotid endarterectomy has been stained immunohistochemically for P2X4-receptor expression.

Results

After 16 weeks, P2X4-deficient mice showed significantly reduced atherosclerotic lesions in the aortic root (n=40, LDLR−/−: 0.47 mm2, P2X4−/−LDLR−/−: 0.39 mm2, p=0.04). Ly6C- monocyte count in peripheral blood was higher in P2X4−/−LDLR−/− (n=32, LDLR−/−: 241/μl, P2X4−/−LDLR−/−: 542/μl, p=0.0088), shifting the balance to a more anti-inflammatory subset. Memory-cell generation of CD4-T-cells is significantly higher in knockout-mice, suggesting an involvement of T-helper cells (n=25, LDLR−/−: 27%, P2X4−/−LDLR−/−: 46%, p=0.0003). Peritoneally injected ATP induced leukocyte rolling in WT, but not in P2X4-deficient mice. In human carotid arteries, atherosclerotic plaque shows higher staining for P2X4−/− receptor than not diseased areas.

Conclusion

P2X4-deficiency enhances anti-inflammatory leukocytes in peripheral blood and reduces atherosclerosis. Therefore, blocking the ATP-P2X4 axis may prevent leukocyte recruitment to atherosclerotic lesions and could present a potential new target for anti-atherogenic therapy.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported by a research grant of the German Research Foundation (DFG) to Peter Stachon. Sebastian König was supported by a research grant of the German Cardiac Society (DGK)

Effect of calcitonin gene-related peptide (-receptor) antibodies in chronic cluster headache: Results from a retrospective case series support individual treatment attempts

Objective

To assess the efficacy of monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor in chronic cluster headache (CCH) treatment under real world conditions.

Background

Calcitonin gene-related peptide has an important pathophysiological role in cluster headache. Although the randomised controlled trial with the calcitonin gene-related peptide antibody galcanezumab was negative, chronic cluster headache patients with insufficient response to other preventive treatments have been receiving individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies.

Methods

Data from 22 chronic cluster headache patients who received at least one dose of a calcitonin gene-related peptide(-receptor) antibody and recorded attack frequency in a headache diary were retrospectively collected at eight headache centres.

Results

The number of previous preventive therapies was 6.5 ± 2.4 (mean ± standard deviation, range: 2–11). The average number of attacks per week was 23.3 ± 16.4 at baseline and significantly decreased by −9.2 ± 9.7 in the first month of treatment with a calcitonin gene-related peptide(-receptor) antibody (p < 0.001). Fifty-five percent of the patients were 50% responders and 36% were 75% responders with respect to attack frequency. Significant reduction of attack frequency started at week 1 (−6.8 ± 2.8 attacks, p < 0.01). Results were corroborated by significant decreases in weekly uses of acute headache medication (−9.8 ± 7.6, p < 0.001) and pain intensity during attacks (−1.2 ± 2.0, numerical rating scale (NRS) [0–10], p < 0.01) in the first month. In months 2 (n = 14) and 3 (n = 10), reduction of attack frequency from baseline was −8.0 ± 8.4 (p = 0.004) and −9.1 ± 10.0 (p = 0.024), respectively.

Conclusion

Under real-world conditions, individual treatment with calcitonin gene-related peptide(-receptor) antibodies was effective in 55% of our chronic cluster headache patients. This finding supports individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies in chronic cluster headache patients insufficiently responding to other therapies.

Triptan efficacy does not predict onabotulinumtoxinA efficacy but improves with onabotulinumtoxinA response in chronic migraine patients

Chronic migraine (CM) is a highly disabling primary headache. Botulinum toxin (onabotulinumtoxinA) is effective for treatment of CM, with ~ 50% of patients responding after 24 weeks. A response predictor would prevent unnecessary treatments. Inhibiting calcitonin gene related peptide (CGRP) release from trigeminal nociceptive fibres is one of the modes of acting discussed for onabotulinumtoxinA in CM. Therefore, we hypothesized that the response to triptans might predict response to onabotulinumtoxinA. Contrariwise, onabotulinumtoxinA treatment might affect triptan efficacy. 49 CM patients scheduled for their first onabotulinumtoxinA treatment were included. Before (T0) and three months after (T1) onabotulinumtoxinA treatment, patients rated triptan efficacy and indicated number of headache days/month. At T1, patients additionally rated onabotulinumtoxinA efficacy. Headache days/month were on average reduced by 7.1 ± 7.0 days from T0 to T1 (p < 0.001). Triptan efficacy ratings at T0 did not predict onabotulinumtoxinA efficacy ratings at T1 (p = 0.19) or reduction of headache days (p = 0.37). However, triptan efficacy significantly improved from T0 to T1 in onabotulinumtoxinA responders (p < 0.001) but not in non-responders (p = 1.00). Triptan efficacy did not predict response to onabotulinumtoxinA in CM. However, triptan efficacy increased after successful onabotulinumtoxinA treatment. This supports the hypothesis that efficacy of acute migraine treatment with triptans improves with effective migraine prophylaxis.

The efficacy of lymphatic drainage and traditional massage in the prophylaxis of migraine: a randomized, controlled parallel group study

This study aimed at examining the efficacy of lymphatic drainage (LD) and traditional massage (TM) in the prophylactic treatment of migraine using controlled prospective randomized clinical trial of 64 patients (57 women, 45 ± 10 years) with migraine with and without aura. Patients were randomized into three groups: LD (n = 21); TM (n = 21); waiting group (WG, n = 22). After a 4-week-baseline, a treatment period of 8 weeks was applied followed by a 4-week observation period. The patients filled in a headache diary continuously; every 4 weeks they filled in the German version of the CES-D and the German version of the Headache Disability Inventory. The main outcome measure was migraine frequency per month. At the end of the observation period, the number of migraine attacks and days decreased in the LD group by 1.8 and 3.1, respectively, in the TM group by 1.3 and 2.4, and in the WG by 0.4 and 0.2, respectively. The differences between LD and WG were significant (p = 0.006 and p = 0.015, respectively) as well as the differences between TM und WG (p = 0.042 and p = 0.016, respectively). There was a significant decrease in the amount of analgesic intake in the LD group compared to the two other groups (p = 0.004). TM and LD resulted in a reduction of migraine attack frequency. The analgesic intake only decreased significantly during LD intervention. Useful effects were identified for LD and TM as compared to WG for the prophylaxis of migraine. LD was more efficacious in some parameters than TM.

Entwicklung eines Migräneprophylaxe-Screeninginstruments (MPS)

The aim of the present study was to develop a screening tool to aid non-headache specialists, like general practitioners, in deciding whether migraine prophylaxis in the individual migraine patient is useful or not. The first step was the development of a questionnaire, consisting of 10 items, which was filled in by 132 migraineurs who called on neurologists or headache experts. Independently, the physicians filled in another questionnaire to answer the question of whether they decided to prescribe migraine prophylaxis and if they had, to give their reasons for doing so. Using logistic regression analysis, we identified the three questions which had the most influence on the decision regarding prophylaxis in the data set. As results, we identified the following three questions: 1. Do you suffer from migraine on more than 3 days/month? 2. Do you have to rest in bed while experiencing a migraine attack? 3. Do you have to take medication against migraine on more than 5 days/month? Validation of this reduced questionnaire is currently ongoing and involves 150 migraine patients of general practitioners.

Sumatriptan nasal spray: a dose-ranging study in the acute treatment of migraine

This multicentre, randomized, double-blind, placebo-controlled, parallel group dose-ranging study compared the efficacy and tolerability of four doses of sumatriptan nasal spray (2.5, 5, 10 and 20 mg) with a placebo, in the acute treatment of a single migraine attack. In total, 544 patients received the study medication as a single spray in one nostril, to treat a single migraine attack in the clinic. Efficacy assessments included the measurement of headache severity, clinical disability, and the presence/absence of associated symptoms. The incidence of headache recurrence was also assessed. The three highest doses of sumatriptan (5 mg 49%, 10 mg 46%, 20 mg 64%) were significantly better than the placebo (25%) at providing headache relief (moderate or severe headache improving to mild or none) 120 min after treatment (P </= 0. 01). Also, the 20 mg dose was significantly superior to both the 10 and 5 mg doses at this time point (P < 0.05). The proportion of patients who were headache-free 120 min after treatment, was also higher following 20 mg (42%) rather than following any other sumatriptan dose (14-24%, P < 0.005 20 vs 10 mg) or placebo (11%). Headache recurrence in patients who had responded to initial treatment was reported by 30-41% of patients who received sumatriptan, compared with 33% of patients in the placebo group. Sumatriptan nasal spray was well tolerated, the incidence of adverse events with each dose of sumatriptan being similar to the placebo (20-27 and 23%, respectively). Apart from bad/bitter taste, the events were comparable with those reported following sumatriptan treatment by other routes of administration.

Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study

In order to evaluate the prophylactic effect of oral magnesium, 81 patients aged 18-65 years with migraine according to the International Headache Society (IHS) criteria (mean attack frequency 3.6 per month) were examined. After a prospective baseline period of 4 weeks they received oral 600 mg (24 mmol) magnesium (trimagnesium dicitrate) daily for 12 weeks or placebo. In weeks 9-12 the attack frequency was reduced by 41.6% in the magnesium group and by 15.8% in the placebo group compared to the baseline (p < 0.05). The number of days with migraine and the drug consumption for symptomatic treatment per patient also decreased significantly in the magnesium group. Duration and intensity of the attacks and the drug consumption per attack also tended to decrease compared to placebo but failed to be significant. Adverse events were diarrhea (18.6%) and gastric irritation (4.7%). High-dose oral magnesium appears to be effective in migraine prophylaxis.

Topical 0.025% capsaicin in chronic post-herpetic neuralgia: efficacy, predictors of response and long-term course

In order to evaluate the efficacy, time-course of action and predictors of response to topical capsaicin, 39 patients with chronic post-herpetic neuralgia (PHN), median duration 24 months, were treated with 0.025% capsaicin cream for 8 weeks. During therapy the patients rated their pain on a visual analogue scale (VAS) and a verbal outcome scale. A follow-up investigation was performed 10-12 months after study onset on the patients who had improved. Nineteen patients (48.7%) substantially improved after the 8-week trial; 5 (12.8%) discontinued therapy due to side-effects such as intolerable capsaicin-induced burning sensations (4) or mastitis (1); 15 (38.5%) reported no benefit. The decrease in VAS ratings was significant after 2 weeks of continuous application. Of the responders 72.2% were still improved at the follow-up; only one-third of them had continued application irregularly. Treatment effect was not dependent on patient's age, duration or localization of PHN (trigeminal involvement was excluded), sensory disturbance or pain character. Treatment response was not correlated with the incidence, time-course or severity of capsaicin-induced burning. If confirmed in controlled trials, the long-term results of this open, non-randomized study might indicate that the analgesic effect of capsaicin in PHN is mediated by both interference with neuropeptide metabolism and morphological changes (perhaps degeneration) of nociceptive afferents.

[Systemic pharmacotherapy in backache. Indications and practical applications]

The treatment of acute and chronic low back pain is a problem frequently encountered in the doctor's office. Selective drug therapy has a useful role to play within the framework of the overall therapeutic strategy. Indications and practical application of the major analgesic agents in various low back pain conditions are discussed.