CGRP antibody therapy in patients with drug resistant migraine and chronic daily headache: a real-world experience

Background Calcitonin gene-related peptide (CGRP) (receptor) antibodies (erenumab, fremanezumab and galcanezumab) are increasingly used in prophylactic treatment of migraine. In the approval studies, severely affected patients with migraine and chronic daily headache without any headache free days were excluded. Thus, less is known about the effectiveness of CGRP antibody treatment in this cohort. Methods Clinical routine data of 32 patients with migraine and daily headache were analysed after three months of treatment with a CGRP antibody (16 erenumab, 7 galcanezumab, 9 fremanezumab), including changes of monthly headache days (MHD) monthly migraine days (MMD) and monthly acute medication intake (AMD) as well as migraine characteristics. Statistical analysis was performed with the Wilcoxon-Test. Migraine characteristics were analysed descriptively. Results The number of MHD was significantly reduced (mean reduction (standard error), p-value): (-4.2 (1.3), p = 0.009) as well as MMD (-4.3 (1.6), p = 0.033). Four patients (13 %) reached a 50 % reduction regarding MHD and 8 patients (25 %) regarding MMD, migraine duration and intensity improved under therapy. Conclusions Despite the low responder rate, CGRP antibodies can be effective at least in a few cases of severely affected patients with drug resistant migraine and chronic daily headache. Trial registration Retrospective registered.

PACAP induces light aversion in mice by an inheritable mechanism independent of CGRP

The neuropeptides CGRP and PACAP have emerged as mediators of migraine, yet the potential overlap of their mechanisms remains unknown. Infusion of PACAP, like CGRP, can cause migraine in people, and both peptides share similar vasodilatory and nociceptive functions. In this study, we have used light aversion in mice as a surrogate for migraine-like photophobia to compare CGRP and PACAP and ask whether CGRP or PACAP actions were dependent on each other. Similar to CGRP, PACAP induced light aversion in outbred CD-1 mice. The light aversion was accompanied by increased resting in the dark, but not anxiety in a light-independent open field assay. Unexpectedly, about a third of the CD-1 mice did not respond to PACAP, which was not seen with CGRP. The responder and nonresponder phenotypes were stable, inheritable, and not sex-linked, although there was generally a trend for greater responses among male mice. RNA-seq analysis of trigeminal ganglia yielded hieriechial clustering of responder and nonresponder mice and revealed a number of candidate genes, including greater expression of pituitary hormones and receptors in a subset of responder mice. Importantly, an anti-PACAP monoclonal antibody could block PACAP-induced light aversion but not CGRP-induced light aversion. Conversely, an anti-CGRP antibody could not block PACAP-induced light aversion. Thus, we propose that CGRP and PACAP act by independent convergent pathways that cause a migraine-like symptom in mice.SignificanceThe relationship between the neuropeptides CGRP and PACAP in migraine is relevant given that both peptides can induce migraine in people, yet to date only drugs that target CGRP are available. Using an outbred strain of mice, we were able to show that most, but not all, mice respond to PACAP in a preclinical photophobia assay. Our finding that CGRP and PACAP monoclonal antibodies do not cross-inhibit the other peptide indicates that CGRP and PACAP actions are independent and suggests that PACAP-targeted drugs may be effective in patients who do not respond to CGRP-based therapeutics.

Impaired wound healing in a migraine patient as a possible side effect of calcitonin gene-related peptide receptor antibody treatment: A case report

Introduction Wound healing disturbances as possible side effects of calcitonin gene-related peptide (CGRP) antibody treatment have been discussed previously but not yet described in humans. Basic research suggests that calcitonin gene-related peptide plays an important role in keratinocyte migration, vascularization and immune response and lack of calcitonin gene-related peptide may lead to impaired wound healing. Case A 51-year-old female migraine patient was treated with the CGRP receptor antibody erenumab for 6 months, which led to a relevant reduction of migraine days. During the treatment, two periods of severely impaired wound healing occurred after a trivial skin injury without spatial relation to the injection site. Skin biopsy confirmed a deep perivascular and interstitial lymphohistiocytic infiltrate with admixed eosinophils, ulceration of the epithelium, a heavy edema of the papillary dermis and focally thrombosed vessels. Conclusion Impaired wound healing might be relevant side effects of CGRP antibody therapy and anamnesis within the course of treatment should also include possible observation of impaired wound healing or planned surgery.

Sustained reductions in migraine days, moderate-to-severe headache days and days with acute medication use for HFEM and CM patients taking fremanezumab: Post-hoc analyses from phase 2 trials

Background In phase 2 and 3 studies, fremanezumab, a monoclonal CGRP antibody, was an effective preventive treatment for high-frequency episodic migraine (HFEM) and chronic migraine (CM). Objective Post-hoc analyses evaluated population-wise 50%, 75% and 100% responder rates, and the extent to which individual responders sustained a 50%, 75% and 100% reduction in migraine days, moderate-to-severe (M/S) headache days and days of acute medication use during all three treatment months of the fremanezumab phase 2 studies. Design/methods HFEM patients received either placebo or three once-monthly injections of 225 mg or 675 mg. CM patients received either placebo or three once-monthly injections of 900 mg, or an initial loading dose of 675 mg and subsequent injections of 225 mg. Patients reported headache-related data daily using an electronic diary. Results In the HFEM study, the percent of patients on fremanezumab doses 225 mg and 675 mg were greater compared to the percent of placebo patients with sustained 50% reduction in migraine days (39% and 35% vs. 10% for placebo, both p < 0.0001), M/S headache days (36% and 38% vs. 16% placebo, p = 0.0017 and p = 0.0007 respectively), and acute medication use days (36% and 27% vs. 8% placebo, p < 0.0001 and p = 0.0003). Likewise, although there were fewer patients with sustained 75% reduction, there were increases in the percent of patients on fremanezumab 225 mg and 675 mg in the HFEM study relative to placebo patients in migraine days (19% and 11% vs. 3% placebo, p = 0.0002 and p = 0.0176), M/S headache days (19% and 15% vs. 2% placebo, p = 0.0001 and p = 0.0011) and days of acute medication use (16% and 8% vs. 2% placebo, p = 0.0005 and p = 0.0377). In the CM study, there were increases in the percent of patients on fremanezumab 675/225 mg and 900 mg with 50% sustained reduction in M/S headache days (32% and 40% vs. 15% placebo, p = 0.0058 and p = 0.0002) and days of acute medication use (26% and 22% vs. 11% placebo, p = 0.0098 and p = 0.0492). There were also increases in the percent of patients on fremanezumab 675/225 mg and 900 mg compared to patients on placebo with 75% sustained reduction in M/S headache days (10% and 13% vs. 3%, p = 0.0665 and p = 0.0203). Few patients had 100% sustained reductions in these parameters in either study. Conclusions Post-hoc results must be interpreted with caution; nonetheless, a statistically significant percentage of patients who initially responded to fremanezumab within 1 month sustained this response over the subsequent 2 months. Sustained reduction in individual patients may provide a novel patient-centric, clinically meaningful endpoint for future trials assessing the effectiveness of preventive migraine treatments. Trials are registered as http://clinical trials.gov as NCT02025556 and NCT02021773.