CIDP in 2026: 7 Real Updates on Diagnosis and Treatment (and What Is Still Hype)

Chronic inflammatory demyelinating polyneuropathy, almost always shortened to CIDP, is a rare condition in which the immune system damages the nerves. It causes progressive and relapsing weakness and loss of feeling. It is the long-lasting counterpart of Guillain-Barré syndrome, which comes on suddenly. Unlike most neuropathy, CIDP is treated with drugs that act on the immune system, which makes the research very different from the rest of this site.

This page lists seven updates from 2026, in order of how useful each is to you. For every item we give the date, where it was published, who was studied and what it means in practice. CIDP is serious and needs a neurologist: if weakness or numbness is getting worse, do not wait. This page cannot diagnose you. It is a companion to our guide to peripheral neuropathy.

1. How Accurate Are the CIDP Diagnostic Criteria? A 2026 Study Put Them to the Test

Status: practical now; shapes what testing to ask for. Published August 2026 in the European Journal of Neurology. Tested in people.

CIDP is diagnosed from symptoms and nerve conduction studies, since no single blood test confirms it. Researchers compared two sets of European criteria in 339 patients with CIDP and 339 matched patients who had suspected immune-related neuropathy but received a different diagnosis. The older 2010 criteria had a sensitivity of 92% when “possible” CIDP was included (91% for probable or definite) and a specificity of 67% (78%). The revised 2021 criteria had a sensitivity of 94% (83%) and a specificity of 66% (86%). When only probable or definite CIDP was counted, the 2021 version missed more real cases (sensitivity 83% against 91%) but was less likely to label other conditions as CIDP (specificity 86% against 78%).

The authors also found that testing only one side of the body would have missed 77 possible CIDP diagnoses.

What it means for you: no criteria are perfect, and a diagnosis can be wrong in both directions. If CIDP is suspected, ask whether nerve conduction studies covered both sides and several nerves. If the diagnosis feels uncertain, a second opinion at a center that treats neuromuscular disease is reasonable.

2. Efgartigimod Is Approved for CIDP, With Long-Term Safety Data From the ADHERE+ Extension

Status: available now, as a prescription option. Extension results published September 2026 in the Journal of the Peripheral Nervous System; review published October 15, 2026 in the Journal of the Neurological Sciences. Tested in people.

Efgartigimod blocks the neonatal Fc receptor (FcRn), which lowers circulating IgG antibodies, and a 2026 review describes it as now approved for CIDP. The ADHERE+ extension followed people who had taken part in the main trial and received weekly subcutaneous efgartigimod (1,000 mg). At the interim cut-off, 228 of 229 eligible patients had moved on to the extension. Treatment lasted on average 58 weeks and up to 187 weeks. Side effects were common (75.0% of patients) but mostly not severe: 18.0% had a grade 3 or worse event, and infections were low.

Among patients who had responded earlier, a disability score improved by 1.2 points, a daily-function score rose by 8.8 points and grip strength increased by 17.5 kPa by week 36 of the extension. Two caveats matter. The extension was open-label, with no placebo group, so everyone knew they were on the drug. And these figures are an interim analysis in people who had responded.

What it means for you: for people who do not respond to, or cannot use, standard treatments, this is a real new option, with more safety data than a year ago. It is a decision for your neurologist, with the cost considerations in item 4.

3. A 2026 Analysis Compared CIDP Treatments Side by Side, With Caveats

Status: information for the conversation with your doctor. Published 2026 in Frontiers in Immunology. A network meta-analysis of randomized trials.

The analysis pooled 18 randomized trials with 2,184 patients, searched through February 2026, and compared plasma exchange, corticosteroids, immunoglobulin (IVIG or subcutaneous), rituximab and the FcRn inhibitors efgartigimod and rozanolixizumab. For short-term clinical response, plasma exchange (odds ratio 33.6) and corticosteroids (15.4) had the highest probability of working. Efgartigimod also showed a significant response (3.1) and ranked highest for grip strength. Serious side effects with the FcRn drugs were comparable to placebo. The authors say IVIG remains a broadly supported comparator in both starting and maintenance treatment.

These are indirect comparisons across different trials, and the plasma exchange estimate has a very wide margin of error (confidence interval 3.2 to 358.9). The authors state the findings should inform, not replace, individual decisions.

What it means for you: a higher rank does not mean a better drug for you. Treatment choice depends on how you responded before, your other health conditions, practical limits such as access to infusion centers, and cost.

4. A Cost Model Found Immunoglobulin Cheaper Per Responder Than Efgartigimod

Status: a model, not a trial; cost depends on your insurance. Published in the December 2026 issue of the Journal of Medical Economics. An economic model from a U.S. payer perspective.

Researchers modeled the cost of an IVIG product at two maintenance doses against subcutaneous efgartigimod, using results from two separate trials (ProCID and ADHERE). Over 12 months, total treatment cost came to $190,026 for IVIG at 1 g/kg, $402,301 at 2 g/kg and $698,583 for efgartigimod. Modeled response rates at 12 months were 74%, 85% and 48%. The cost per responder was $256,792, $473,295 and $1,455,382.

The authors stress that no head-to-head trial exists, and that differences in trial design and how a “responder” was defined could affect the comparison. We could not see in the abstract who funded the study, so treat the numbers as one model’s estimate, not a verdict.

What it means for you: what you pay depends on your plan, not on list prices. Ask your neurologist’s office to check coverage and prior-authorization rules before a treatment decision, and ask the infusion center or specialty pharmacy about patient-assistance programs.

5. Switching From IVIG to Subcutaneous Immunoglobulin Often Fell Short at the Same Dose

Status: doctor-led; never switch on your own. Published September 2026 in the Journal of the Peripheral Nervous System. A small case series in people.

Subcutaneous immunoglobulin (SCIG) is given as an injection under the skin and can be more convenient than IV infusions. The current guideline considers a switch at an equivalent dose reasonable. Dutch researchers reviewed 10 stable patients switched at 1:1. Only one remained stable. Nine deteriorated within four months, three of whom recovered after the dose was raised to 1:1.3 or 1:1.5, and three did not regain stability even then. Five patients went back to IVIG. The one patient on a low dose (0.4 g/kg every 3 weeks) stayed stable, while those on 1 g/kg or more every 3 weeks deteriorated.

With only 10 people in a retrospective review, this raises a question rather than answering it, and the authors say the best dosing strategy is not yet known.

What it means for you: if you and your doctor plan a switch, ask how strength and function will be monitored in the first months and what the plan is if you slip. Monitoring after the switch matters as much as the starting dose.

6. Adding a Steroid to IVIG Was Stopped for Safety in a Randomized Trial

Status: not a proven add-on. Published May 14, 2026 in the Journal of Neurology, Neurosurgery & Psychiatry. A randomized, double-blind trial.

This trial tested whether adding high-dose intravenous steroids to IVIG raises the chance of remission. Adults with CIDP received IVIG plus either methylprednisolone (1,000 mg every 3 weeks for 18 weeks) or placebo. Enrolment was halted after 77 of the 96 planned patients because four blood-clot events occurred in the steroid group and none in the placebo group. At 52 weeks, 38% (14 of 37) of the steroid group and 28% (11 of 40) of the placebo group were in remission, a difference that was not statistically significant. Some secondary measures of disability favored the steroid group.

What it means for you: more treatment is not automatically better. If your neurologist suggests combining treatments, ask about the benefits and about clot risk, and report new leg swelling, chest pain or breathlessness right away.

7. Fampridine Did Not Help Residual Disability in a Placebo-Controlled Trial

Status: not supported for CIDP. Published in the December 2026 issue of the Journal of the Peripheral Nervous System. A randomized, double-blind crossover trial.

Many people with CIDP keep some disability even on stable immunoglobulin treatment, and no medicine targets the way the damaged nerves conduct signals. Fampridine (10 mg twice daily) acts on ion channels in nerves. In this two-center trial, 28 patients took fampridine and placebo for four weeks each. There was no significant difference in walking test or hand-dexterity test results. Grip strength and a daily-function score were actually worse on fampridine, and side effects were mostly mild.

What it means for you: this negative result is useful. If you are told a pill will fix lingering weakness, ask what evidence supports it in CIDP, and talk about rehabilitation and physical therapy, which target function directly.

What Should You Ask Your Neurologist About CIDP?

1. Was my diagnosis confirmed with thorough nerve testing? Ask whether both sides and several nerves were tested.
2. Which treatments are options for me? IVIG or subcutaneous immunoglobulin, steroids, plasma exchange and efgartigimod each have evidence, with different trade-offs.
3. How will we measure whether it is working? Grip strength and daily-function scores are used in the trials.
4. What are the risks for me? Clots, infections and infusion reactions depend on your health history.
5. What will it cost, and who can help with coverage?
6. What is the plan if I get worse after a change?

You can look up any treatment in testing on ClinicalTrials.gov, the free U.S. government registry. For a general overview of how neuropathy is diagnosed, see our small fiber neuropathy update and our guide to neuropathy with no known cause.

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