Disease-Modifying Therapies for MS: What They Do, and What They Don’t

Disease-modifying therapies for MS: what they do, and what they don’t

The single most consequential decision in multiple sclerosis is made in the first year or two after diagnosis, usually by someone who has just received frightening news and has very little idea what the options mean.

That decision is which disease-modifying therapy to start, and how aggressive to be. It is consequential because the evidence increasingly says that damage prevented early cannot be recovered later — and because the window in which treatment works best is the window in which people feel most well and are least motivated to take a drug with side effects.

62% of Australians with MS — 23,217 people — were on a disease-modifying therapy in 2024, according to MS Australia’s prevalence and economic report, up 35% since 2010. Those medicines cost $592 million a year, or $15,671 per person — the second-largest single component of MS’s $3 billion annual cost to Australia.

This guide explains what that money buys, what it does not buy, and the Australian access questions that have been live through 2026. It is not a recommendation of any particular drug; that is a conversation with a neurologist who has seen your MRI.

What a DMT actually does

The clearest way to understand disease-modifying therapy is to separate the two processes going on in MS.

Inflammatory activity produces relapses and new lesions. It is immune-driven, episodic, visible on MRI, and it is what DMTs are good at suppressing.

Neurodegeneration is the slow loss of axons and brain volume that drives progressive disability. It happens from early in the disease, continues between relapses, and correlates far better with long-term outcomes than relapse counts do. DMTs affect it much less.

So a DMT does three things, with decreasing confidence:

1. Reduces relapse frequency. Well established, and the headline figure in every trial.
2. Reduces new lesion formation on MRI. Well established.
3. Slows disability progression. Established for the more effective drugs over trial timeframes, and this is the outcome that actually matters.

And here is what a DMT does not do, which is the part that gets lost:

It does not repair existing damage. Function already lost does not come back because you started a DMT.

It does not treat symptoms. Fatigue, spasticity, bladder dysfunction, pain, cognitive change — none of these improve because of a DMT. They need their own management, and a person can be on a highly effective DMT with no new lesions for five years and still be severely limited by fatigue. This confuses families constantly: “the MS is under control, why is she not better?”

It does not help much in progressive MS without inflammatory activity. Options for non-active progressive disease remain limited, and this is the biggest unmet need in MS medicine.

That distinction — disease control versus symptom control — is also legally important in Australia, and we come back to it under the NDIS section.

The landscape, roughly grouped

There are now more than a dozen DMTs available in Australia. Neurologists tend to think of them in efficacy tiers, and the tiers matter more than the individual names.

Moderate-efficacy, generally safer, often oral or injected at home. Interferon beta and glatiramer acetate are the oldest, with decades of safety data and relapse reductions around a third. Teriflunomide and dimethyl fumarate are oral options in a similar efficacy range. These are the traditional “start here and escalate if needed” drugs.

High-efficacy. Natalizumab (infusion), the anti-CD20 antibodies ocrelizumab (infusion) and ofatumumab (self-injected at home), cladribine (short oral courses), alemtuzumab (two annual courses), and the S1P modulators such as fingolimod and siponimod. Relapse reductions substantially greater than the moderate tier, with more monitoring and more serious potential risks — progressive multifocal leukoencephalopathy with natalizumab in JC-virus-positive people, infection risk and hypogammaglobulinaemia with anti-CD20 therapies, secondary autoimmunity with alemtuzumab.

Autologous haematopoietic stem cell transplantation (AHSCT). Not a drug but a procedure: chemotherapy to ablate the immune system followed by reinfusion of the person’s own stem cells. In carefully selected people — younger, relapsing, highly active disease, short duration, failed other therapy — the results can be dramatic. It carries real mortality risk and is available in Australia at a small number of centres, mostly through trials and specialist referral. It is not a treatment for progressive MS without inflammatory activity, which is what most people asking about it have. Be very wary of overseas clinics selling it.

For progressive MS specifically, ocrelizumab has an indication in primary progressive MS and siponimod in active secondary progressive MS. The benefits are real but considerably more modest than in relapsing disease.

The early high-efficacy argument

This is the live debate and the thing worth understanding before your treatment conversation.

The traditional approach was escalation: start with a safer, moderately effective drug, monitor, and move up if there are relapses or new lesions. The logic is to avoid exposing people to serious risks they may not need.

The newer approach is early high-efficacy treatment: start with one of the more effective drugs straight away.

The argument for it rests on three observations. Neurodegeneration begins early, so time spent on a less effective drug is time accumulating damage. Damage is not recoverable, so there is no catching up later. And people treated early with high-efficacy therapy in observational cohorts appear to do better on long-term disability measures than those escalated.

Evidence in treatment-naive people with relapsing-remitting MS has been accumulating in this direction, and most Australian MS specialists have shifted at least partly toward it, particularly for people with active disease, poor prognostic markers on MRI — high lesion load, spinal cord lesions, posterior fossa lesions, four or more paramagnetic rim lesions — or incomplete recovery from a first relapse.

The honest counter-argument: the high-efficacy drugs carry greater risks, some people have genuinely mild disease and would have done well on anything, and the long-term safety data for the newest agents is still accumulating.

What this means practically. If you are newly diagnosed, these are reasonable questions to ask your neurologist: What is my prognosis based on my MRI? Are you recommending escalation or early high-efficacy, and why in my case? What would make you change the drug? What monitoring does this involve? And — the question people forget — what are my plans around pregnancy, because that shapes the choice substantially.

Pregnancy, which matters for most people with MS

About three in four Australians diagnosed with MS are women, and the average age at diagnosis is 20 to 40. So pregnancy is not a niche consideration; it is central.

The facts that reassure: MS does not reduce fertility, pregnancy does not worsen long-term MS outcomes, relapse rates typically fall during pregnancy — especially in the third trimester — and rise in the first three to six months postpartum. MS is not a reason to avoid pregnancy, and it is not an indication for caesarean section or against epidural anaesthesia.

The complication is that DMTs differ enormously in pregnancy compatibility. Some must be stopped well in advance with a washout period, some are considered compatible with conception or continuation, and some have specific risks. Breastfeeding compatibility differs again.

The practical point: raise pregnancy planning before choosing a DMT, not after. Switching drugs to conceive can mean a period of disease activity at exactly the wrong time, and some of the sequencing problems are avoidable with foresight. This is a conversation for a neurologist with MS expertise, ideally with input from an obstetric medicine service.

Australian access: the PBS, and the 2026 review

Australians with MS get their DMTs through the Pharmaceutical Benefits Scheme, which means they pay a co-payment rather than the real price. Given the real price — $15,671 per person per year on average — that subsidy is the difference between treatment and no treatment for most people.

PBS listing comes with authority criteria: conditions on who can be prescribed what, often requiring a confirmed diagnosis, evidence of relapses or MRI activity, and sometimes documented failure of another therapy. Your neurologist navigates this, but it is worth knowing that criteria rather than clinical judgment alone can determine what you can access, and that criteria change.

What happened in 2026

Through 2026 there was a live question over two of the most widely used MS therapies in Australia.

Ocrevus (ocrelizumab) and Kesimpta (ofatumumab) — both anti-CD20 therapies, both high-efficacy, both heavily used — came under a Pharmaceutical Benefits Advisory Committee review as part of a broader examination of MS medicine use. MS Australia ran a public campaign warning that PBS access to two vital MS treatments was under threat, and people on those drugs faced real uncertainty about whether their treatment would remain subsidised.

On 16 July 2026, the Health Minister announced that both medicines would remain on the PBS. MS Australia welcomed both the decision and a continuing PBAC review examining how the drugs are used and whether the listings remain consistent with current evidence — which, as at late October 2026, was still underway.

Two things to take from this. First, if you are on either medicine, the listing was retained. Second, PBS listings for MS therapies are not permanent fixtures, and the review process continues. It is worth being on your state MS organisation’s mailing list for exactly this reason.

Why the NDIS does not fund your DMT, and why that is fine

A question that comes up constantly, and the answer has a logic worth understanding.

The NDIS does not fund disease-modifying therapies, or any treatment for the health condition itself. That sits with the health system — the PBS, Medicare, public hospitals. The NDIS funds supports related to the functional impact of disability: personal care, therapy aimed at function, equipment, home modifications, support coordination, community participation.

So the division is: the health system treats the MS, the NDIS supports the life. Infusions, neurologist appointments, MRIs and medications are health. A support worker, a shower rail, an exercise physiology program and a wheelchair are NDIS.

This is not a gap, and arguing about it wastes energy that is better spent elsewhere. There is one place where DMTs matter enormously to an NDIS application, though, and it is counterintuitive.

The DMT argument that can defeat an access request — and how to answer it

The NDIS requires an impairment that is permanent or likely to be permanent, and the operational guideline leaves open one route to refusal: permanence can be set aside where treatment that is known, available, appropriate and evidence-based would be expected to put the impairment right.

A DMT is known, available and evidence-based. So a poorly prepared MS access request leaves open an argument that treatment will fix the problem.

The answer is in the guideline itself: for degenerative conditions, the impairment counts as permanent if treatment will not cure it or come close to removing its effects. And that is precisely the case with MS. A DMT reduces relapses and new lesions. It does not repair existing axonal damage, restore lost function, or treat fatigue, spasticity, bladder dysfunction or cognitive change.

So the sentence to get into a neurologist’s letter is something like: “Disease-modifying therapy reduces the frequency of relapses and new lesion formation. It does not restore function already lost, and will not remedy Ms X’s existing walking impairment, fatigue or cognitive change, which are permanent.”

That closes the argument before it opens. MS and the NDIS covers the rest of the access strategy.

Living with a DMT

Practical things that get less attention than the efficacy data.

Monitoring is part of the deal. Most high-efficacy therapies require regular blood tests, and some need JC virus antibody testing, immunoglobulin levels or periodic MRI. Missing monitoring is how rare risks become real ones. If transport or fatigue makes pathology visits hard, that is a legitimate support need.

Infusions take a day. Ocrelizumab is a half-day to full-day infusion every six months, with pre-medication and observation. Build it into the calendar and ask whether home infusion is available in your area.

Infection risk is real and manageable. The anti-CD20 therapies in particular reduce the antibody response to infection and to vaccines. Get your vaccinations up to date, ideally before starting, and discuss timing with your neurologist — vaccine response is better if given before an infusion cycle rather than just after. Report fevers and infections rather than waiting.

Side effects often settle. Injection-site reactions, flu-like symptoms with interferons, flushing with dimethyl fumarate, infusion reactions on the first dose. Many improve over weeks or with pre-medication. Worth persisting through where safe, and worth saying clearly if they are not improving.

Adherence matters and is boring. Missed oral doses and deferred infusions reduce effectiveness in ways that do not announce themselves. For people with MS-related cognitive change, this is a genuine risk — a blister pack, phone alarms, and a support worker who checks are legitimate and useful supports. See cognitive change in MS.

Stopping is a decision, not a default. People sometimes stop DMTs after years of stability, or on reaching an age or disability level where benefit is less clear. There is genuine clinical uncertainty here and some risk of rebound disease activity with certain drugs, particularly natalizumab and the S1P modulators. It is a conversation, not something to do quietly.

What to be sceptical about

Because MS attracts more unproven treatment than almost any condition, and people are vulnerable at diagnosis.

Stem cell clinics overseas offering treatment without the rigorous selection, oncology-grade facilities and follow-up that legitimate AHSCT requires. Real AHSCT is a serious procedure with real mortality risk, performed in accredited centres on carefully chosen patients.

Diets presented as cures. Eating well is good for everyone and some dietary patterns have modest supportive evidence. No diet has been shown to stop MS.

Chronic cerebrospinal venous insufficiency (CCSVI) and venous angioplasty. This was extensively studied and does not work.

Anything described as a cure. There is no cure for MS. There are effective treatments, and there is promising research into remyelination and EBV vaccines. Anyone promising more than that is selling something.

A reasonable test: would your neurologist be able to explain why this is or is not supported? If the answer involves the medical profession suppressing it, that is informative.