Rheumatoid arthritis affects people's joints
The NHS drugs advisory body is to reconsider guidance limiting use of new rheumatoid arthritis drugs.
The National Institute for Health and Clinical Excellence planned to ration patients in England, Wales and Northern Ireland to one anti-TNF drug each.
However, campaigners said it was vital for patients to be allowed to try alternative versions if the first stopped working.
Arthritis charities estimate that the drugs can benefit 40,000 people.
Anti-TNF (anti-tumour necrosis factor alpha) therapy drugs - adalimunab, etanercept, infliximab - can slow the progress of disease and help to reduce symptoms such as joint pain, swelling, mobility and fatigue.
Each drug works and is administered in slightly different ways.
However, they are all relatively expensive, costing a minimum of around £100 a week.
NICE had said giving patients two, or even three, anti-TNFs is not cost-effective and that doctors should offer patients the next drug in line - rituximab - which costs about £3,000 less per year than the cheapest anti-TNF.
However, around a quarter of patients do not gain any benefit from rituximab.
Arthritis charities said that would severely limit patients' options, with many left with no effective way of managing their condition.
Many, they warned, could face high levels of pain and possibly long-term disability.
Ailsa Bosworth, of the National Rheumatoid Arthritis Society, said: "We are delighted that NICE have listened to patients and clinicians and agreed to re-look at the evidence for the sequential use of Anti-TNF drugs.
"It is vital for people living with rheumatoid arthritis to have access to clinically proven drugs that can help to reduce the pain, fatigue and disability associated with this devastating disease.
"RA is a lifelong condition and it is likely that many people will need access to more than one Anti-TNF drug to help manage their disease."
Rachel Haynes, of the charity Arthritis Care, also welcomed the NICE review.
She said: "We hope that NICE will put the needs of people above cost and reach the right conclusion quickly.
"Not prescribing these life-transforming drugs to their full potential is like inventing the wheel but not using it because it is cheaper to walk.
"During this period of re-evaluation, primary care trusts must allow clinicians to prescribe these drugs when it is in the best interests of their patients."