People with early-stage rheumatoid arthritis (RA) whose disease was well controlled on methotrexate plus the biologic drug adalimumab (Humira) were, for the most part, able to maintain their progress against the disease after stopping adalimumab, according to a new study published recently in The Lancet.

Adalimumab is a type of biologic known as a tumor necrosis factor (TNF) inhibitor. Biologics used to treat RA, including TNF inhibitors, help reduce pain, stiffness and swelling by interfering with different players of the immune system, which is overactive in rheumatoid arthritis. They also slow the progression of joint damage in patients, especially when taken early in the course of the disease. Biologics can be taken along with methotrexate – a conventional disease-modifying antirheumatic drug (DMARD) that is a cornerstone of RA treatment – when the methotrexate isn’t helping enough on its own.

There are several good reasons to consider stopping biologics once they’ve done their job of putting RA into remission or minimizing disease activity. The drugs are extremely expensive, and because they suppress the immune system, they increase the risk of infections. But guidelines that spell out when it’s safe to stop a biologic without triggering a flare don’t exist. The few previous studies that looked at the question showed mixed results.

This study – a major trial conducted at 161 sites worldwide and involving more than 1,000 patients – aimed to clarify the issue. Known as the OPTIMA trial (short for Optimal Protocol for Treatment Initiation with Methotrexate and Adalimumab), it was sponsored by AbbVie, the maker of Humira.

In the first part of the study (period 1), patients who’d had active RA for about four months and had risk factors for aggressive arthritis were treated for six months with methotrexate alone or methotrexate plus adalimumab. (Some were also taking a corticosteroid, such as prednisone.) At the end of the six months, people on the combination treatment were almost twice as likely to have achieved low disease activity, defined by a 28-joint disease activity score, than people taking methotrexate alone.

All patients who achieved low disease activity moved on to period 2 of the study. Those who had been on combination therapy were randomly assigned to either stop or not stop the adalimumab for a year. Those who had been taking methotrexate alone and did well on it continued with that therapy.