リンパ腫に対する有望な維持療法

リツキシマブを用いた維持療法は濾胞性リンパ腫の再発リスクを半減させる

Maintenance therapy with rituximab halves risk of follicular lymphoma recurrence

2010年ASCOで発表されたphase III国際PRIMAトライアルの結果、2年間のリツキシマブ維持療法により初回化学療法が奏効した濾胞性リンパ腫の再発リスクが50%減少したことが示された。このスタディにおいて、診断時にstage IIIまたはIVの濾胞性リンパ腫がリツキシマブベースの併用化学療法（寛解導入療法）により軽減または消失した患者を、維持療法としてさらに2年間のリツキシマブを投与する群（505人）と維持療法を施行しない群（観察群、513人）とに無作為に割り付けた。25ヵ月間の経過観察期間中央値の後、疾患の進行を認めたのはリツキシマブ群では18%であったのに対し観察群では34%であった。リツキシマブの有益性は患者の寛解ステージ、年齢、または前回の治療プロトコールに関係なく認められた。研究者らは、今回認められたリンパ腫再発リスク軽減に対するリツキシマブ維持療法の有益性を確認するにはより長期の患者追跡が必要であると述べている。リツキシマブ維持療法の忍容性は良好であり、最も多い副作用は感染症であった（リツキシマブ群37%に対し観察群22%）。QOLは両群間で同等であった。

The Phase III international PRIMA trial has found that two years of rituximab maintenance therapy reduced the risk of follicular lymphoma recurrence by 50 percent in patients who responded to initial chemotherapy.

"These findings provide hope for the way we manage this disease. Rituximab maintenance therapy is likely to become a new standard of care for these patients," said lead author Gilles Salles, M.D., professor of medicine at the University of Lyon. He noted that most patients with this type of lymphoma are at risk for a relapse within three to six years of their initial therapy.

In this study, patients with primarily stage III or IV follicular lymphoma whose disease was reduced or eliminated by rituximab-based combination chemotherapy (induction therapy) were randomly assigned to receive two additional years of rituximab as maintenance therapy (505 patients) or no maintenance therapy (observation group, 513 patients).

After a median follow-up time of 25 months, disease progression occurred in 18 percent of the rituximab group compared with 34 percent of the observation group. The benefits of rituximab maintenance were observed regardless of patients' stage of remission, age, or prior treatment regimen. The researchers noted that longer follow-up of the patients is needed to confirm the benefits of maintenance rituximab therapy for reducing the risk of lymphoma relapse.

Rituximab maintenance therapy was well tolerated, with the most common side effects being infections (37 percent for the rituximab group compared with 22 percent of the observation group). Quality of life was similar between the two groups.

Based on these data, the manufacturer of rituximab has applied for approval in the United States and Europe for an expanded indication for rituximab as maintenance therapy in these patients.

Disclosures: Gilles Salles, Consultant or Advisory Role, roche, Honoraria, roche, Research Funding, Genentech; John Seymour, Consultant or Advisory Role, roche, Honoraria, roche, Other Remuneration, roche, Research Funding, roche; Pierre Feugier, Consultant or Advisory Role, roche, Honoraria, roche; David Belada, Honoraria, roche, Other Remuneration, roche.

This study was presented at ASCO's 46th Annual Meeting in Chicago.
Research Funding Provided by: Roche Pharma