患者の免疫機能を用いたB細胞性リンパ腫の標的治療
(Abstract #: P2)

治療がんワクチンは濾胞性リンパ腫患者の無病生存期間を有意に延長させる
Therapeutic cancer vaccine significantly prolongs disease-free survival for follicular lymphoma
8年間の無作為化コントロールphase III臨床研究の結果、患者特異的治療ワクチンBiovaxIDは濾胞性非ホジキンリンパ腫の無病生存期間を有意に延長させることが示された。この治療は患者の免疫機能を用いて従来の化学療法に対する反応を増強させるものである。第45回American Society of Clinical Oncology学会で発表されたこのスタディにおいて、PACE(プレドニゾン、ドキソルビシン、シクロフォスファミドおよびエトポシド)化学療法により完全寛解となった濾胞性リンパ腫患者177人をBiovaxIDワクチン群(ワクチンとKLH/GM-CSF)またはコントロール群(KLH/GM-CSFのみ)に無作為に割り付けた。研究者らは化学療法に対する完全寛解を6ヵ月以上維持し、実薬ワクチン(76人)またはコントロール(41人)を投与された患者117人を解析した。経過観察期間中央値56.6ヵ月後(12.6~89.3ヵ月)、無病生存期間中央値はBiovaxID群で44.2ヵ月であったのに対しコントロール群では30.6ヵ月であり(p=0.045;HR=1.6)、47%延長した。筆者らは、このワクチンは患者の免疫系を動員し腫瘍性B細胞のみを探して破壊するユニークなものであり、この方法は他のB細胞性リンパ腫の治療にも応用できる可能性があると述べている。
Full Text

An eight-year randomized, controlled phase III clinical study has shown that a patient-specific therapeutic vaccine, BiovaxID, significantly prolongs disease-free survival in follicular non-Hodgkin's lymphoma.

The study, which is being featured in ASCO's plenary session, found that patients who received the vaccine experienced a median disease-free survival of approximately 44 months compared to approximately 30 months for those who received a control vaccine - an increase of 47 percent.

BiovaxID is individually manufactured from a tissue biopsy obtained from a patient's own tumor. The vaccine targets an idiotype expressed by cancerous B cells in follicular lymphoma and spares normal, healthy B cells that do not express the tumor idiotype.

The final vaccine is administered as a subcutaneous injection along with granulocyte-monocyte colony stimulating factor (GM-CSF) and keyhole limpet hemocyanin (KLH), which together enhance the potency of the immune response induced by BiovaxID. A previous phase II study demonstrated that patients receiving the BiovaxID vaccine develop a highly specific immune response against tumor cells.

"With this vaccine, we've now moved into an era where we can safely use a patient's immune system to effectively fight follicular lymphoma and enhance the response to conventional chemotherapy," said Stephen J. Schuster, M.D., associate professor at the University of Pennsylvania School of Medicine and the study's lead author. "Because this vaccine uniquely recruits the patient's immune system to seek and destroy only tumor B cells, this approach may be applicable to the treatment of other B-cell lymphomas."

The study achieved its primary endpoint of prolonging disease-free survival in patients vaccinated with BiovaxID after achieving a complete response to chemotherapy. In the study, 177 patients with follicular lymphoma who had achieved a complete response to PACE (prednisone, doxorubicin, cyclophosphamide and etoposide) chemotherapy were randomized to the BiovaxID vaccine arm (vaccine plus KLH/GM-CSF) or to the control arm (KLH/GM-CSF alone). Investigators analyzed the cohort of 117 patients who, as per study protocol requirements, maintained a complete response to chemotherapy for at least six months and received active (76 patients) or control (41 patients) vaccine. After a median follow-up of 4.71 years (56.6 months, range: 12.6 - 89.3 months), the median disease-free survival in the BiovaxID arm was 44.2 months compared with 30.6 months in the control arm, which is a statistically significant difference.

BiovaxID demonstrated a favorable safety profile and was very well tolerated by patients. Further studies are planned to examine the role of BiovaxID in patients with other B-cell lymphomas and as maintenance therapy in patients with follicular lymphoma.