Some of the more exciting developments at this year's annual meeting of the American Society of Clinical Oncology (ASCO) which is on its last day (June 1-5) are clearly Immunotherapy treatments. I had previously mentioned the innovative developments with Anti-PD-1 (BMS-936558, MDX-1106) from Bristol-Myers Squibb Co (BMY) targeting the immune surprising capacity of tumors, an untapped area.
Further developments would include Roche-Genentech (RHHBY.PK) who shared data on the antibody conjugate T-DM1 which delayed tumor progression in metastatic breast cancer patients by an average of 3.2 months. This development is important because it allows the targeting of a drug by linking it to an antibody that carries it to the tumor, hence reducing the toxicity of the drug because less is needed to reach that target.
Also, among the exciting developments, ImmunoCellular Therapeutics (IMUC). Below I summarize some of the data I felt was most interesting with IMUC. The targeting of cancer stem cells is an untapped area which stands to make an impact in the oncology drug development marketbecause of its increasingly recognized role in resistance and recurrence in tumor biology.
Immunocellular Therapeutics ICT-107: Immunocellular Therapeutics presented their data in two presentations on June 2nd of the 2012 meeting of the American Society of Clinical Oncology on tumor antigen expression and a correlation with survival in patients with newly diagnosed glioblastoma multiform (GBM) receiving the vaccine ICT-107. The most significant part regarding the study is that they measured the tumor specific antigens targeted by ICT-107 before the patients were ever treated and most importantly, the ones associated with the presence of cancer stem cells. They then, showed that this tumor associated antigens decreased significantly after treatment with ICT-107 and that this decrease is correlated with survival.
Summarizing some of the technical details:
- In the study, 16 newly diagnosed GBM patients treated with the drug were analyzed. ICT-107 targets six tumor associated antigens including HER2, TRP-2, gp100, MAGE-1, IL13Rα2, and AIM-2. As of February 1, 2012, six of 16 GBM patients showed no evidence of tumor recurrence (44-63 months). Median progressive free survival (PFS) in newly diagnosed patients was 16.9 months with a two-year PFS rate was 43.8% (95% CI, 19.8-66.0). The median overall survival rate (OS) was 38.4 months and a two-year OS was 80.3% (95% CI, 58.6-96.7).
- Target antigens and the cancer stem cell antigens CD133 were down regulated significantly after vaccine which confirms cancer stem cells were hit in the study.
- This increased PFS and OS were observed with increased expression of the targeted tumor antigens (specifically) MAGE-1, AIM-2, gp100 and HER2 (the more the antigen was over expressed, the more impact the drug had).
What impact this data has on the product development and the success going forward is that it is positive empirical evidence that the drug is having the predicted effect of targeting important tumor associated antigens (including those on cancer stem cells) and that this targeting is associated with the benefits observed. Currently, the Phase IIb trial for ICT-107 is underway and is close to completing enrollment of patients. In another poster, ImmunoCellular Therapeutics showed a very rapid enrollment rate of 213 patients over the last 15 months. This momentum speaks volume for the level of excitement about this study as well as the unmet need being served by the drug. Prior studies for GBM have usually taken 2-3 years to enroll 200 patients. Talking to a few of the leading Neuro-oncologists confirmed that although they have several ongoing trials, they are recruiting patients more actively in this trial because of excitement around earlier phase I data. The final analysis is expected next year which could be a game changer for the glioblastoma treatment if ICT-107 continued to show long term survival benefit.
Disclosure: I am long IMUC.