New data presented at the recent American Association of Clinical Oncology (ASCO) meeting in Chicago by Abbvie, a pharmaceutical company, provides hope for those diagnosed with a glioblastoma
In November 2017, Abbvie presented results of their phase 3 clinical trial, called INTELLANCE 2, at the annual Society of Neuro-oncology meeting. This trial tested a drug called ABT-414 or Depatux-M on individuals with relapsed glioblastoma.
The drug is composed of a combination of an antibody—a type of a protein produced by the immune system—to target EGFR, a type of tumour marker, and a substance that when released inside tumour cells causes them to die.
The results of the INTELLANCE 2 trial presented in November showed that those treated with Deputax-M in combination with temozolomide (TMZ) possibly did slightly better than those treated with just TMZ alone. However, these results were not significant enough.
The most recent results, presented at ASCO, include an additional few months of data and indicate that the difference in survival between the Depatux-M and TMZ combination versus TMZ alone is greater than originally shown.
The difference between the two treatments has increased as the data ‘matures’. This means that those treated with Deputax-M and TMZ combination have shown better survival than those who were treated with TMZ alone and this difference shows up more over time.
Whilst the median overall survival shows a modest but significant increase from 8.2 months to 9.6 months, over 20% of those receiving the Deputax-M and TMZ combination survived over 2 years, compared to under 3% of those receiving just TMZ.
In addition, the Deputax-M and TMZ combination also performs very well in those individuals who have received TMZ more than 16 weeks prior to treatment. In these circumstances, median overall survival improves from approximately 10 months to 15 months.
However, because the INTELLANCE 2 trial had already been ‘unblinded’, meaning that the researchers and participants found out who took which treatment, the company cannot use these results to file for regulatory approval.
Fortunately, Abbvie are currently carrying out another clinical trial called INTELLANCE 1 that is testing Deputax-M in patients with a newly diagnosed glioblastoma. The results from this trial, if positive, can be used to file for approval from regulatory agencies.
These developments demonstrate the challenges faced by companies, as they have to balance the risk of reporting trial results too soon against the curiosity of understanding whether a treatment works.