The drug was studied as a treatment for severely sick patients with non-Hodgkin lymphoma, and the most notable result was the number of patients who had a complete response. About a month into the trial, 60 percent of patients had no signs of cancer cells.
Also notable: only a few of the patients in the trial experienced extreme side effects. Three out of 22 patients experienced neurotoxicity, and none experienced severe cytokine release syndrome (sCRS), a more severe side effect.
This data, from the Phase 1 clinical trial of the drug, is welcome news for Juno, as the company faced huge setbacks with another drug in development last month.
Juno suspended their Phase 2 trial of immunotherapy treatment JCAR015 for leukemia in November after two patients died, apparently from side effects of their treatment. The trial was previously put on hold in July of this year following three similar patient deaths.
Following the most recent suspension, Juno’s stock plummeted 44 percent. Although the price has risen since the initial news, the company is still trading lower than ever before. Shares were down more than six percent in trading today, with the stock hovering around $19 per share. (Juno went public at $24 per share in December 2014).
Although the problematic JCAR015 trial and the more recent JCAR017 trial cannot be directly compared, JCAR017 appears to carry fewer extreme side effects.
That may be because of a key difference in their makeup. JCAR017 has a one-to-one ratio of helper and killer T cells, while JCAR015 is entirely composed of killer T cells. It is thought that killer T cells can cause extreme side effects by attacking healthy cells, instead of cancer cells.
The positive data means the clinical trial of JCAR017 will soon continue into Phase 2, moving further towards approval for use by the FDA.
While the complete responses observed in patients doesn’t mean they are fully cured, it does mean that JCAR017 was effective in finding and destroying cancer cells, and there is a good chance that patients who had a complete response will eventually go into remission.
For this patient group, that outcome is almost astonishing.
“Patients with multiply relapsed or refractory, aggressive Lymphoma have very poor prognosis overall,” Juno Chief Medical Officer Mark Gilbert said. All patients in the trial have either “multiply relapsed” lymphoma, meaning their disease has been wiped out but has returned multiple times, or “refractory” lymphoma, meaning their disease has either stayed consistent or worsened despite treatment.
“Conventional therapies are very poor at providing durable remissions to these patients,” Gilbert said, presenting the results at the American Society of Hematology conference yesterday.
JCAR017 is also being studied in a separate trial as a treatment for children and young adults with leukemia.
While the efficacy of these immunotherapy treatments seem to be increasing as time goes on, Gilbert said Juno’s priorities in the trial have taken on a new element: tolerability.
“The tolerability profile of the product must be balanced with the efficacy that is seen,” Gilbert said, meaning a patient’s comfort while on the treatment must be balanced with the treatment’s ability to destroy their cancer.
A higher tolerability would broaden the application of the drug by widening the number of people that would want to take it, Gilbert said. Higher tolerability would also make the drug more accessible, possibly by making it available as an outpatient treatment, and could also mean it can be used in conjunction with other treatments.