the first month, additional monthly evaluations were conducted for the first 12 months followed by quarterly evaluations for the remaining 12 months.
We fully enrolled our Phase 1 trial, having dosed a total of 15 patients in the trial. The first cohort, which completed dosing in September 2014, consisted of three infants who received a dose of AVXS‑101 administered at the low dose, based on the patient’s weight, or the low-dose cohort. The second cohort, which completed dosing in December 2015, consisted of 12 infants who received the proposed therapeutic dose of AVXS‑101, or the proposed therapeutic dose-cohort.
As of August 7, 2017, all 15 patients (100%) in the trial reached 20 months of age without experiencing an “event,” described as death or at least 16 hours per day of required ventilation support for breathing for 14 consecutive days in the absence of acute reversible illness or perioperatively, in contrast to the 8% event free rate at this time point demonstrated in an independent, peer-reviewed natural history study for patients with SMA Type 1. All 15 patients experienced improvement from baseline in motor skills measured by their CHOP INTEND scores and such improvement appeared to be dose‑dependent. As of August 7, 2017, we have observed AVXS‑101 to be generally well‑tolerated.
As of August 7, 2017, all patients in the proposed therapeutic dose‑cohort were event‑free. The median age at last follow-up was 25.7 months and 30.7 months for patients in the proposed therapeutic-dose cohort and low-dose cohort, respectively. As previously reported, one patient in the low‑dose cohort, had a pulmonary event in the third quarter of 2016 at the age of 28.8 months. The patient had increased use of bi‑level positive airway pressure, or BiPAP, in advance of surgery related to hypersalivation, a condition experienced by some SMA patients; the event was determined upon independent review to represent progression of disease and not to be related to the use of AVXS‑101. This patient completed the final trial visit in September 2016 and as of that time point, BiPAP use was below the 16 hours per day usage that defines the threshold for the survival endpoint. Although the results of the Finkel 2014 Study were not pre‑specified as a comparator for our trial, we believe that this compilation of data from patients with SMA Type 1 provides a useful context to consider the results of our trial to date. This peer‑reviewed publication reported that 8% of patients with SMA Type 1 were event‑free at 20.0 months of age. The lethality of the disease is further supported by the recent NeuroNEXT Study, which indicated a median time to death or tracheostomy for ventilation support for breathing SMA Type 1 patients from birth of eight months. The following figure shows survival data of all 15 patients enrolled in the clinical trial through August 7, 2017.
The CHOP INTEND test is designed to evaluate the motor skills of patients with SMA Type 1 by testing 16 items, which measure the movement of various body segments. As of August 7, 2017, 11 of 12 patients (92%) in the proposed therapeutic dose-cohort have achieved and maintained CHOP INTEND scores of ≥40 points. Two patients who have achieved CHOP INTEND scores of at least 60 points, which is considered to be normal, achieved the