Biosergen AB: Biosergen Agrees to Accelerated Dosing Escalation in Ongoing Second Cohort of Clinical Trial

December 20, 2024 - Stockholm, Sweden - Biosergen AB ("Biosergen"), a clinical-stage biotechnology company developing therapies for life-threatening fungal infections, announces that the independent Data Safety Review Board that is monitoring the safety and efficacy of the current clinical study, has agreed to allow investigators to exceed the previously established maximum dose of 1.5 mg/kg/day in the ongoing second cohort of its clinical trial for BSG005. This decision was made following a request from the Principal Investigator, supported by compelling preliminary data, reflecting the investigator team's expectation that BSG005 will deliver even greater clinical benefits at higher doses with no severe side effects. The independent Data Safety Review Committee reviewed and approved this request.

"This request for a further dose escalation represents an unexpectedly quick acceleration in the daily dosing level at this early stage in the development of BSG005," said Tine Olesen, CEO of Biosergen. "With patients currently undergoing treatment and in urgent need of further improvements in their condition, the only appropriate course of action is to support the investigator team. We are encouraged that no severe side effects have been observed at the planned maximum dose of 1.5 mg per day, and we are excited by the investigators' eagerness to explore higher dosing levels to maximize the potential benefits for these patients."

Preliminary Data Supporting the Protocol Amendment

The decision to increase the dose was based on outcomes from the patients enrolled in the second cohort so far:

1) Patient with Mucormycosis:
This patient presented with Mucormycosis, a severe fungal infection that had spread across multiple lobes in both lungs. After reaching the planned maximum dose of 1.5 mg/kg/day, the infection had significantly decreased; however, it had not completely disappeared.

The absence of severe side effects prompted investigators to request permission to further escalate the dose, aiming for a best-case scenario: potential complete recovery, as seen in the first patient from cohort 1, who fully recovered from a Mucormycosis infection.

The promising results with BSG005 could potentially replace the standard-of-care for such a patient, which typically involves surgical removal of large portions of the lungs. In this particular case, surgery would not have been a viable option, as removing extensive areas of affected lung tissue in both lungs would have made post-surgery survival unlikely.

2) Patient with Aspergillosis:
A second patient with a severe invasive Aspergillus infection showed significant improvement at 1.5 mg/kg/day. Investigators believe that further dose increases could enhance this patient's potential for complete recovery.

3) Patient Withdrawal:
A third patient opted to leave the trial due to experiencing shortness of breath (dyspnea) and a drop in blood pressure during dosing. While these events were not classified as severe side effects, the patient independently chose to discontinue participation.

4) Patient with Aspergillosis:

A fourth patient was included based on failure of first line therapy. He was diagnosed with Aspergillus infection and was dosed first time 19 December without any severe side effects.

Dr. Pawan Kumar Singh, an associate professor specializing in pulmonary medicine, thoracic oncology, and critical care, and the trial's principal investigator remarked:
"The positive impact we have witnessed of BSG005 on several patients in this trial is extraordinary. We are pleased that we can escalate beyond the prior dose limit for the three patients, as well as the remaining one patient yet to be enrolled in this cohort, as I believe it will strongly impact their chance of reaching a state where they can go on with their lives free from major complications of their infections."

The increased dosing levels are unexpected, and it is due to a favorable tolerability profile.  It is anticipated to result in a higher volume of BSG005 being consumed during the study than planned. Furthermore, the adjustment is likely to lead to higher maintenance doses in the planned third dose-escalation cohort, significantly increasing the total quantity of BSG005 needed and may result in an insufficient stock of BSG005 to complete the study as scheduled. Biosergen is currently evaluating the best way forward.

By virtue of the efficacy of BSG005 we have seen in already treated patients the possible delay in dosing the last patient is not expected to jeopardize the plan for the following phase 2/3 studies earlier communicated.