Peloton Therapeutics Announces Clinical Data Update for PT2977 at European International Kidney Cancer Symposium

Peloton Therapeutics, Inc., a clinical-stage biopharmaceutical company
advancing first-in-class oral medicines for cancer and other serious
conditions, announced today the presentation of data from the Phase 2
portion of the company’s Phase 1/2 clinical trial of its lead drug
candidate, PT2977, at the Fourteenth European International Kidney
Cancer Symposium in Dubrovnik, Croatia. In the Phase 2 portion of the
trial, highlighted in an oral presentation and poster session at the
symposium, PT2977 showed encouraging anti-tumor activity with a
favorable safety profile in patients with previously-treated advanced
renal cell carcinoma (RCC).

The presentation titled, “A First-in-Human Phase 1/2 Trial of the Oral
HIF-2α Inhibitor PT2977 in Patients with Advanced RCC,” was delivered by
lead author Toni K. Choueiri, M.D., Director of the Lank Center for
Genitourinary (GU) Oncology at Dana-Farber Cancer Institute and the
Jerome and Nancy Kohlberg Chair and Professor of Medicine at Harvard
Medical School.

PT2977 is an oral, small molecule inhibitor of hypoxia-inducible factor
(HIF)-2α, a transcription factor that is the key oncogenic driver in
RCC. Inhibiting HIF-2α can impact multiple pathways that contribute to
RCC progression.

The Phase 1/2 study evaluated the safety and efficacy of PT2977. The
Phase 1 portion included a once daily administration schedule dose
escalation cohort of 37 patients with advanced solid tumors. Based on
the results of this cohort, 120 mg once daily was selected as the
recommended Phase 2 dose (RP2D). In the Phase 2 portion, 52 patients
with advanced clear-cell RCC who had received at least one prior therapy
received PT2977 at the RP2D. The data presented included all 52 patients
from the Phase 2 portion and three RCC patients from the Phase 1 portion
treated at the RP2D, for a total of 55 patients. The data cut-off date
for the presentation was January 1, 2019.

Among the 55 patients who were treated at the RP2D, 12 patients (22%)
had a confirmed partial response. Median progression free survival (PFS)
was not yet reached in the study with a median follow-up of 9 months,
and 36% of patients remained on study at the time of the data cut-off.

PT2977 was well tolerated. The most common adverse event was anemia,
which was anticipated given regulation of erythropoietin (EPO) by
HIF-2α. Two patients discontinued treatment for drug-related adverse
events and three other patients required dose reductions for
drug-related adverse events.

“The data from this trial indicate that HIF-2α inhibition has the
potential to become a promising new treatment option for patients with
renal cancer,” said Dr. Choueiri. “The data show that PT2977 can provide
clinically meaningful responses in heavily pre-treated patients with a
favorable safety and tolerability profile.”

“We are delighted with these results,” said John A. Josey, Ph.D.,
Peloton’s Chief Executive Officer. “The data presented today pave the
way for a planned monotherapy Phase 3 trial that will further explore
this exciting new mechanism of action in patients with advanced kidney
cancer.”

Further information on the clinical trial of PT2977 can be found on clinicaltrials.gov
(Study identifier: NCT02974738). The poster and presentation slides are
available online at: https://www.pelotontherapeutics.com/publications.

About PT2977

PT2977 is a once-daily, oral inhibitor of hypoxia-inducible factor-2α
(HIF-2α). PT2977 has demonstrated anti-tumor activity with a favorable
safety profile in an early-stage clinical study in patients with solid
tumors. Peloton is also currently evaluating PT2977 in an international
Phase 2 trial in von Hippel-Lindau (VHL) disease-associated RCC.

About Peloton Therapeutics

Peloton Therapeutics, Inc. is a clinical-stage biopharmaceutical company
focused on translating novel scientific insights into first-in-class
medicines for patients with cancer and other debilitating or
life-threatening conditions. The company’s lead development program is
evaluating a small-molecule inhibitor of hypoxia-inducible factor-2α
(HIF-2α), a transcription factor implicated in the development and
progression of clear cell renal cell carcinoma and a variety of other
disorders. HIF-2α was previously thought to be intractable using small
molecules.

To learn more about Peloton Therapeutics, visit www.pelotontherapeutics.com.

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