10-K: Spruce Biosciences Reports Mixed Results in CAH Trials, Shifts Focus to Pediatric and Glucocorticoid-Sparing Therapies

Spruce Biosciences terminates one Phase 2b trial for classic CAH after failing to meet primary endpoints, while another trial and a pediatric study show promise, leading to a strategic shift in focus.

Summary

• Spruce Biosciences is a late-stage biopharmaceutical company focused on developing therapies for rare endocrine disorders.
• Their lead product candidate, tildacerfont, is being developed as a non-steroidal therapy for classic congenital adrenal hyperplasia (CAH).
• The company recently terminated the CAHmelia-203 trial after it failed to meet its primary efficacy endpoint, showing only a -2.6% placebo-adjusted reduction in androstenedione (A4) levels.
• Compliance with study medication and glucocorticoid was low, with approximately 50% of patients reporting 80% or greater compliance.
• The CAHmelia-204 trial, focusing on patients with controlled androgen levels, is ongoing, with topline results expected.
• A pediatric trial, CAHptain-205, showed that 73% of patients met the efficacy endpoint of A4 or glucocorticoid reduction, but the activity was less consistent than anticipated.
• Preliminary pharmacokinetic analysis suggests that tildacerfont is cleared more rapidly in children than in adult CAH patients.
• The company is also investigating tildacerfont for polycystic ovary syndrome (PCOS), with interim data from the POWER trial suggesting a reduction in dehydroepiandrosterone sulfate (DHEAS) levels.
• Spruce estimates the global market opportunity in patients with classic CAH is at least approximately $3.0 billion.
• The company has an exclusive licensing agreement with Kaken Pharmaceutical for the development and commercialization of tildacerfont in Japan, receiving an upfront payment of $15.0 million.

Sentiment

Score: 5

Explanation: The document presents a mixed picture. While there are positive aspects such as the pediatric trial results and the Kaken partnership, the failure of the CAHmelia-203 trial and the need for further dose optimization in children temper the overall outlook. The company's financial position is also a concern, requiring additional capital raises.

Positives

• The CAHptain-205 pediatric trial showed that 73% of patients met the efficacy endpoint of A4 or glucocorticoid reduction.
• Interim data from the POWER trial in PCOS suggests that tildacerfont may reduce DHEAS levels.
• The company has an exclusive licensing agreement with Kaken Pharmaceutical for the development and commercialization of tildacerfont in Japan.
• Tildacerfont has been generally well tolerated in clinical trials with no treatment-related serious adverse events reported.

Negatives

• The CAHmelia-203 trial did not meet its primary efficacy endpoint, showing only a -2.6% placebo-adjusted reduction in A4 levels.
• Compliance with study medication and glucocorticoid was low in the CAHmelia-203 trial, with approximately 50% of patients reporting 80% or greater compliance.
• The activity observed in the CAHptain-205 pediatric trial was less consistent than anticipated and without clear dose response.
• Preliminary pharmacokinetic analysis suggests that tildacerfont is cleared more rapidly in children than in adult CAH patients.

Risks

• The company is highly dependent on the success of tildacerfont, which is their only product candidate.
• Clinical trials may fail to adequately demonstrate the safety and efficacy of tildacerfont.
• Delays in clinical trials could increase costs and limit the ability to generate revenue.
• The market opportunities for tildacerfont may be smaller than anticipated.
• The company may not be successful in expanding their pipeline or identifying additional indications for tildacerfont.
• The company currently has no marketing and sales organization and has yet to commercialize a product.
• The company is highly dependent on key personnel and may not be successful in attracting and retaining qualified personnel.
• The company relies on third parties to conduct clinical trials and manufacture drug supplies, which could lead to delays or failures.
• The company may not be able to obtain and maintain sufficient intellectual property protection for tildacerfont.

Future Outlook

Assuming positive results from CAHmelia-204 and CAHptain-205, the company plans to meet with the FDA and comparable foreign regulatory authorities to outline the design of a registrational clinical program in adult and pediatric classic CAH. The company also plans to present final data from the POWER clinical trial at a future medical conference and continue to evaluate the optimal dose of tildacerfont in children, with topline results from additional dose ranging cohorts anticipated in the fourth quarter of 2024.

Management Comments

• The company believes the differentiated patient population between CAHmelia-203 and CAHmelia-204 supports their decision to continue with the CAHmelia-204 trial.
• The company is encouraged by the activity observed thus far at suboptimal doses in the Phase 2 dose-ranging study in children.
• The company plans to continue to evaluate the optimal dose of tildacerfont in children.

Industry Context

The document highlights the competitive landscape in the development of treatments for classic CAH, mentioning Neurocrine Biosciences, Crinetics Pharmaceuticals, and BridgeBio Pharma as competitors. It also notes the current standard of care involves high doses of corticosteroids, with more than two dozen companies manufacturing steroid-based products.

Comparison to Industry Standards

• Neurocrine Biosciences is developing a CRF1 receptor antagonist and has initiated Phase 3 registrational trials in adult and pediatric classic CAH, reporting topline results in 2023.
• Crinetics Pharmaceuticals, Inc. initiated a Phase 2 clinical trial in 2023 to evaluate the safety and efficacy of an oral ACTH antagonist in adults with classic CAH and plans to report initial results in the first half of 2024.
• BridgeBio Pharma, Inc. is evaluating an AAV5 gene therapy product candidate to treat classic CAH in a Phase 1/2 proof-of-concept clinical trial.
• The company's approach with tildacerfont is to reduce the need for high doses of corticosteroids, which is the current standard of care, and to provide a non-steroidal alternative.

Stakeholder Impact

• Shareholders may experience volatility in the stock price due to the mixed clinical trial results and the need for additional capital.
• Employees may be affected by the company's cost-cutting measures, including a reduction in force.
• Patients with classic CAH and PCOS may benefit from the development of tildacerfont, if approved.
• The company's suppliers and contract manufacturers may be affected by changes in the company's clinical trial plans and manufacturing needs.

Next Steps

• Continue the CAHmelia-204 trial and report topline results.
• Continue to evaluate the optimal dose of tildacerfont in children, with topline results from additional dose ranging cohorts anticipated in the fourth quarter of 2024.
• Meet with the FDA and comparable foreign regulatory authorities to outline the design of a registrational clinical program in adult and pediatric classic CAH, assuming positive results from CAHmelia-204 and CAHptain-205.
• Present the final data from the POWER clinical trial at a future medical conference.

Key Dates

Keywords

tildacerfont, congenital adrenal hyperplasia, CAH, PCOS, polycystic ovary syndrome, endocrine disorders, clinical trials, androstenedione, A4, glucocorticoids, DHEAS, orphan drug, CRF1 receptor antagonist