Avasopasem in ROMAN Trial: New Hope for Reducing Severe Oral Mucositis in Cancer Treatment

What Does the ROMAN Trial Reveal About Avasopasem’s Role?

The recent phase 3 ROMAN trial has revealed promising yet complex findings regarding avasopasem manganese (AVA) for reducing chemoradiation-induced severe oral mucositis (SOM) in head and neck cancer patients. This investigational selective dismutase mimetic, which converts superoxide to hydrogen peroxide to protect normal cells from radiation damage, demonstrated statistically significant improvements across several key parameters but fell short of meeting the expectations set by earlier phase 2b results. The trial's outcomes highlight both the potential of this novel therapeutic approach and the challenges in demonstrating conclusive clinical benefit in this difficult-to-treat condition.

The ROMAN trial enrolled 407 patients with locally advanced, nonmetastatic oral cavity or oropharyngeal squamous cell carcinoma who were scheduled to receive standard fractionation intensity-modulated radiation therapy (IMRT) with concurrent cisplatin. Participants were randomized in a 3:2 ratio to receive either avasopasem 90 mg or placebo administered intravenously over 60 minutes before each IMRT session. The study population was well-balanced between treatment arms, with similar baseline characteristics including age, tumor site and stage, human papillomavirus (HPV) status, and planned cisplatin schedule. The primary efficacy endpoint was the incidence of severe oral mucositis (WHO grade 3-4) from the start through the end of IMRT, with secondary endpoints including SOM duration, grade 4 OM incidence and duration, and time to SOM onset. The trial also assessed renal function, supportive care needs, and long-term tumor outcomes.

Are the Efficacy Results Clinically Meaningful?

Results from the ROMAN trial demonstrated that avasopasem significantly reduced SOM incidence compared to placebo (54% vs 64%, p=0.045), representing a relative risk reduction of 16%. While this improvement was statistically significant, it fell short of the 34% reduction predicted based on phase 2b results. More impressively, avasopasem demonstrated a substantial 56% reduction in median SOM duration (8 days vs 18 days, p=0.002) and delayed the median time to SOM onset by 11 days (49 days vs 38 days, p=0.002). Additional exploratory analyses showed that avasopasem significantly reduced SOM incidence at multiple radiation dose landmarks (30, 40, 50, and 60 Gy) with relative reductions ranging from 30% to 50%. These findings suggest that avasopasem provides clinically meaningful benefits throughout the radiation therapy course rather than just at the endpoint of treatment, potentially offering patients substantial relief from this debilitating side effect.

How Safe is Avasopasem in Practice?

The safety profile of avasopasem appeared generally favorable, with most adverse events occurring at similar or lower frequencies compared to placebo. As expected based on its mechanism of action involving nitric oxide potentiation, avasopasem was associated with increased rates of all-grade hypotension (23% vs 19%) and dizziness (28% vs 23%), though grade 3+ events were similar between groups. Interestingly, several radiation and cisplatin-related toxicities occurred less frequently in the avasopasem arm, including radiation skin injury (52% vs 63%), dry mouth (54% vs 63%), acute kidney injury (2% vs 8%), and hypomagnesemia (20% vs 33%). This suggests potential broader protective effects beyond the oral mucosa. Particularly notable was the finding that chronic kidney disease rates at one year were reduced by half in the avasopasem group (14% vs 28%, p=0.009), indicating a possible role for avasopasem in mitigating cisplatin-induced nephrotoxicity, a significant clinical challenge in oncology practice.

Can AVA Enhance Quality of Life and Tumor Outcomes?

The ROMAN trial also assessed the impact of avasopasem on supportive care needs, finding that fewer patients in the avasopasem arm required gastrostomy tube placement after IMRT initiation (21% vs 26%) and fewer used narcotic medications (81% vs 86%). These outcomes, while not statistically significant, suggest potential quality-of-life benefits and reduced healthcare resource utilization. Importantly, tumor control outcomes at one and two years, including overall survival, progression-free survival, and locoregional control, were comparable between treatment arms, indicating that avasopasem did not compromise the efficacy of chemoradiation therapy. This is consistent with preclinical data suggesting that avasopasem selectively protects normal tissues without shielding tumor cells from radiation damage.

What Regulatory Hurdles Remain for AVA?

Despite these encouraging findings, the Food and Drug Administration (FDA) concluded in August 2023 that the ROMAN trial did not provide a sufficiently favorable benefit-risk determination for approval and requested a confirmatory phase 3 trial. This decision was based on several considerations, including the lower-than-predicted reduction in SOM incidence at the primary endpoint, missing follow-up data that weakened the duration endpoint analysis, and numerically higher incidences of thromboembolic events, major adverse cardiac events, and deaths in the avasopasem arm (although these differences were not statistically significant). The trial investigators noted that some of these adverse events might have been influenced by the COVID-19 pandemic, which coincided with the study period, but acknowledged that avasopasem's potential contribution could not be definitively excluded.

Could a Holistic Assessment Improve Oral Mucositis Management?

The ROMAN trial highlights several important considerations for future research in this field. First, it underscores the limitations of using a single endpoint such as incidence to assess the efficacy of interventions for complex, dynamic conditions like oral mucositis. The investigators proposed that a multiparametric approach, such as the generalized pairwise comparisons method used in a post-hoc analysis, might better capture the holistic impact of treatment by simultaneously evaluating multiple clinically relevant outcomes. This analysis revealed a statistically significant net treatment benefit with avasopasem, with a number needed to treat of just 5.3 patients. Second, the trial emphasizes the importance of patient-reported outcomes in assessing the true clinical benefit of interventions, an element that was notably absent from the ROMAN design. Finally, the study raises questions about optimal dosing strategies for avasopasem, as dose reductions due to adverse events were more frequent in the phase 3 trial than in phase 2b and may have contributed to reduced efficacy in some patients.

The management of chemoradiation-induced severe oral mucositis remains an unmet medical need with significant implications for patient quality of life, treatment adherence, and healthcare resource utilization. Could a more comprehensive assessment framework that incorporates both objective clinical measures and patient-reported outcomes provide a more accurate picture of treatment benefit? How might the potential renal protective effects of avasopasem influence its overall clinical utility, particularly in patients receiving multiple cycles of cisplatin? What strategies could be employed to mitigate the vasodilatory side effects associated with avasopasem while preserving its protective benefits? These questions warrant careful consideration as research in this area continues to evolve. The ROMAN trial, despite its limitations, represents an important step forward in our understanding of how targeted interventions can potentially reduce the burden of treatment-related toxicities in cancer care.

Does AVA Offer Meaningful Clinical Benefits?

The results of the ROMAN trial suggest that avasopasem manganese may offer meaningful benefits for patients undergoing chemoradiation for head and neck cancer, particularly in reducing the duration and delaying the onset of severe oral mucositis. While regulatory approval will require additional confirmation, the observed improvements in multiple efficacy parameters, along with potential broader protective effects against radiation and cisplatin toxicities, indicate that this novel therapeutic approach deserves further investigation. As clinical research in this area advances, a more comprehensive evaluation of patient-centered outcomes and refined dosing strategies may help to fully realize the potential of avasopasem and similar agents in enhancing the tolerability of cancer treatment.

Key Trial Outcomes:

• 16% reduction in severe oral mucositis (SOM) incidence (54% vs 64%)
• 56% reduction in SOM duration (8 days vs 18 days)
• 11-day delay in SOM onset (49 days vs 38 days)
• 50% reduction in chronic kidney disease rates at one year (14% vs 28%)
• No compromise in tumor control outcomes at one and two years

How Were Oral Mucositis Assessments Standardized?

One notable aspect of the ROMAN trial was the methodology used for oral mucositis assessment. The trial employed a modified World Health Organization (WHO) scoring system with centralized training and review to ensure consistency and accuracy. Trained evaluators assessed oral mucositis twice weekly during IMRT and weekly for two weeks thereafter, with the WHO scoring defining grade 0 as no mucositis, grade 1 as pain and erythema, grade 2 as ulceration with ability to eat solid food, grade 3 as ulceration with ability to only drink liquids, and grade 4 as ulceration with inability to eat or drink, requiring tube or parenteral feeding. This modified system aimed to distinguish between dietary compromise caused by oral pain versus other confounding factors such as dysgeusia or nausea. The accuracy and consistency of WHO scores were carefully monitored, with 94.9% of initial assessments being consistent with source data and all inconsistencies queried and resolved before final determination.

What Role Do Optimal Dosing Strategies Play?

The dose administration of avasopasem required careful management during the trial. Per protocol, a 25% dose reduction was mandated for grade 2 or greater hypotension occurring within two hours after infusion start or for grade 3-4 adverse events judged likely attributable to the study infusion. In the avasopasem arm, 10% of patients required one 25% dose reduction and 6% required two reductions (total 50% reduction), compared to 5% and 1% in the placebo arm, respectively. Post-hoc analysis suggested that the late increase in SOM incidence observed around day 43 in the avasopasem arm may have been driven primarily by patients who had early dose reductions due to toxicity. This finding highlights the importance of optimal dosing strategies in maximizing the therapeutic benefit of avasopasem while managing its side effects.

Could Multiparametric Analysis Inform Future Trials?

An unplanned secondary analysis using a multiparametric statistical method called generalized pairwise comparisons (GPC) was performed to allow for simultaneous analysis of prioritized clinically relevant outcomes: WHO grade 4 OM incidence, SOM incidence, days of SOM, and days to SOM onset. This analysis showed that avasopasem provided a statistically significant net benefit across all four key outcomes, with a 53.9% probability that avasopasem would benefit patients versus a 35.0% probability for placebo. This translated to a net treatment benefit of 18.9% (95% CI 0.075, 0.303, p=0.0012) and a number needed to treat of just 5.3 patients. This approach provides a more holistic assessment of treatment impact than single-endpoint analyses and may be valuable for future trial designs in this therapeutic area.

Important Safety & Regulatory Considerations:

• Generally favorable safety profile with most adverse events similar to placebo
• Higher rates of hypotension (23% vs 19%) and dizziness (28% vs 23%)
• FDA requested additional confirmatory trials due to:
  • Lower-than-predicted reduction in SOM incidence
  • Missing follow-up data
  • Concerns about thromboembolic events and cardiac events

How Did the COVID-19 Pandemic Affect the Trial?

The ROMAN trial was conducted during the COVID-19 pandemic, which presented additional challenges for patient management and data collection. Concerns about disease transmission during close examination of the mouth, especially early in the pandemic when understanding of COVID-19 transmission was limited and personal protective equipment was scarce, affected oral mucositis assessments. Additionally, the investigators hypothesized that COVID-19 may have contributed to cardiac and thromboembolic events as well as non-oncologic deaths not previously observed in the phase 2b trial, particularly since several of these events were clustered at known COVID-19 hotspots. While the investigators considered it unlikely based on previous data, they could not definitively exclude avasopasem as a contributing factor to these adverse events.

What Do Preclinical Insights Reveal About AVA?

Preclinical studies have provided mechanistic insights into avasopasem's effects, showing that superoxide plays a key role in cisplatin-induced kidney damage and that avasopasem can prevent this damage. Nonclinical research also supports the expectation that avasopasem does not reduce the antitumor effect of chemoradiation therapy and may even enhance radiation efficacy at higher fraction doses. These findings are consistent with the clinical observations in the ROMAN trial, where tumor outcomes remained comparable between treatment arms while certain toxicities appeared reduced. Recent bench research suggests that avasopasem may persist in mitochondria for several days, raising the possibility that less frequent administration schedules might be feasible and worthy of investigation in future studies.

What Were the Key Limitations of the ROMAN Trial?

The limitations of the ROMAN trial included the absence of a separate patient-reported outcome instrument, which was considered during phase 3 design but ultimately not implemented due to concerns about confounding factors impacting quality of life during head and neck cancer chemoradiation therapy. The investigators noted that even with significant decreases in SOM incidence and duration, patients might still rate their quality of life poorly without a frame of reference for how much worse their experience could have been in the placebo setting. Additionally, the trial did not assess other long-term complications of head and neck radiotherapy, such as xerostomia and trismus, and OM follow-up was limited to two weeks after radiotherapy, potentially missing information about SOM resolution patterns.

Where Should Future Research Focus?

Future research directions suggested by the ROMAN findings include the need for more comprehensive evaluation frameworks that better capture the multidimensional impact of interventions for oral mucositis. The investigators proposed that future trial designs might benefit from inclusion of a multiparametric endpoint, patient-reported outcomes, and resource management analysis. Additionally, further investigation of avasopasem's potential to mitigate radiation and cisplatin injury in other clinical contexts appears warranted based on the observed reductions in various toxicities beyond oral mucositis. The development of strategies to manage the vasodilatory side effects of avasopasem while maintaining its protective benefits represents another important area for future research.

Summary

The ROMAN phase 3 trial investigated avasopasem manganese (AVA) in 407 patients with head and neck cancer receiving chemoradiation. The study demonstrated a 16% reduction in severe oral mucositis (SOM) incidence (54% vs 64%), a 56% reduction in SOM duration (8 vs 18 days), and delayed onset by 11 days compared to placebo. While the safety profile was generally favorable, the FDA requested additional confirmatory trials due to lower-than-predicted efficacy and some safety concerns. The trial revealed potential broader protective effects, including reduced kidney disease rates and radiation-related toxicities. Despite not meeting full regulatory requirements, the results suggest meaningful clinical benefits and warrant further investigation, particularly regarding optimal dosing strategies and comprehensive patient outcome assessments.